,qwhuqdwlrqdo&rqihuhqfhrq …ammconf.com/amm2019_proceeding.pdfhow boeing manages innovation...

Sung Yi, Portland State University, USA Sang Mok Lee, Korea Institute of Industrial Technology, KOREA Chien Wern, Portland State University, USA

Proceedings of

International Conference on Advanced Materials and

Manufacturing

August 20-23, 2019

Portland State University

This is the version of the booklet for print use. The electronic version of this booklet can

be found at:

https://ammconf.com

Contents

About 6

AMM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

International Organizing and Scienti�c Committee . . . . . . . . . . . . . . . 6

Timetable 7

Wednesday, August 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Thursday, August 22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Friday, August 23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Preface 10

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

List of Abstracts � Talks 11

Wednesday 21st . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

How Boeing Manages Innovation (William Gerry) . . . . . . . . . . . . . . . . 11

Flexible Manufacturing Technology Coping with the 4th Industrial Revolution

(Sang-Mok Lee) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

A Study of Injection-Molding Technique with 3D-Printed Polymer Core for

Consistent Plastic Molding (Sunghyun Shin, Euichul Jeong, Kyunghwan

Yoon, and Sunghee Lee) . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Surface Properties Characterization of Plastic 3D-Printed Molds (Nguyen Le1,

Jesik Shin2, and Sung Yi1) . . . . . . . . . . . . . . . . . . . . . . . . . 12

A Study on Rapid Soft Tooling for Investment Casting (Jesik Shin1, Jiwoon

Lee1, Hoon Cho1, Yong-Dae Kim1, Kwangho Shin1, Seung Mok Yoo1,

and Sung Yi2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

A Simple Device for the Measuring Mechanical Properties of Polymers (Faryar

Etesami) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Lubricant Engineering for the Future (Sergei Glavatskih) . . . . . . . . . . . . 14

3D Manufacturing: Challenges and Future Trends (Trevor Synder and Mike

Norkitis) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Development of Hybrid 3DP based on FDM for Huge Wooden Patterns (Jeongsu

Lee, Youngchul Lee, Byounjun Lee, and Jeongtae Kim) . . . . . . . . . . 14

Surface Roughness and Gloss of Polypropylene Injection Molded Parts made

with Polymer AM Mold Inserts (Ahmed Sdir Loza1, Sleight Halley1, Trevor

Synder2, Mike Norkitis2, Jesik Shin3, and Sung Yi1) . . . . . . . . . . . . 15

3

Synthesis of Bulk Nanostructured Lightweight Alloys through Phase Competition

of Amorphous Precursors (Song-Yi Kim, Hyun-Ah Kim, A-Young Lee,

Haneul Jang and Min-Ha Lee) . . . . . . . . . . . . . . . . . . . . . . . 16

Analytical Modeling of Geometric Characteristics in Lattice Structures for

Extrusion-based Additive Manufacturing based on Fluid Mechanics (Jiwoon

Lee1, Jesse M. Walker2, Sanjay Natarajan2, and Sung Yi2) . . . . . . . . 17

E�ects of Argon-hydrogen Plasma Deoxidation on Molten Ti-6Al-4V Alloy

(Byungmoon Moon and Hyundo Jung) . . . . . . . . . . . . . . . . . . . 17

Thursday 22nd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Uphill Quenching for Aluminum Alloys: Process Overview and Update Relative

to Mechanical Properties for AA7075-T6 (W. Mattos1, G. Totten2, and

L. Canale3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Tool Wear Evaluation for Ti6Al4V Alloy using Cryogenic Machining System

(Kangwoo Shin, Jung-Soo Nam, Hyo-Young Kim, Seok-Woo Lee, and

Tae-Gon Kim) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Optimization of Machining Parameters for Milling Operations (Yubin Lee, Chien

Wern, and Sung Yi) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Geometry-Based Machining Simulation of Carbon Fiber Reinforced Polymer

(CFRP) Composites (Xingyu Fu, Kyeongeun Song, and Martin B.G. Jun ) 19

An Investigation of Enhancement in Mechanical Properties of Carbon/PEKK

Laminates by Die Quenching Process (Insung Huh, Yongjun Jeon, Hwanju

Lee, Hyeonsuk Choi, Geonhyun Yu, Sitae Won, Hoon Cho, and Dongearn

Kim) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Applications and Challenges of Flexible Composite Structures (Kevin Cox) . . 20

Design Re�nement of Multifunctional Mechano-Luminescence-Optoelectronic

Composites for Improved Self-Powered Strain Sensing Capability (Jeromy

Trullio, Setayesh Fakhimi, Alfred Mongare, and Donghyeon Ryu) . . . . . 21

The Role of Grain-Boundaries on the Evolution of Allotriomorphic Alpha in

Titanium Alloys (V. Dixit1, G.B. Viswanathan2, W.A.T. Clark2, and H.L.

Fraser2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Fabrication of High Strength Aluminum Alloy Sheets by Twin Roll Casting and

Rolling Process (Hyoung-WooK Kim, Yun-Soo Lee, Min-Seok Kim, and

Cha-Yong Lim) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Fatigue Behaviors of A Newly Developed ECO-7175-v3 Extruded Aluminum

Alloy (Chinh Vu1, Chien Wern1, Bong-Hwan Kim2, Shae Kwang Kim2,

Ho-Joon Choi2, and Sung Yi1) . . . . . . . . . . . . . . . . . . . . . . . 23

Synthesis of Copper Nanowire and Eco-friendly Fabrication Method of Cu-Ag

Nanowire (Suhyun Lee and Sung Yi) . . . . . . . . . . . . . . . . . . . . 23

A Study of Thermal Energy Storage Systems of Phase Change Materials

(Kyung-Eun Min1, So-Jung Lee2, Jun Ki Kim2, and Sung Yi1) . . . . . . 24

4

List of Posters 26

Poster Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Development of High-Mg Containing AlMg Wrought Alloys with High Strength

and High Ductility for Lightweight Purpose of Transportation Industries

(Seong-H. Ha, Young-O. Yoon, Hyun-K. Lim, and Shae K. Kim) . . . . . 26

E�ect of Continuous Welding on Microstructure and Mechanical Properties of

Angle and T-bar (Jihoon Jang, Changsuk Yoon, Yongjae Lee, Sangik Lee,

and Dong-Geun Lee) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Heat Transfer Characteristics of Bulkhead Penetration Piece for A-Class Com-

partment of Ship and O�shore Plant (Chang Yong Song and Jonghwan

Park) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Fabrication of Plastics/Metal Hybrid Multi-Components using the DSI (die slide

