process optimization and properties of select non … · 5/13/2008 · sintered test bar before...

PROCESS OPTIMIZATION AND PROPERTIES OF SELECT NON-FERROUS MATERIALS USING HIGH PRESSURE COMBUSTION DRIVEN POWDER

COMPACTION

Karthik Nagarathnam, Donald Trostle, and Dennis Massey UTRON Inc (www.utroninc.com) 8506 Wellington Road, Suite 200

Manassas, VA 20109

Paper Presented at the 2008 International Conference on Tungsten, Refractory & Hardmaterials VII, Washington D.C., USA, June 8-12, 2008

Abstract The materials processing and properties of copper, and select refractory materials such as tungsten, molybdenum, TZM and niobium compacted using 300 Ton Combustion Driven Compaction Press are presented. The process advantages of higher pressure CDC compaction (e.g., up to 150 tsi) include: much higher part densities in green and sintered conditions, near net shaping ability, less part shrinkages and improved microstructural and materials behavior. Efforts to optimize the process conditions together with effects on geometrical, physical, and microstructures will be discussed and technological advantages of higher pressure consolidation for scientific advancement and commercial applications will be presented. Potential commercial applications of CDC technology include RF accelerator subsystem accessories, laser optical mirror substrates/heat sinks, x-ray targets, high performance valves, rocket motor components, high temperature parts and biomedical implants. The produced parts were of near net shape or net shape quality at compaction pressures up to 150 tsi which revealed higher part densities and improved microstructural and properties than attainable by conventional P/M techniques. Introduction

Microwave components and accessories for accelerator applications (e.g., couplers, waveguides, RF windows, plates, flanges, and vacuum seals) often require demanding properties, in addition to reliable performance, cost-effectiveness, and tight tolerances for geometry/shape, dimensions, surface finishes, leak rates, RF voltage hold-off, and surface conductivity. The popular candidate materials for such applications include OFHC copper,[20-24, 27], niobium[14-15], aluminum, magnesium diboride [25] and Nb3Sn or (Nb,Ta)3Sn. [1-6] Refractory materials such as W, Mo, and Nb are useful for various high temperature applications. Examples include advanced superconducting cryogenic components (e.g. Nb in superconducting accelerator structures), optical mirror substrates/heat sinks (e.g., Mo), x-ray targets (e.g., W), erosion resistant high temperature electrodes/ignitor components (W, Mo or Re based materials), alternative to Tantalum (e.g., Nb) in capacitors, and high performance fuel cell electrodes. Traditional manufacturing processes

[7-12, 14-15, 16-29, 38] such as casting, forging, PIM,

electroforming and even rapid prototyping techniques such as DMD (Direct Metal Deposition) or LENS (Laser Engineered Net Shaping)

have limitations in terms of produced part quality,

fabrication of difficult to-weld and crack-sensitive dissimilar materials (e.g., Cu/stainless steel or ceramics), surface finishes (typically few microns or higher of average roughness) and often require post-machining costs which are economically not attractive for the manufacturing of large batches of identical components. UTRON’s high pressure Combustion Driven Compaction has emerged as a modern manufacturing method to fabricate rapidly near net or net shape high density Powder Metallurgy (P/M) components as a means of economical and competitive

Powder

-

Gas Inlet Electric Igniter

Combustible Gas Mixture

Die

Ram

Fig. 1 Schematic of CDC Device

manufacturing. Powder metallurgy (P/M) [7, 12, 26, 29] has been used for many years for making near-net-shape metal and composite parts for use in many applications

UTRON is developing a modern and competitive P/M compaction technology called Combustion Driven Compaction-CDC [ 13, 30, 31, 34-37, 39-42] and with much higher controllable compaction pressure loading profiles that are tailored to fabricate similar as well as dissimilar bulk materials with improved part density, means to produce micro/nano powder compacts, better microstructures, chemical homogeneity, near isotropic mechanical properties, and improved mechanical/electrical/superconducting properties allowing new applications in energy, defense and commercial applications. [35-37, 41, 42]

Background of The CDC Process [13, 30, 31, 34-37, 39-42]

Combustion Driven Compaction (CDC) utilizes the controlled release of energy from combustion of natural gas and air to compact powders. In operation the following steps occur: 1) Fill chamber to high pressure with a mixture of natural gas and air; 2) As the chamber is being filled the piston or ram is allowed to move down pre-compressing and removing entrapped air from the powder; 3) The gas supply is closed and an ignition stimulus is applied causing the pressure in the chamber to rise dramatically, further compressing the metal powder to its final net shape. The basic process is shown in Fig. 1.

