KRISHNA INSTITUTE OF ENGINEERING AND

TECHNOLOGY, GHAZIABAD

Seminar on

“ADDITIVE MANUFACTURING”

Submitted by: Submitted to:

Harsh Kumar Mr. Arunesh Chandra

Roll No.- 1202940074 ME Dept.

Sec. A , ME(3rd year)

CONTENTS

1. History

2. Introduction

3. Additive manufacturing techniques

4. Advantages

5. Disadvantages

6. Applications

7. Scope of additive manufacturing

8. References

HISTORY

The technology for printing physical 3D objects from digital data was first

developed by Charles Hull in 1984. He named the technique stereolithography

and obtained a patent for the technique in 1986. The same year, he founded 3D

Systems and developed the first commercial 3D Printing machine.

AM processes for metal sintering or melting (such as selective laser

sintering, direct metal laser sintering, and selective laser melting) usually went

by their own individual names in the 1980s and 1990s. Nearly all metalworking

production at the time was by casting, fabrication, stamping, and machining; even

though plenty of automation was applied to those technologies (such as by robot

welding and CNC), the idea of a tool or head moving through a 3D work envelope

transforming a mass of raw material into a desired shape layer by layer was

associated by most people only with processes that removed metal (rather than

adding it), such as CNC milling, CNC EDM, and many others.

Charles Hull

INTRODUCTION

The process of joining materials to make objects from 3D model data,

usually layer upon layer, as opposed to subtractive manufacturing methodologies

is known as Additive Manufacturing.

Synonyms: additive fabrication, additive processes, additive techniques,

additive layer manufacturing, layer manufacturing and freeform fabrication.

As an Enabling Technology AM is used in a broad spectrum of manufacturing.

Illustration of this process

Steps For Additive Manufacturing

1. Generate a 3D model

Draw a 3D model of product on any software such as CAD,

Solid Works etc.

2. Generation of STL(Stereolithography) file

The STL (stereo lithography) file format is supported by many

other software packages; it is widely used for rapid prototyping and computer-

aided manufacturing (CAM). STL files describe only the surface geometry of

a three dimensional object without any representation of color, texture or other

common CAD model attributes.

*An STL file describes a raw unstructured triangulated surface by the unit

normal and vertices (ordered by the right-hand rule) of the triangles using a

three-dimensional Cartesian coordinate system.

Fig. STL File

3. Software slices the 3D model into thin slices

Fig. Slicing of 3D model

Now computer scans this area and give instructions to printer or

machine to procced for further operations.

4. Machine builds it layer by layer

5. Cleanup and post curing

6. Surface finishing

Additive Manufacturing technologies and their base materials :

1. 3D Printing (3DP): Various materials, including resins

2. 3D Ceramic Printing: Various clay and ceramic materials

3. Selective laser sintering (SLS): Thermoplastics, metals, sand and glass

4. Fused Deposition Modeling (FDM): Thermoplastics

5. Stereolithography (SL): Photopolymer

6. Laminated object manufacturing(LOM): Laminate sheets, often paper, and

glue

7. Electron Beam Melting (EBM): Titanium alloys

Machine Cost Response Time Material Application

Fused Deposition

Modeler 1600 (FDM)

$10/hr 2 weeks ABS or Casting

Wax

Strong Parts

Casting Patterns

Laminated Object

Manufacturing

(LOM)

$18/hr 1 week Paper (wood-

like)

Larger Parts

Concept Models

Sanders Model

Maker 2 (Jet)

$3.30/hr 5 weeks Wax Casting Pattern

Selective Laser

Sintering 2000 (SLS)

$44/hr 1 week Polycarbonate

TrueForm

SandForm

light: 100%; margin:

0">Casting Patterns

Concept Models

Stereolithography

250 (SLA)

$33/hr 2 weeks Epoxy Resin

(Translucent)

Thin walls

Durable Models

Z402 3-D Modeller

(Jet)

$27.50/hr 1 week Starch/Wax Concept Models

1. Selective laser sintering (SLS)

This is an additive manufacturing technique that uses a high power laser

to fuse small particles of plastic, metal, ceramic or glass powder into the

desired 3-D shape.

The laser selectively fuses the material by scanning cross sections

generated from a 3-D digital description of the part, for example a CAD file.

It can be used for both thermoplastics and metal. Powder is fed into a

continuous layer. Laser is used to fuse/sinter powder particles layer-by-layer.

Produces functional parts. Layer thickness 0.004” or less.