injection) molding for Electrical Conductor Applications (Seok-Jae Ha,

Min-Kyu Son, Jun-Young Jang, Young-Bae Ko, and Baeg-Soon Cha) . . 27

In�uence of Cutting Heat on Machining Titanium Materials by Combining MQL

(Minimum Quantity Lubrication) and Cryogenic Air Spraying (Ki-Hyeok

Song, Seok-Jae Ha, and Gil-Sang Yoon) . . . . . . . . . . . . . . . . . . 28

Alloy design of ECO-Al 7175 Alloys and Analysis of Their Mechanical and

Corrosion Properties (Seung-Yoon Yang1;2, Bong-Hwan Kim2, Da-Bin

Lee2, Kweon-Hoon Choi2, Nam-Seok Kim2, Seong-Ho Ha2, Young-Ok

Yoon2, Hyun-Kyu Lim2, Shae K. Kim2, and Young-Jig Kim2) . . . . . . . 29

E�ect of Multiple Forging on Microstructure and Tensile Property of Al-Mg

Alloy Castings Containing High Content of Mg (Seong-Ho Ha, Young-Chul

Shin, Young-Ok Yoon, Bong-Hwan Kim, Hyun-Kyu Lim, and Shae K. Kim) 30

A New Multiforging Test Method for Forgeability Assessment of Aluminum

Alloys (Young-Chul Shin, Seong-Ho Ha, Ji-Woon Lee, Dae-Kwan Joung,

Ho-joon Choi, Seung-Mok Yoo) . . . . . . . . . . . . . . . . . . . . . . 30

A Study on Adhesive Bonding Behavior for Car Body Assembly of CFRP-metal

Dissimilar Materials (So-Jeong Lee, Da-In Lim, and Jun-Ki Kim) . . . . . 31

The Study about Die and Mold Manufacturing with a Direct Energy Deposition

(DED) Additive Manufacturing Process (Woo Sung Kim, Myung Pyo

Hong, Yoon Sun Lee, Min Gyu Lee, and Ji Hyun Sung) . . . . . . . . . . 32

Partner Institutions and Sponsors 33

Partner Institute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Sponsors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5

About

AMM

The purpose of the conference is to promote awareness of new advances in materials,

material design, material fabrication and reliability of materials. This will also provide

an excellent opportunity for researchers and engineers to gather to discuss generic and

practical applications and new directions. The Organizing Committee seeks original papers

that demonstrate how new technologies and applications are expanding and rede�ning

the international role of advanced materials and their manufacturing. Contributions are

very welcome from industry participants and researchers from academic institutions.

International Organizing and Scienti�c Committee

Cheolhee Kim Ho-joon Choi Faryar Etesami

Soong-Keun Hyun Jesik Shin Youngchul Shin

Hyungwook Kim Sangchan Lee Ji Woon Lee

Hacheol Song Phil Geng Lianxi Shen

Shaestagir Chowdhury Huy Le Megumi Kawasaki

6

Timetable

PL: Plenary Talk, CM: Composite Materials, LM: Light Weight Metals and Alloys, RT:

Rapid Tooling, SM: Subtractive Manufacturing

Wednesday, August 21

8:30�9:00 Registration

8:50�9:00 Opening remarks

9:00�9:40 PLWilliam Gerry

Boeing Company, USAHow Boeing Manages Innovation

9:40�10:20 PL

Sang-Mok Lee

Korea Institute of

Industrial Technology,

Korea

Flexible Manufacturing Technology

coping with the 4th Industrial

Revolution

10:20�10:40 Co�ee Break

10:40�12:00 RT

Session Chair: Faryar

Etesami

Portland State University,

USA

Flexible Manufacturing & Rapid

Tooling I

Lunch Meeting:

12:00�1:30 KITECH-OMIC-PSU Meeting: EB402L

12:00�1:30 Subtractive Manufacturing : EB402K

12:00�1:30 Flexible Manufacturing & Rapid Tooling: EB510

12:00�1:30 Composite Materials: Terrace outside EB510

12:00�1:30 Light Weight Metals & Alloys: EB 3th Floor

13:30�14:10 PL

Sergei Glavatskih

Royal Institute of

Technology, Sweden

Lubricant Engineering for the

Future

14:10�14:50 PL

Trevor Synder and Mike

Norkitis

3D Systems, OR, USA

3D Manufacturing: Challenges and

Future Trends

14:50�15:10 Co�ee Break

15:10�16:50 RT

Session Chair: Jeong

Han Kim

Inha University, Korea

Flexible Manufacturing & Rapid

Tooling II

16:50�18:00 Poster session

18:00�20:30 Dinner

7

Thursday, August 22

9:00-9:40 PL

W. Mattos, G. Totten,

and L. Canale

Federal Institute of Sao

Paulo,Sao Carlos, Brazil,


OR, USA, Sao Paulo

University, Brazil

Uphill Quenching for Aluminum

Alloys: Process Overview and

Update Relative to Mechanical

Properties for AA7075-T6

9:40�10:40 SM

Session Chair: Kyeong

Kyun Lee

Korea Institute of


Korea

Subtractive Manufacturing

10:40�11:00 Co�ee Break

11:00�12:00CM

Session Chair: Seung

Mok Yoo

Korea Institute of


Korea

Composite Materials

12:00�13:30 Lunch

13:30�15:10 LM

Session Chair: Ho-Joon

Choi

Korea Institute of


Korea

Light Weight Metals and Alloys

15:10�16:00 Poster Session

16:00�16:30 Award and Closing

18:00�21:30 Conference Dinner

Friday, August 23

9:00�12:00 RT

Sung Yi


USA

Visit 3D Systems

8

Preface

Preface

This proceeding contains the abstracts presented at 2019 International Conference on

advanced materials and manufactruing held on August 20-23, 2019, in Portland, Oregon,

USA. It includes a total of 35 abstracts with authors coming from Brazil, Korea, Sweden,

and the United States of America.

This conference helps identify future directions of development in this area of advanced

materials and manufactruing. It is our earnest hope that the publication of this proceeding

will help broaden awareness within the engineering community of the recent advances in

materials and manufactruing and will serve the profession well.

The editors express their sincere thanks to all the authors who have contributed to the

proceeding. Special thanks go to George Totten, Kyeong Kyun Lee, Seung Mok Yoo,

Ho-joon Choi, Cheolhee Kim, Soong-Keun Hyun, Jesik Shin, and Ji Woon Lee for their

hard work to make the conference possible.