The CDC process utilizes the direct

conversion of chemical energy to produce compaction.. In addition, the process inherently includes a pre-compaction step preparing the powder for the final compaction load. The CDC process can provide standard or very high compaction tonnages resulting in very high-density parts with improved mechanical properties. In addition to the unique loading sequence and high tonnage the process occurs over a relatively short time frame (a few hundred milliseconds). (Fig. 6) A CDC press is compact and uncomplicated. A 300-ton rated CDC based press is more compact (Fig. 2). When the fill gas is ignited the ram rapidly presses down but without slamming into the tooling or powder. In other words the process although fast and powerful, is smooth and continuous. The CDC process routinely operates at compaction loads of 2069 MPa (150-Tsi). This is in sharp contrast to conventional compaction processes, which generally are limited to 690 MPA (50-Tsi).

CDC Press Scaling As previously mentioned, since the CDC press directly converts chemical energy into

compaction energy it is very energy efficient and capable of producing enormous compaction loads. To date several presses of increasing size (Fig. 2) have been constructed (e.g., 300, 400 and1000 Ton) and operated and more recently an automated 400 Ton production press is under final stages of operation at UTRON. It is possible then to scale a CDC press to very high tonnages without increasing the size of the press itself dramatically.

Fig. 2 300 Ton (left side) and 1000 Ton (right side) CDC Press [41, 42]

Properties of CDC Produced Materials The UTRON’s CDC process operates at compaction pressure loads of 15 to 150-tsi

(conventional P/M pressing by mechanical or hydraulic methods is limited to 50-55 tsi). It is well known that controlled higher compaction pressures generally make a large difference in the final quality of the compacted part, both in the green (unsintered state) and in the sintered state. Another benefit of high part density is minimal dimensional change (shrinkage) after sintering. The CDC optimized high density P/M parts (Figs. 3-5) have also reveled exceptional mechanical/toughness properties, ability to press micro, nano and composite powder materials to yield much higher pressed/sintered densities than possible by conventional P/M methods including castings, improved toughness and high temperature strength/ductilities.

Additional Properties of CDC Processed Materials

100 (green)0.16958.718150Copper

200 (Green)0.16987.537150

Austenitic Stainless

85 -100 (Sintered)0.19367.59154

Low CarbonSteel

39 - 47 (Green & Sintered)

0.2-0.62.63252Al-Mg Alloys

Hardness (kg/mm2)

Roughness (microns)

Density (g/cc)

Load (tsi)

Material

5Powder10Casting15Extrusion

10-25Forming20-25Forging10-60Machining

% ScrapProcess

Fig. 3 a) % Scrap vs Manufacturing Process, CDC Copper & Stainless Steel Rings and

Select Material Properties b) Examples of Variety of Materials & Geometries (Single layer, multi-layered) Successfully Fabricated by CDC Process in Near/Net Shape Finish Qualities [35-37, 39-42]

Stre

ngth

- M

Pa

Stre

ngth

- M

Pa

1 6

8 3

S tand a rd C D C

Gre

en D

ensi

ty (g

/cm

3 )

7 .0 0

S tan da rd C D C

7.76

C D CS tan da rd

262

345

Per

cent

Elo

ngat

ion

S tan da rd C D C

7

30

All samples sintered in dissociated ammonia at 1121 oC (2050 oF) for 30 minutes.

LegendAs Pressed After Sintering

Standard vs. CDC Compaction

F-0000 powder at 483 MPa (35 Tsi) vs. CDC compaction at 1931 MPa (140 Tsi)

Sintered test bar before (left) and after (right) pull test. Note exceptional elongation of bar at right.

Fig. 4 a) Property Improvement of CDC Compacted Ferrous Alloy Samples vs Standard P/M Part and b) Example of Complex Geometry Parts for Next Generation Linear Collider [20-24, 28, 39-42] Applications

Fig. 5 CDC Fabricated a) Ferrous Aerospace-Pyrowear 53 Equivalent Steel Gears After Pressing/Sintering as well as b) c) Multi-Layer Functional Gradient Materials (e.g., copper/400 series martensitic stainless steels)[42] and d) CDC Copper and Molybdenum Mirror Substrates with 98.8 % and 98.3% reflectivities at several hundred (e.g., 107 kW/cm2) cw-CO2 laser intensities [41, 42] The low % of scrap metals (Fig.3) in P/M process compared to other manufacturing processes is unique. Select results of density, surface roughness and hardness of CDC samples of Al-Mg, Steel, Stainless Steel and Copper reveal higher density, smoother surface finish and stronger materials properties. The superior surface quality of CDC copper and stainless steels is evident as well. Figs. 3-5 highlight the variety of materials including nanomaterials and geometries (single layer, multi-layered structures) that can be compacted using CDC process. The high density parts so far successfully CDC compacted and processed include a spectrum of ferrous, non-ferrous, ceramic and composite materials including micro, nano and composites. Figure 4 shows additional evidence of material’s property enhancement (e.g., CDC ferrous material) such as density, strengths and % elongation of CDC samples as compared to those made by traditional powder metallurgy methods as well as complex shapes (e.g., NLC Copper disks) that can be processed. Experimental Conditions, Results and Discussions [41, 42] Experimental Conditions:

• CDC Compaction Experiments: – 300 and 1000 Ton CDC Presses ( – CDC compaction pressures Up to 150 tsi – Powder Materials Compacted Copper (Tables 1-2, Table 9, Figs. 12, 13),

Niobium (Fig. 16, Table 11), Tungsten (Table 3, Table 7, Fig. 14), Molybdenum (Table 4), Mo-Cu (Table 6) and TZM (Table 5) (Table 10 for the Green and Sintered Data for several refractory materials)

– CDC Loading Profiles indicating milliseconds of pressing time (Fig. 6)

• Suitable Sintering Cycles after CDC Pressing at Various Temperatures to evaluate the materials behavior and microstructures and properties

• Samples Geometries: – Dogbones (3.5 inch long) and Cylinders (1 inch diameter; 0.5 inch thickness); 0.5

inch diameter (Using 300 Ton Press) – 2 inch diameter part (Using 1000 Ton Press) (Fig. 16) – NLC Copper Disks (complex shaped copper parts) (Fig. 12)

• CDC Refractory Sample Green and Sintered Properties (Table 10; Tables 4-8) • Microhardness data of CDC compacted and sintered refractory materials (Table 8) • Machinability Studies of CDC Copper Disks 1 inch Diameter (Fig. 13) • Microstructures of CDC Processed Non-Ferrous Refractory Samples (Figs. 7-10, 14) • CDC Process Optimized Results for NLC Copper Disks (Figs.11 and 12), X-Ray Target

(Figs. 14 and 15) and Laser Optical Mirror Substrates (Fig. 5d) CDC Refractory metal samples

Physical measurements and sintering conditions for all of the CDC refractory metal samples are shown in Tables 4 through 7. Figs. 7 to 9 show the sintered refractory sample microstructures as a function of sintering conditions. These fine grained microstructures indicated the advantages of CDC compaction method and ability to press powder materials of relatively finer sizes could be the cause of the observed finer grain size compared to those reported for conventionally annealed and wrought materials[9].

There is also a marked increase in density, from 9.42 to 9.97, between these two samples

as would be expected during sintering. Pure Molybdenum typically has a density of 10.22g/cc [38]. Grain boundaries and contrast were enhanced by suitable etching. Increasing the sintering temperature from 1800oC to 2100oC increases the rate of diffusion, thereby increasing grain size. Density is also increased when sintered at a higher temperature. The hardness for sintered samples ranged from 159.3 to 174.6kg/mm2. The average hardness measurement for a Vickers calibration block of reported hardness 978 kg/mm2 at 200gm load F was 957.952 kg/mm2. Little significant difference in hardness was observed between the samples sintered at 1800oC and 2100oC; however, those samples were softer than the green molybdenum samples. This softening during sintering is equivalent to the softening of a cold worked structure during annealing. All hardness measurements were substantially lower than the 230 kg/mm2 Vickers Hardness reported for annealed molybdenum [38]. In some sintered copper parts, the Rockwell hardness was ~40 Rb. Fig. 8 reveal the sintered TZM microstructures. Increasing the sintering temperature from 1800oC to 2100oC increases the grain size among the sintered TZM disks. The TZM disks have larger grains than the equivalent disks of unalloyed Molybdenum. The sintered samples are significantly denser (9.8 to 9.89g/cc) than the green samples (9.25 to 9.35g/cc). The TZM disks have slightly lower densities than the molybdenum disks. The TZM disks were found to be harder than the molybdenum disks as seen in Table 8. Again, the hardness of the disks decreased with sintering. Among these samples, there does not appear to be a significant difference in hardness caused by increasing the sintering temperature from 1800oC to 2100oC. The hardness of the sintered samples ranged from 167.5 to 180.6 kg/mm2.