Fig. SLS Manufacturing Technique

SLS Samples:

A Basket A complex model

2. Electronic beam melting (EBM)

This solid freeform fabrication method produces fully dense meta, parts

directly from metal powder. The EMB machine reads data from a 3-D CAD

model and lays down successive layers of powdered material. The layers are

melted together with the help of a computer controlled electron beam. This

way it builds up the parts. The process takes place under a vacuum, which

makes it suited to manufacture parts made out of reactive materials

• Dispensed metal powder in layers

• Cross-section molten in a high vacuum with a focused electron beam

• Process repeated until part is completed

• Stainless steel, Titanium, Tungsten parts

• Ideal for medical implants and injection molds

• Still very expensive process

Fig. EBM manufacturing technique

EBM samples:

3. 3D Printing(3DP)

Fig. 3D Printing technology

• Layer of powder is first spread across build area

• Inkjet-like printing of binder over the part cross-section

• Repetition of the process with the next layer

• Can produce multi-colored parts

• Useful only for presentation media

• Lowest resolution of all techniques

• Market Leader: Z-Corp

3D Printing samples:

Piston with cam-follower Morongo Casino, Palm Springs, Model

4. Fused deposition modelling (FDM)

FDM works on an "additive" principle by laying down material in

layers. A plastic filament or metal wire is unwound from a coil and supplies

material to an extrusion nozzle. The nozzle is heated to melt the material

and can be moved horizontally and vertically. The part, or model, is

produced by extruding mall beads of thermoplastic material to form layers

and the material hardens immediately after extrusion from the nozzle.

• Extruder on a cartesian robot

• Extrudes thermoplast polymers “spaghetti”

• Moderately fast and inexpensive

• Stratasys is the market leader

• Functional parts, ABS and nylon

• Best choice for mechanical engineers and product developers

• Can be used for direct digital manufacturing

• Systems starting from $14,000

Fig. FDM manufacturing technique

FDM samples

Internal gear

A Model

5. Laminated Object Modeling (LOM)

In some printers, paper can be used as the build material, resulting in a

lower cost to print. During the 1990s some companies marketed printers that cut

cross sections out of special adhesive coated paper using a carbon dioxide laser

and then laminated them together. In 2005 Mcor Technologies Ltd developed a

different process using ordinary sheets of office paper, a tungsten carbide blade

to cut the shape, and selective deposition of adhesive and pressure to bond the

prototype. There are also a number of companies selling printers that print

laminated objects using thin plastic and metal sheets.

• Object made by deposition and cutting of layers of tapes

• Introduced in 1991 by Helisys Inc of Torrance.

• Cubic and Helisys offer this technology

• Slow, sharp edges

• Research on composites prepregnated moldless manufacturing

• Inexpensive depending on accuracy, large scale models possible

• Slow and inaccurate (knives vs lasers)

Fig. LOM manufacturing technique

LOM samples

Fig. 1- parts made up of plastics

2-model made up of paper

3-model made up of paper

6. Stereolithography (SLA)

Stereolithography is a process for creating three-dimensional objects

using a computer-controlled laser to build the required structure, layer by layer.

It does this by using a resin known as liquid photopolymer that hardens when in

contact with the air.

• Patented in 1986

• 3D System is the market leader

• Highest resolution and smoothness

• UV Laser beam cure cross-sections of parts in a liquid batch of

photoreactive resin

• Subvariants: DLP entire layer projection

Fig. SLA manufacturing technique

SLA samples

An aeroplane model Nokia Lumia 820 Case

ADVANTAGES OF ADDITIVE MANUFACTURING

Adopted 3D printing as a way to increase innovation.

Mechanical properties of products are more as compared to that which are

made by conventional process.

Reduce costs and speed up the process.

3D models of buildings can be easily created and edited as plans develop

something that used to take a significant amount of time to make.

Freedom of creation of more complex geometries.

More Complex Geometries

Internal Features & Structures

Parts Consolidation

Enables business models used for 2D printing, such as for photographs, to

be applied to physical components

Fig. 2D Printing

The unattainable triangle of speed, price and quality.

Eliminates drivers to concentrate production

“Design Anywhere / Manufacture Anywhere” is now possible

Manufacture at the point of need rather than at lowest labor

location

Changing “Just-in-Time Delivery” to “Manufactured-on-

Location Just-in-Time”

DISADVANTAGES OF ADDITIVE MANUFACTURING

Construction of large parts is not possible but research are going to make

large machines.

Machine cost is high

The current slow print speed of 3D printers limits their use for mass

production.

APPLICATIONS OF ADDITIVE MANUFACTURING

Medical procedures

Advances in research

Product prototyping

Historic Preservation

Architectural Engineering Construction

Advanced Manufacturing

Food Industries

Automotive

Accessories

1. Architectural Engineering Construction

Morongo Casino, Palm Springs, Model

Morongo Casino, Palm Springs

2. Automotive

Fig. Engine model Fig. Tyre rim

3. Medical procedures

Bespoke Entire titanium jaw

SCOPE OF ADDITIVE MANUFACTURING

First ever 3-D printed car.

Urbee is the first prototype car ever to have its entire body 3D printed with

an additive process. All exterior components, including the glass panel

prototypes, were created using Dimension 3D Printers and Fortus 3D

Production Systems at Stratasys' digital manufacturing service.

Fig. URBEE- First 3D printed car

3-D printed Buildings?

Architect Enrico Dini is planning to build the first ever 3-D printed

building with the help of fellow architects.

REFERENCES

Professor John Hart(ajhart@mit.edu), Massachusetts Institute Of

Technology(MIT)

Wright, Paul K. (2001). 21st Century manufacturing. New Jersey:

Prentice-Hall Inc.

Lipson, Hod, Francis C. Moon, Jimmy Hai, and Carlo Paventi. (2007)

"3D-Printing the History of Mechanisms." Journal of Science.