Sung Yi, Sang-Mok Lee, and Chien Wern

10

List of Abstracts � Talks

Wednesday 21st

How Boeing Manages Innovation

William Gerry

Boeing Company, USA

Flexible Manufacturing Technology Coping with the 4th IndustrialRevolution

Sang-Mok Lee

Korea Institute of Industrial Technology, Korea

A Study of Injection-Molding Technique with 3D-Printed PolymerCore for Consistent Plastic Molding

Sunghyun Shin, Euichul Jeong, Kyunghwan Yoon, and Sunghee Lee


In this paper, injection molding technique with 3D printed polymer core was performed

to fabricate hundreds of injection molded plastic products. The core was made of nylon-

based PA2200 powder material. Metal core was also manufactured by conventional

machining method to compare the dimensional di�erences between two cores. To monitor

temperature variation during injection molding cycles, cavity temperature sensor was

11

installed in the polymer core. As the material of 3D printed core has lower sti�ness and

thermal conductivity compared with the metal core material of tool steel, cooling time

of the polymer core was adjusted longer than that of metal core in injection molding

experiment. The other remaining processing conditions such as injection, packing were set

the same. Crystalline resin of polypropylene and amorphous resin of polystyrene with low

melting temperature and viscosity were selected for the injection molding experiment. The

thickness shrinkage of the molded part compared to the mold core depth was measured

from the gate by a constant interval. It was shown that the application of cooling channel

in the polymer core could enable to maintain the mold temperature within 2 degree C

and dimensional accuracy of less than 1% over 200 continuous molding processes and

the thickness shrinkage of the injection molded parts from the 3D printing core was

2.02 4.34% larger than that of metal core.

Surface Properties Characterization of Plastic 3D-Printed Molds

Nguyen Le1, Jesik Shin2, and Sung Yi1

1 Portland State University, OR, USA and 2 Korea Institute of Industrial Technology, Korea

Surface Properties Characterization of Plastic 3D-Printed Molds Nguyen Le, Sung Yi

One of the most recent and interesting 3-D printing applications is the 3-D printed

plastic mold which can be an alternative to traditional metal mold for plastic products

by injection molding process. As surface �nish of the 3-D printed plastic mold is crucial

to the appearance and the performance of the �nal product, coating as the �nal step is

implemented to ensure the desired surface characteristics of the mold due to the geometric

complexity. To better understand and characterize the mold surface, wettability and

surface free energy (SFE) of this 3-D printed material have been studied. Three di�erent

surfaces have been examined for understanding the relationship between contact angle,

surface roughness, and the total SFE. The total SFE is calculated by employing a group

of liquids using di�erent theoretical methods and then compared with that obtained with

a statistical analysis. Results show that SFE values obtained with di�erent methods agree

with each other within a reasonable error band and the isotropy of surface roughness is

crucial for the agreement.

A Study on Rapid Soft Tooling for Investment Casting

12

Jesik Shin1, Jiwoon Lee1, Hoon Cho1, Yong-Dae Kim1, Kwangho Shin1, Seung Mok

Yoo1, and Sung Yi2

1Korea Institute of Industrial Technology, Korea and 2Portland State University, OR, USA

A study on rapid soft tooling and wax injection molding processes were carried out to

develop a RT-based investment casting process for small to medium volume production.

Before manufacturing the core mold to injection mold a stepped tube wax casting pattern,

solidi�cation characteristics of wax materials according to mold design including conformal

cooling channels were analyzed using Solidworks 2017. The core molds were made of

various polymeric materials using MultiJet printing, a variant technique of FDM (fused

deposition modelling), of 3D Systems, Inc. The e�ects of surface treating and cooling

conditions of the 3D printed core molds on sound �lling of molten wax and release of

solidi�ed wax pattern were investigated.

A Simple Device for the Measuring Mechanical Properties ofPolymers

Faryar Etesami

Portland State University, OR, USA

Additive manufacturing technology has become a viable solution for making molds for

plastic injection molding applications. The molds are usually made of high temperature

plastic resins suitable for plastic injection molding. Molding resins have superior mechanical

properties necessary to withstand the high temperatures and pressures of the injection

molding process. It is known that high temperature mechanical properties of resins

in�uence mold performance but it is not established which properties are most important

and to what extent they in�uence the mold performance. Identifying the most important

properties in�uencing mold performance would help resin manufacturers to develop better

mold-making materials. In order to study the performance of mold materials we have

designed a simple device for measuring the mechanical properties of 3D printed resins

including their strength, surface hardness, and wear resistance at molding temperatures

of up to 260 degree C. We then quanti�ed the mechanical properties of three high-

temperature resins along with ABS at the injection molding temperatures. This paper

describes the test device and the results of characterizing the materials properties,

measuring methods and applications.

13

Lubricant Engineering for the Future

Sergei Glavatskih

KTH Royal Institute of Technology, Stockholm, Sweden

Our society is more dependent than it has ever been on mechanical machinery, not

only in the transport sector, but also in energy generation systems, with wind turbines

being an obvious example. A machine needs reliable lubrication to maximize energy

e�ciency, functionality and durability. Automation and power density in many machines

are increasing. This trend escalates the demands on high-performance lubricants. New

lubrication technologies should also comply with growing environmental awareness and

a strive towards carbon neutral societies. This talk will demonstrate how new lubricant

design strategies and novel materials can address these performance and environmental

challenges. A number of examples related to energy, manufacturing and automotive

sectors will be presented. We will discuss applications of biodegradable oils, hybrid �uids

and greases. An insight into how lubricant performance can be enhanced by using ionic

materials will be given. Finally, it will be shown how ionic materials can deliver new

functionality, such as controllability, unachievable with traditional molecular lubricant

formulations.

3D Manufacturing: Challenges and Future Trends

Trevor Synder and Mike Norkitis

3D Systems, OR, USA

Development of Hybrid 3DP based on FDM for Huge WoodenPatterns

Jeongsu Lee, Youngchul Lee, Byounjun Lee, and Jeongtae Kim


14

Due to recent rapid changes in the corporate environment, most of the wooden pattern

factories have di�culties in management due to internal labor shortages, aging of the

workforce, and demand for a drastic improvement in the work environment. Externally,

production and supply of high-quality castings for customers and ful�llment of various

needs have become urgent tasks. In order to e�ciently cope with this situation, it is

absolutely required to develop a new type wooden pattern machine for innovating a wooden

factory. A hybrid method of combining an extruder and a NC machine was adopted and we

have developed a whole system covering large extruders, related materials and dedicated

S / W. The detailed technologies developed for whole system are as follows - Working

size applicable to large castings (3m, 4m, 1.2m) - Rapid stacking using up to 15 mm x

15 mm extrusion nozzles - Gantry type mounting unit for extruder and machining head -

Developed the optimum material (PLA + ABS) for wooden replacement - Development

of dedicated S/W for hybrid 3D printer Finally, the whole system was completed by

�nding the optimum RPM and speed of tools for resin materials and developing additional

equipment (material supply device, etc.) for commercialization.