Molybdenum copper composite samples (e.g., Sample 855) showed a density range of

8.73 to 8.8g/cc for green parts and a density of approximately 9.14g/cc for sintered parts. This shows a significant effect caused by sintering at 1150oC. The hardness of the green Mo-Cu samples ranged from130.9 to 175.1kg/mm2. The samples with visually higher copper concentrations measured lower hardness than the samples with less copper. Fig,. 9 shows the sintered microstructures of tungsten (Sample # 848) at 1800oC. Sintering of the Tungsten samples increases the density by approximately 2g/cc from the green state. The densities of the group E

disks decreased when the sintering temperature was changed from 1800oC to 2100oC. The group F disks were more dense than group E and showed an increase in density when the sintering temperature was increased. The maximum density for a tungsten disk was 94.1% dense compared to pure tungsten [38]. The hardness of the green tungsten samples is reported in Table 8. These samples ranged in hardness from 374.7 to 392.9kg/mm2 on the Vickers scale. This is harder than the published 310kg/mm2 as would be expected in a cold worked part. Sintering the Tungsten disks decreased the hardness to between 352.2 and 368.2kg/mm2. This is still harder than the published value [38]. CDC copper disks and NLC Copper Disks

Figs. 10 and 11 show select microstructures of sintered CDC copper disk and NLC complex shaped copper disks. This shows clear grain structure and visible twinning among grains. Table 9 indicates the grain sizes of CDC copper. Both electrical conductivity and density properties increase when the compaction pressure is increased from 50tsi to 100tsi. Increasing the CDC pressing load is accompanied by an increase in conductivity up to 250 tons where the conductivity is 94.85%IACS. Increasing sintering time also increases conductivity. Changing the sintering temperature from 875oC to 1000oC, again, has the largest effect on the conductivity of the NLC copper disks. Weight loss is les than 0.7% for all disks. Increasing the time for diffusion by lengthening the sintering time also increases the grain size. Increasing the temperature from 875oC to 1000oC is accompanied by an increase in grain size. Increases in grain size are seen concurrently with increases in conductivity due, in part, to the reduction in the number of grain boundaries and the resistive component that they contribute to the overall resistance. Fig 11 shows an NLC Copper disk pressed at 175 tons and sintered at 875oC for one hour. These micrographs indicate that the microstructure is consistent and finer.

Table 1. CDC Copper Disks (1 inch Dia) Using Powders with Admixed Lube

Sample #: Description: CDC

Pressure (tsi)

Green Density (g/cc)

% of Theoretical

Density

OD (in)

Avg. Thickness

(in)

760 II-E150-CS#1 161.5 8.3919 93.66 1.0053 0.5030

761 II-E150-CS#2 153.9 8.3932 93.67 1.0045 0.5040

762 II-E150-CS#3 153.4 8.3975 93.72 1.0050 0.4985

Powder Specification: Cu 5058; Acupowder 185E Cu with Admixed Lubricant

Die Wall Lubrication: None

Table 2 CDC Copper Disks Using Dry Copper Powders


Pressure (tsi)


% of Theoretical

Density

OD (in)

Avg. Thickness

(in)

763 II-F150-CS#1 152.9 8.7801 97.99 1.0030 0.4830

764 II-F150-CS#2 155.1 8.7856 98.05 1.0030 0.4830

Powder Specification: Cu 185-E; Acupowder Lot#1187

Die Wall Lubrication:

Table 3. CDC Tungsten Disks


Pressure (tsi)


% of Theoretical

Density

OD (in)

Avg. Thickness

(in)

780 II-A150-.5cs#1 164.4 16.8595 87.35 0.5016 0.0975

781 II-A150-.5cs#2 166.7 16.9655 87.90 0.5020 0.0965

782 II-A150-.5cs#3 172.2 17.1245 88.73 0.5018 0.0955

783 II-A150-.5cs#4 169.4 16.9911 88.04 0.5020 0.0965

784 II-A150-.5cs#5 171.9 17.0218 88.20 0.5015 0.0965

785 II-A150-.5cs#6 170.9 17.0026 88.10 0.5015 0.0965

786 II-A150-.5cs#7 169.2 16.9418 87.78 0.5015 0.0967

787 II-A150-.5cs#8 173.0 17.0924 88.56 0.5020 0.0960

788 II-A150-.5cs#9 173.6 16.9436 87.79 0.5015 0.0970

789 II-A150-.5cs#10 178.3 17.0422 88.30 0.5020 0.0965

790 II-A150-.5cs#11 172.6 16.9404 87.77 0.5015 0.0970

Fig. 6 Typical CDC Loading Profile at 150 tsi

Table 4. Physical Properties and Sintering Temperatures for CDC Molybdenum Disks

Disk ID Group Weight (g) Diameter (in)

Thickness (in)

Density (g/cc)

Sintering Temp. (oC)

Weight (g)