Surface Roughness and Gloss of Polypropylene Injection MoldedParts made with Polymer AM Mold Inserts

Ahmed Sdir Loza1, Sleight Halley1, Trevor Synder2, Mike Norkitis2, Jesik Shin3, and Sung

Yi1

1Portland State University, OR, USA , 23D Systems , OR, USA, and 3Korea Institute of Industrial

Technology, Korea

Plastic injection mold inserts were printed with Stereolithography technology (SLA) using

FormLabs Form1 printer and the High Temp V1 clear resin. Three sets of molds were

printed using Multi Jet Printing technology (MJP) from 3D Systems in the ProJet MJP

2500 printer, with M2G-CL, M2R-CL and a Novel Material (NM1) as the materials chosen

for the study, due to their high tensile strength, Coe�cient of Thermal Expansion (CTE)

and Heat De�ection Temperature (HDT) . Two di�erent designs were used with the

purpose of testing the surface features of the injected parts, each set with three di�erent

printing orientations: face up, face down and side up. In order to test the printed parts for

dimensional accuracy and �atness tolerancing, a Coordinate Measuring Machine (CMM)

was used taking twelve points as reference on each face, plus an additional one for the

cavity for a total of seven. The mold inserts printed with the High Temp resin from

FormLabs were too warped to �t into the MUD, so no parts were successfully made. The

�attest mold across all faces was the one printed using the NM1 side up, and the material

with the lowest numbers counting all printing orientations was the M2G-CL (Armor) from

15

3D Systems. Poly propylene test parts were molded with the M2G-CL and NM1 inserts

to test the surface roughness, gloss, and dimensional stability of the injected part. It was

found that print direction of the M2G-CL and NM1 mold inserts in�uenced the gloss

and surface roughness of the injected part, with the highest gloss and lowers surface

roughness obtained from the inserts printed face up. Fine features of injected parts were

close to the desired dimension, but trouble with complete �lling of the mold limited the

success of these parts.

Synthesis of Bulk Nanostructured Lightweight Alloys through PhaseCompetition of Amorphous Precursors

Song-Yi Kim, Hyun-Ah Kim, A-Young Lee, Haneul Jang and Min-Ha Lee


It has been made with many e�orts to produce a light weight and high strength materials

with the acceleration of transport development and energy conservation. In particular,

high strength aluminum or magnesium based alloys are gradually substituting steel and

cast iron in automotive and aerospace industries to reduce the weight of the vehicles in

order to decrease fuel consumption. To produce high strength nanostructured light weight

alloys, several methods have been applied, such as heat treatment and grain re�nement.

Recently rapid solidi�cation and mechanical alloying techniques are used to produce high

strength nanostructured light weight alloys. In current study, synthesis method and

characterization of high strength nanostructured light weight alloys (Al-, Mg-) have been

studied. We report the methods increasing both strength and ductility of light weight

alloys transformed from amorphous precursor. Thermal stability as well as mechanical

property of nanostructured light weight alloys has been investigated. Rapid solidi�ed

amorphous precursor powder was synthesized and consolidated by the gas atomization and

spark plasma sintering (SPS) methods. Mechanical property of consolidated specimens

was evaluated by room temperature compression test. The precipitation of intermetallic

phases by crystallization of the remaining amorphous matrix plays important role to restrict

the growth of the primary phase and contributes to the improvement of the mechanical

properties. Such fully crystalline nano- or ultra�ne-scale microstructures are considered

promising for industrial application because their superior mechanical properties in terms

of a combination of very high room temperature strength combined with good ductility.

16

Analytical Modeling of Geometric Characteristics in LatticeStructures for Extrusion-based Additive Manufacturing based on

Fluid Mechanics

Jiwoon Lee1, Jesse M. Walker2, Sanjay Natarajan2, and Sung Yi2

1Korea Institute of Industrial Technology, Korea and 2Portland State University, OR, USA

Extrusion-based additive manufacturing is known as a promising technique to fabricate the

lattice structure due to a�ordability, versatility, and wide acceptance of various materials.

The reliability and controllability of the printing process are necessary to produce lattice

structures with desired properties. Analytical models are developed in this study to

simulate the geometric characteristics of cylindrical sca�olds produced by extrusion-based

additive manufacturing technique using �uid mechanics. The geometric characteristics of

the lattice structure can be predicted by using extrusion pressure, temperature, nozzle

diameter, nozzle length, and printing speed. The e�ectiveness of models is veri�ed

through comparison with the experimental results. Simulation results show that geometric

characteristics have a strong relationship with processing parameters, and the developed

models are useful in predicting the properties of lattice structure in the extrusion-based

additive manufacturing process.

E�ects of Argon-hydrogen Plasma Deoxidation on MoltenTi-6Al-4V Alloy

Byungmoon Moon and Hyundo Jung


This study presents the e�ective reduction of oxygen content that deteriorates the

mechanical properties of recycled Ti-6Al-4V alloy. The deoxidation phenomenon was

investigated by the reaction between oxygen and hydrogen through electromagnetically

induced scrap melting and argon-hydrogen plasma treatment. Preferentially, titanium

scrap metal was continuously fed into a cold crucible and melted by electromagnetic

induction heating. Then, the melt was pulled down to make a 355-mm-high ingot.

Oxygen gas content analysis was performed before and after the plasma re�ning process.

Argon-hydrogen plasma re�ning was performed in the cold crucible with induction melting.

The Gibbs free energy change of the oxidation/deoxidation reactions were calculated. The

oxygen content of recycled Ti-6Al-4V was decreased until the �ow ratio of hydrogen/argon

17

plasma gas increased to 40 vol%. And mechanical properties of this alloy was investigated

to make enlargement of its application to the ELI Grade titanium alloy used for bio-implant

material.

Thursday 22nd

Uphill Quenching for Aluminum Alloys: Process Overview andUpdate Relative to Mechanical Properties for AA7075-T6

W. Mattos1, G. Totten2, and L. Canale3

1Federal Institute of Sao Paulo, Sao Carlos, Brazil, 2Portland State University, OR, USA, and3Sao Paulo University, Brazil

This work presents two main objectives. First, an overview of the uphill quenching process

used in heat treatment of aluminum alloys. This process was developed by Alcoa in the

late 50's for reducing residual stress e�ects after water quenching.

Tool Wear Evaluation for Ti6Al4V Alloy using Cryogenic MachiningSystem

Kangwoo Shin, Jung-Soo Nam, Hyo-Young Kim, Seok-Woo Lee, and Tae-Gon Kim


Productivity in the machining of Ti6Al4V alloys is adversely a�ected by rapid tool wear

as a consequence of high cutting zone temperature due to low thermal conductivity

of material. Therefore, e�ective cooling is required during cutting process of Ti6Al4V

parts. However, conventional cutting method, such as cutting �uids is insu�cient to cool

down of cutting temperature. To cool down cutting temperature e�ectively, cryogenic

machining using liquid nitrogen has been suggested. In this study, tool wear is evaluated

for Ti6Al4V alloy using cryogenic machining system. Solid end mill and indexable cutting

tool were used to machining the pocket shape of Ti6Al4V alloys. Tool wear was compared

versus conventional �ood cooling method. Materials and Machining

18

Optimization of Machining Parameters for Milling Operations

Yubin Lee, Chien Wern, and Sung Yi


In general, minimum production cost or minimum production time has been considered as

the objective function made to optimize machining parameters. Although a low production

time would mean low production cost, it should be realized that machining parameters

giving minimum production time would not be identical to those giving minimum production

cost. In this project, the maximum pro�t rate will be studied to compromise between

these two criteria. Optimum parameters for maximum pro�t rate always lie between

those of minimum production cost and minimum production time. Unless the pro�t is

very high, machining parameters for maximum pro�t rate are close to those of minimum

production cost. In this paper, a numerical method has been formulated to optimize the

machining process. The cutting speed and feed per tooth are considered as the design

variables for the CNC milling operation. The Nelder-Mead Simplex method was employed

together with the exterior penalty method for solving the present constrained optimization

problem. One case study has been conducted to demonstrate the accuray of the present

formulation. In this case study, a part was to be produced using computer numerical

control (CNC) milling machine and optimum machining parameters for the maximum

pro�t rate were obtained.

Geometry-Based Machining Simulation of Carbon Fiber ReinforcedPolymer (CFRP) Composites

Xingyu Fu, Kyeongeun Song, and Martin B.G. Jun

Purdue University, Lafayette, IN, USA

Material with high strength and highly corrosion resistance, and hence is widely applied

in aerospace industries. However, milling of CFRP usually generates machining defects

(for instance, delamination and pull-out �bres), making processed surface unquali�ed

to meet the requirement of aerospace application. Therefore, prediction for machining

quality should be conducted before milling processing to avoid potential loss in massive

production. In this paper, a geometrical calculation software for CFRP milling is provided

based on Dexel model. The software can generate geometrical parameters, for example,

cutting angle, cutting length and engagement angle, for the whole milling process.

19

An Investigation of Enhancement in Mechanical Properties ofCarbon/PEKK Laminates by Die Quenching Process

Insung Huh, Yongjun Jeon, Hwanju Lee, Hyeonsuk Choi, Geonhyun Yu, Sitae Won, Hoon

Cho, and Dongearn Kim


Carbon �ber reinforced plastic (CFRP) composites are being spotlighted as new alternative

materials for the conventional metal materials due to their excellent properties including

high speci�c strength, high speci�c sti�ness, and a high cycle fatigue life. Among CFRP

composites, thermoplastic composites show better performance both in impact resistant

and thermal resistance than the existing thermosetting composites and can also be

fabricated by a fast forming process. For this reason, the application of high-performance

thermoplastic composites to secondary structures such as aircraft ribs and clips is on

the rise. Since aerospace-grade thermoplastics, such as PPS, PEEK, and PEKK are

semi-crystalline, the degree of crystallinity of its composites should be controlled to secure

satisfactory mechanical properties and corrosion resistance. The traditional process using

an autoclave has fabricated high-quality composite products, which had been formed at

high pressure, at a constant slow cooling rate. However, this process requires a long

cycle time and an enormous process cost. This study applied a rapid cooling method

to a carbon/PEKK laminate in a press forming process in order to see whether the

mechanical properties thus obtained would be similar to those of the existing process.

For the experiment, a laminate was fabricated by press consolidating UD-Carbon/PEKK

tape 16plies with a quasi-isotropic layup. Then, the laminate was heated up to above the

melting temperature by an infrared heater. In this way, the thermal history was removed

from the laminate. The die-quenching was performed at di�erent mold temperatures (RT,

170, 200, 230 degree C) to control the cooling rate. Di�erential scanning calorimeter

measurement was used to obtain the crystallinity of a formed product according to cooling

rate. The correlation between crystallinity and interlaminar shear strength was analyzed

through a short beam test. Finally, the morphologies of laminates, which were acquired by

the slow cooling and the die quenching respectively, were compared by using transmission

electron microscopy. When laminates were formed at a mold temperature above 200

degree C, that is, near the cold crystallization temperature, their average crystallinity was

measured to be 28%. This result was similar to that of the traditional method.

Applications and Challenges of Flexible Composite Structures

Kevin Cox

20

Ember LLC, USA

Composites are being increasingly recognized for their suitability in the most speci�c and

demanding sectors across many industries. Advantages of composite materials such as

lightweight, resistance to a wide range of �uids, good thermal insulation, excellent damping

and fatigue performance, high strength, and �exibility make them ideal candidates for use

in structural applications. These properties combined with the unmatched tailorability

of �ber reinforcements along load paths have motivated various industries to promote

the use of composites in critical load-bearing applications. Of focus in this article are

�exible structures, which implement composites due to their high strain capabilities. The

applications reviewed center on multi-megawatt blades for wind turbines, coiled tubing for

oil and gas well intervention, and deployable booms for spacecraft structures. The design

challenges of these �exible structures and the capabilities provided by �ber-reinforced

plastics are discussed.

Design Re�nement of MultifunctionalMechano-Luminescence-Optoelectronic Composites for Improved

Self-Powered Strain Sensing Capability

Jeromy Trullio, Setayesh Fakhimi, Alfred Mongare, and Donghyeon Ryu

Contact:[email protected], New Mexico Tech, NM, USA

The mechano-luminescence-optoelectronic (MLO) composites were invented by Ryu, and

MLO composites prototypes were fabricated using two functional building blocks: 1)

conjugated poly(3-hexylthiophene) (P3HT) polymer and 2) mechano-luminescent (ML)

copper-doped zinc sul�de (ZnS:Cu). The p-type semiconducting P3HT polymer forms p-n

bulk hetero-junction (BHJ) microstructures in thin �lm con�guration by being blended with

an n-type semiconducting polymer. The P3HT-based thin �lm is well known to generate

DC electricity under radiant energy (i.e., light). Beyond the radiant-electrical energy

harvesting capability of the P3HT-based thin �lm, Ryu reported mechano-optoelectronic

(MO) properties of the P3HT-based thin �lm by showing that the DC current generated

under light varied with tensile strain applied onto the thin �lm. On the other hand, the

ML ZnS:Cu is a well-known elastic ML material exhibiting light emission in response

to mechanical stimuli over numerous cycles. The initial design of MLO composites

was provoked by an idea to couple the unique multiphysics MO and ML properties of

the functional building blocks (i.e., P3HT and ZnS:Cu, respectively). Recent studies

showed that the assembled composites (i.e., MLO composites) of P3HT-based thin �lm

21

and ZnS:Cu-based elastomeric composites exhibited self-powered strain sensing using

DC voltage generated under mechanical vibration. In this study, we aim to enhance

performance of MLO composites by re�ning the current design of the MLO composites

based on in-depth understanding of functional building blocks' multiphysics properties.

First, ZnS:Cu-based elastomeric composites are used for preparing test specimens in

a dog bone shape, and the specimens are subjected to cyclic tensile loading/unloading

cycles. Two high-speed cameras are employed for recording video footages of ML light

emitted from the specimen and acquiring digital image correlation (DIC)-based strain

information. Through an image processing technique, the video footages recording ML

light produce 2D mapping of ML light intensity. The 2D-mapped light intensity is related

to the DIC-based strain.

The Role of Grain-Boundaries on the Evolution of AllotriomorphicAlpha in Titanium Alloys

V. Dixit1, G.B. Viswanathan2, W.A.T. Clark2, and H.L. Fraser2

1Intel Corporation and 2Ohio State University, OH, USA

Grain boundaries have an important role on microstructural evolution and resultant prop-

erties in beta-processed titanium alloys, especially in near-alpha and alpha+beta regimes.

Below the beta-transus temperature, the initial heterogeneous precipitation of allotriomor-

phic or grain-boundary alpha (or GBA) phase occurring at grain-boundaries is known to

exhibit a long-range in�uence on the subsequent intragranular microstructural evolution.

In this work, the importance of all grain-boundary parameters, namely misorientation

angle/axis and grain-boundary plane, will be discussed on both crystallographic variant

selection and the thickness of GBA in Ti-5553 and Ti-550 alloy systems. Two simple

methods based on Electron Back-Scattered Di�raction (EBSD) and Focused Ion Beam

(FIB) will be shown to determine the crystallographic orientation of a grain-boundary

plane. Subsequently, it will be highlighted that a combined e�ect of the propensity of

allotriomorphic alpha-phase to establish a Burgers orientation relationship with parent

beta-phase of one of the neighboring grains, and an attempt to produce a low-energy

interface control both crystallographic and morphological aspects of this inherent phase

in titanium alloys.

Fabrication of High Strength Aluminum Alloy Sheets by Twin RollCasting and Rolling Process

22

Hyoung-WooK Kim, Yun-Soo Lee, Min-Seok Kim, and Cha-Yong Lim

Korea Institute of Materials Science, Korea

Light weighting of vehicles has been an important issue to reduce energy consumption

and CO2 emission. Many light metals like aluminum, magnesium have been developed to

replace a steel structure for light weighting of automobile body, but its strength is not

enough to satisfy the needs of manufacturer. In addition, the cost for the light weighting

should be considered. Twin roll casting is well known as a low cost process to make

aluminum thin strip because it can make the strip directly from the melt. In order to

make high strength aluminum strip by twin roll casting, optimum process condition was

developed, and several high strength aluminum strips were fabricated successfully. In this

paper, the characteristics of Al-Mg and Al-Zn-Mg-Cu alloy strip fabricated by twin roll

casting and rolling were investigated and the possibility of the sheets on the automotive

application will be discussed.

Fatigue Behaviors of A Newly Developed ECO-7175-v3 ExtrudedAluminum Alloy

Chinh Vu1, Chien Wern1, Bong-Hwan Kim2, Shae Kwang Kim2, Ho-Joon Choi2, and

Sung Yi1

1Portland State University, OR, USA and 2Korea Institute of Industrial Technology, Korea

In this study, the fatigue characteristics for a new extruded aluminum 7175 with an

experimental composition which uses a magnesium-calcium alloy during the alloying process

instead of the standard pure magnesium is investigated. Specimens of ECO7175v3 were

fabricated and subjected to fatigue life testing, fatigue life data analysis, and observation of

their fracture characteristics through optical microscopy and scanning electron microscopy

(SEM), and metallography to study their grains and surface characteristics. The S-N

curve shows that the fatigue life for the new fabricated ECO7175v3 aluminum can exceed

5x107 cycles with a fatigue strength of approximately 220 MPa or less, about 40% of its

tensile strength.

Synthesis of Copper Nanowire and Eco-friendly Fabrication Methodof Cu-Ag Nanowire

23

Suhyun Lee and Sung Yi


Copper nanowire has been attracted attention with high electrical conductivity and the

combination of �exibility and low cost to replace indium tin oxide (ITO). It is necessary to

synthesize high-quality of copper nanowires and fabricate core-shell structure nanowire to

enhance oxidation resistance of copper nanowires. The objective of this study is to optimize

synthesis of copper nanowire to improve the quality and to develop a facile method using an

eco-friendly chemical to fabricate copper-silver (Cu-Ag) nanowires. Solution-based method

by reducing copper ions to copper atoms is employed to synthesize copper nanowires.

Cu-Ag nanowires are fabricated through a facile method using an eco-friendly chemical,

organic compound A, without electrode and heating. Those are assessed by Scanning

Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Copper

nanowires are synthesized under the various concentration of hydrazine, ethylenediamine

(EDA), sodium hydroxide (NaOH), and copper salt, and various temperatures to optimize

synthesis. By controlling conditions, copper nanowires having a high-quality, which is the

length of longer than 18 um and diameter of 25-45 nm, are obtained. In addition, Cu-Ag

nanowires are fabricated successfully using an eco-friendly material, organic compound A.

A Study of Thermal Energy Storage Systems of Phase ChangeMaterials

Kyung-Eun Min1, So-Jung Lee2, Jun Ki Kim2, and Sung Yi1

1Portland State University, OR, USA and 2Korea Institute of Industrial Technology, Korea

A Thermal Energy Storage (TES) system is an important technological system in providing

energy savings as well as e�cient and optimum energy use. A latent heat storage, one

of the main types of a TES system, is a very e�cient method for storing or releasing

thermal energy due to its high energy storage density at constant temperatures. Phase

Change Materials (PCMs) as called latent heat storage materials can save thermal energy,

and use energy e�ciently. PCMs have widely researched, but the current issues are

lack of accurate and detailed information about thermophysical properties of PCMs to

apply into buildings and inaccurate materials properties measured by existing methodology.

The objective of this study is to develop a methodology and procedure to accurately

determine the thermophysical properties of PCMs. TES systems of PCMs are measured

24

and analyzed by various methods, such as DSC method and heat �ow method. The

developed methodology is designed based on ASTM C1784-14 for measuring the thermal

energy storage properties of PCMs. The thermophysical properties are evaluated by

using a Di�erential Scanning Calorimetry (DSC). The enthalpy changes of the PCMs

are determined by DSC method and heat �ow method. Four di�erent types of Phase

Change Materials (PCMs) are employed to measure the thermophysical properties. In

order to assess the thermal energy storage systems of the PCMs, the thermophysical

properties measured under the dynamic DSC mode are used in this study. The enthalpy

change curves as a function of temperature, which are determined by DSC method and

heat �ow method, are indicated to assess thermal energy storage system of the PCMs.

Moreover, the enthalpy change curves determined by heat �ow method show more precise

results than the curves by DSC method, because various factors lead to a temperature

gradient in the PCM and the heat �ux signal peak being shifted toward high temperatures.

This study shows the developed methodology and procedure and the accurate material

information for the newly developed PCM to analyze the TES systems with much more

precision in the area of the PCMs.

25

List of Posters

Poster Sessions

Development of High-Mg Containing AlMg Wrought Alloys withHigh Strength and High Ductility for Lightweight Purpose of

Transportation Industries

Seong-H. Ha, Young-O. Yoon, Hyun-K. Lim, and Shae K. Kim


AlMg alloys have widely been used in the transportation industries because of their good

combinations of strength, formability, weldability, and corrosion resistance. The yield

strength of AlMg alloys increase with the magnesium content without unduly reducing

ductility. However, magnesium amounts in commercial AlMg alloys have been limited

under 5wt% practically, because of great oxidation tendency of Mg. Recently, a special

Mg mother alloy, called EMMA bearing Al2Ca, with suppressed oxidation tendency has

been developed. The aim of this work is to make wrought AlMg material by replacing

pure Mg by EMMA (so called as ECO-Almag) and to evaluate the microstructures and

mechanical properties of ECO-AlMg alloys containing higher Mg element over 5wt% in

extrusion and rolling processes.

E�ect of Continuous Welding on Microstructure and MechanicalProperties of Angle and T-bar

Jihoon Jang, Changsuk Yoon, Yongjae Lee, Sangik Lee, and Dong-Geun Lee

Sunchon National University, Korea

Section steels produced by welding technology are essential parts for shipbuilding and

o�shore plants production. T-type and H-type section steels were produced by handwork

for secondary processing, which were very hard and di�culty as one of the 3D (Di�cult,

Dirty, Dangerous) activity. Automatic welding technology is strongly demanded and

26

has to show very sound welding properties and high speed welding process, in order to

meet the demand even if the demand exceeds the supply. It is necessary to optimize

welding conditions by controlling parameter (current, voltage, welding speed etc.) to

obtain the desired welding bead shapes and high reliability for microstructural properties

of welded zone is obtained by microstructural evaluation and controlling the internal

defects to satisfy mechanical properties. In this study, HAZ (heat a�ected zone) and weld

defects of the �llet-welded Angle and T-bar parts were investigated by microstructural &

macrostructural analysis, calculation of bead angle, throat and leg length, and observation

of phase transformation to ensure the soundness of AH36 section steel parts, which were

welded by continuous both side welding process. The microstructural evolutions and

mechanical properties of each heat a�ected zone were analyzed and evaluated for the

welding parts according to the di�erent welding order and shape of welding parts.

Heat Transfer Characteristics of Bulkhead Penetration Piece forA-Class Compartment of Ship and O�shore Plant

Chang Yong Song and Jonghwan Park

Mokpo National University, Korea

In order to protect passenger or mariner's lives in the event of a �re and to prevent

large-scale damage accidents, Classi�cation Societies have strengthened the relevant

design rules to prevent �ames from being transmitted from the �ring point to other

compartments. In compartments where �re protection is important, such as A-class

compartment, the airtightness and �re protection design of members that pass through

bulkheads and decks are strictly regulated by the International Maritime Organization's

(IMO) Safety of Life at Sea Convention (SOLAS). In order to verify the suitability of

the �re protection design for such penetration members, the �re test prescribed by the

Maritime Safety Committee (MSC) must be performed, but numerical analyses are need

to be carried out to minimize the time and cost required for the test. In this study, the

transient heat transfer numerical analysis based on the �nite element method was applied

to investigate the heat transfer characteristics of the bulkhead penetration piece for the

A-class compartments. The transient heat transfer analyses were carried out according

to the MSC �re test procedure, and the heat transfer characteristics of the bulkhead

penetration pieces of various materials were reviewed.

27

Fabrication of Plastics/Metal Hybrid Multi-Components using theDSI (die slide injection) molding for Electrical Conductor

Applications

Seok-Jae Ha, Min-Kyu Son, Jun-Young Jang, Young-Bae Ko, and Baeg-Soon Cha


Recently, various manufacturing technologies such as the over-molding process, an insert

injection molding process are capable to produce hybrid plastics and metals. However,

these have disadvantages due to several manufacturing process steps and limitation in the

achievable complexity of the part geometry. Also, the production of the metal component

is characterized by additional expensive and complex procedures like bending, stamping,

drilling etc. The purpose of study, an e�ective approach to produce metal/plastic hybrid

components is to combine the plastics injection molding and the metal die casting to

a new hybrid metal/plastic components process. The integrated metal/plastic hybrid

injection molding uses the established and proven method of multi component technology

as a fundament to combine plastic injection molding with metal die casting into one

integrated process. The new injection molding process is based on a standard injection

molding machine. Additionally, the newly developed metal injection module is applied

to die casting of low melting alloy. The plastics materials and metal are combined in

a specially designed DSI (die slide injection) mold. In a �rst step, the plastic material

preform is molded. The surface of this molded features has a �ne groove. This de�nes

the path in which the low-melting alloy is injected in a second step. The injection of

a liquid melting alloy on the heat sensitive thermoplastic component is possible due to

the low melting point range between 200 degree C and 250 degree C. Therefore, using

the primary forming techniques plastic parts with integrated electrically conductive paths

can be produced in one machine and one injection mold. In this study, the electrical

conductivity, and the ampacity are veri�ed to qualify the new process for the production

of parts used in electronic devices. The electrical conductivity is measured, contacting

both side of the test sample with a constant pressure. The resistivity is measured using a

micro ohmmeter. The speci�c conductivity is subsequently calculated from the resistivity

and the contact surface of the conductor path.

In�uence of Cutting Heat on Machining Titanium Materials byCombining MQL (Minimum Quantity Lubrication) and Cryogenic

Air Spraying

Ki-Hyeok Song, Seok-Jae Ha, and Gil-Sang Yoon

28


In conventional machining, the use of cutting �uid is essential to reduce cutting heat and

to improve machining quality. However, to increase the performance of cutting �uids,

various chemical components have been added. However, these chemical components

during machining have a negative impact on the health of workers and cutting environment.

In current machining, environment-friendly machining is conducted using MQL (minimum

quantity lubrication) or cryogenic air spraying to minimize the harmful e�ects. Recently,

MQL or cryogenic air spraying methods have been used in the machining of titanium

alloy, which is used to manufacture parts of aircrafts and medical devices. Titanium alloy

has a thermal conductivity corresponding to 1/8 of typical steel and 1/2 of stainless

steel. Thus, it is di�cult to dissipate heat when machining; further, cutting temperature

is approximately 600 degree C or higher during dry machining. This leads to cutting

surface degradation and rapidly tool wear. Many studies have been conducted on titanium

alloys machining technology, and among them, there is on MQL, cryogenic air spraying,

and laser assisted machining for the ductile characterization of workpiece. However,

most of studies on machining of titanium are based on the analysis of the machined

surface and tool wear by the reduction of cutting temperature. The cutting temperature

during dry machining of titanium alloy should be measured, along with the temperature

observed during machining when using MQL or cryogenic air spraying, to reduce the

cutting temperature. Therefore, a comparison of these two measurement results, and an

analysis on the low temperature cutting performance will be useful. Therefore, in this

study, low temperature cutting performance was analyzed by measuring the temperature

with thermal couples and pyrometer during machining of titanium alloy as well as during

machining when using MQL, cryogenic air spraying, and a combination of the two methods.

A hybrid injection nozzle was designed.

Alloy design of ECO-Al 7175 Alloys and Analysis of TheirMechanical and Corrosion Properties

Seung-Yoon Yang1;2, Bong-Hwan Kim2, Da-Bin Lee2, Kweon-Hoon Choi2, Nam-Seok

Kim2, Seong-Ho Ha2, Young-Ok Yoon2, Hyun-Kyu Lim2, Shae K. Kim2, and Young-Jig

Kim2

Sungkyungkwan University1, Korea, and Korea Institute of Industrial Technology2, Korea

Al 7xxx series alloys have been used as the major materials for aircraft because of the

highest strength level of all aluminum alloys. For using Al 7xxx alloys as aircraft parts,

29

molten metal quality is considered important and it has been controlled by various methods.

One of the most common causes to lower quality is great oxidation tendency of Mg

element. Recently, Mg mother alloy containing Al2Ca has been used for suppressing

oxidative tendency of Mg element during casting. Al alloys which are casted using Mg

mother alloy containing Al2Ca are named ECO-Al alloys. In this study, ECO-Al 7175

alloys were designed to control their microstructure by controlling content of Cr element.

Billet of ECO 7175 alloys was produced through Direct Chill casting and extruded after

homogenization. Mechanical properties (e.g. Fracture toughness and tensile properties)

and corrosion properties (e.g. SCC resistance) was measured and microstructure was

analyzed through OM, SEM and TEM.

E�ect of Multiple Forging on Microstructure and Tensile Propertyof Al-Mg Alloy Castings Containing High Content of Mg

Seong-Ho Ha, Young-Chul Shin, Young-Ok Yoon, Bong-Hwan Kim, Hyun-Kyu Lim, and

Shae K. Kim


Al-Mg alloys have attracted a signi�cant attention because of superiority in mechanical

properties, corrosion resistance, weldability, and low density. With this promising potential,

the demand for the Al-Mg alloys in the vehicle and aircraft industries has increased. Al-Mg

alloys provide favorable formability, high strength, and high strain hardening. E�ect of

multiple forging on microstructure and tensile property of Al-Mg alloy castings containing

high content of Mg at room temperature was investigated in this study. A multiple

forging was done by the upsetting dies customized in this study to allow continuous strain

accumulations on the alloy workpiece. The forged microstructures demonstrated the

formation and growth of twins and dislocation clusters. The further development of the

twins and dislocation clusters with increasing the forging pass was shown. The cold-forged

specimens exhibited signi�cant increases in strength after the forging, while a trade-o�

relationship between the elongation and strength was observed.

A New Multiforging Test Method for Forgeability Assessment ofAluminum Alloys

Young-Chul Shin, Seong-Ho Ha, Ji-Woon Lee, Dae-Kwan Joung, Ho-joon Choi,

Seung-Mok Yoo

30


In this study, a new multiforging test method is proposed to assess the formability of

aluminum alloys suitable for forging process and to evaluate mechanical properties of

forged parts depending on the strain level. Using a dies with octangular rod shaped cavity

and multiforging process, a certain amount of strain is continuously accumulated on

the workpiece. Finite element (FE) analysis results indicated that the strain is mainly

concentrated in the core and that the shear bands broadened and developed into a form

with an X shape in the longitudinal cross-section after the multiforging. The e�ective

strain in the core in the workpiece linearly increased with increasing number of forging

passes. The longitudinal e�ective strain was distributed consistently throughout the

midsection of the workpiece. Form the forging experiment results using the devised dies,

we observed that the aluminum alloy workpieces were substantially deformed depending

on the multiforging passes. Cracks formed and began to propagate on the both ends of

the workpieces forged with the designed die after �ve passes. Tensile strengths of the

forged specimens showed substantial increases depending on the number of forging passes.

The microstructures of the forged samples showed the formation and growth of twins and

dislocation clusters. Using the devised test method in the study, it is possible to �gure

out forgeability and mechanical properties changes depending on strain level, forming

temperature, and forging speed for aluminum alloy of interest. Especially, through the

development of a map that encompasses all of these results, we expect to be able to

clearly grasp the overall characteristics of the aluminum alloy.

A Study on Adhesive Bonding Behavior for Car Body Assembly ofCFRP-metal Dissimilar Materials

So-Jeong Lee, Da-In Lim, and Jun-Ki Kim


Recently, automobile weight lightening has been researched to improve fuel e�ciency, it

is now highlighted as a central issue in the automobile industry due to increased demands

on reinforced fuel e�ciency and diesel exhaust regulations of internal combustion engine

automobiles and increased mileage of electric automobiles. Various materials such as high

tensile steel, aluminum, magnesium, and �ber reinforced composite materials are applied

in order to secure rigidity and durability along with light-weighting of the body. Because

the conventional welding processes are not suitable for these new materials, new joining

technology, such as adhesive bonding, is required. High performance epoxy adhesives are

31

now used in the construction of car body due to their high adhesion strength, durability

and manufacturing process adaptability. When assembly processing CFRP and metal

multi-materials, due to di�erences in thermal expansion coe�cients, forms of bonded

parts after hardening and residual stress and distortion of structures are a�ected by the

time adhesives are hardened. In this study, CFRP and metal were joined by process

simulation the automobile body part assembly processing in order to assess properties

of multi-material adhesives with di�erent hardening completion times. For each stress

mode of bonded parts, on the bonded parts following the adhesive application conditions

and painting process conditions, X-ray transmission tests and mechanical properties

assessments were done.

The Study about Die and Mold Manufacturing with a Direct EnergyDeposition (DED) Additive Manufacturing Process

Woo Sung Kim, Myung Pyo Hong, Yoon Sun Lee, Min Gyu Lee, and Ji Hyun Sung


The Direct Energy Deposition (DED) process is one of the additive manufacturing

technologies which creates layers by melting workpiece and adding powders in the melting

pool directly. It has the advantage of depositing heterogeneous materials because it

can be layered directly on existing shapes, and the advantage of reducing the cost of

deposition process by hybrid process which can be laminated only on necessary parts after

machining process. With these advantages, the DED process can be used to the die

and mold industries such as injection mold, trimming dies and hot stamping dies. The

DED process can use the various commercial mold and die powders materials such as

P20, P21, SUS420, H13 and D2. The main objective of this study is to provide various

characteristics of the parts made by a DED process and prove the performance of the AM

parts of dies and molds which are fabricated by the hybrid method of a DED process.

32

Partner Institutions and Sponsors

Partner Institute

33

Sponsors

34

OSG is a leading manufacturer of high quality taps, end mills, drills, and indexable cutting tools with operations spanning across the globe. OSG’s extensive line of high technology cutting tools features exclusive metallurgy, cutting geometries and proprietary surface treatments. OSG is committed to contributing to the advance-ment of the manufacturing industries by shaping our customers’ dreams into reality.

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