Diameter (in) Thickness (in) Density

(g/cc)813 A 3.119 0.502 0.103 9.330 1800 3.105 0.492 0.100 9.96814 A 3.102 0.502 0.103 9.330 2100 3.088 0.491 0.100 9.95815 A 3.114 0.502 0.103 9.320816 A 3.117 0.502 0.102 9.420817 A 3.117 0.502 0.102 9.420 2100 3.104 0.491 0.100 10.00818 A 3.121 0.502 0.103 9.390 1800 3.108 0.492 0.101 9.90819 B 3.076 0.503 0.101 9.350 1800 3.051 0.493 0.098 9.97820 B 3.102 0.503 0.102 9.340 2100 3.091 0.491 0.099 10.06821 B 3.093 0.503 0.101 9.400822 B 3.098 0.503 0.101 9.420823 B 4.107 0.503 0.134 9.410 2100 4.093 0.492 0.131 10.03824 B 3.097 0.503 0.101 9.420 1800 3.060 0.493 0.099 9.88

Green Measurements Sintered Measurements

Table 5. Physical Properties and Sintering Conditions for CDC TZM Disks


Thickness (in)

Density (g/cc)


Weight (g)


(g/cc)825 C 3.121 0.502 0.103 9.340 1800 3.114 0.493 0.102 9.81826 C 3.107 0.502 0.103 9.340 2100 3.095 0.492 0.101 9.83827 C 3.122 0.502 0.104 9.300828 C 3.118 0.502 0.103 9.330829 C 3.123 0.502 0.103 9.350 2100 3.111 0.492 0.101 9.89830 C 3.123 0.502 0.103 9.350 1800 3.117 0.493 0.102 9.84831 D 3.088 0.503 0.102 9.290 1800 3.081 0.493 0.100 9.85832 D 3.085 0.503 0.102 9.290 2100 3.072 0.493 0.099 9.92833 D 3.096 0.503 0.102 9.320834 D 3.109 0.503 0.103 9.270835 D 3.105 0.503 0.103 9.250 2100 3.077 0.494 0.100 9.80836 D 3.108 0.503 0.103 9.260 1800 3.103 0.493 0.101 9.89


Table 6 Physical Properties & Sintering Conditions for CDC Moly-Copper Composite Disks


Thickness (in)

Density (g/cc)


Weight (g)


(g/cc)851 G 2.997 0.502 0.105 8.800 1150 2.968 0.495 0.103 9.138852 G 2.994 0.502 0.105 8.790853 G 2.997 0.502 0.105 8.840854 G 3.001 0.502 0.106 8.730855 G 2.999 0.502 0.105 8.850856 G 2.888 0.502 0.105 8.800 1150 2.970 0.495 0.103 9.142


P

Table 7. Physical Properties and Sintering Temperatures for CDC Tungsten Disks


Thickness (in)

Density (g/cc)


Weight (g)


(g/cc)837 E 5.373 0.503 0.112 14.730 1800 5.354 0.491 0.104 16.67838 E 4.990 0.503 0.105 14.590 2100 4.973 0.490 0.098 16.42839 E 4.985 0.503 0.105 14.580840 E 4.988 0.503 0.104 14.730841 E 4.985 0.503 0.105 14.580 2100 4.969 0.491 0.097 16.54842 E 4.978 0.503 0.104 14.700 1800 4.961 0.490 0.096 16.72843 F 5.293 0.502 0.097 16.820 1800 5.288 0.487 0.097 17.86844 F 5.421 0.502 0.101 16.630 2100 5.416 0.484 0.099 18.14845 F 5.422 0.502 0.100 16.710846 F 5.437 0.502 0.100 16.760847 F 5.428 0.502 0.101 16.650 2100 5.423 0.484 0.099 18.17848 F 5.436 0.502 0.100 16.760 1800 5.431 0.487 0.102 17.53


Table 8. Vickers Hardness of Sintered CDC Refractory Metal Disks

Disk IDHardness (kg/mm2)

815 174.6816 173.4819 159.3821 169.8822 171.4823 167.4824 166.6

Molybdenum


839 392.9840 391.8843 368.2845 374.7846 382.8848 352.2

Tungsten


852 130.9853 175.1854 149.5855 161.5

Molybdenum-Copper


828 180.6831 167.5833 180.4835 167.7836 175.3

TZM

Table 9. Grain Sizes of CDC One Inch Copper Cylinders (Groups E-G and Composites)

Disk ID D1 (µm) D2 (µm) D3 (µm) D4 (µm)11-D25-2 78.89 42.22 29.63 12.5911-E150-1 80.00 47.04 19.63 16.3011-E150-2 48.15 17.78 9.63 4.4411-E150-3 84.44 60.00 27.41 17.0411-F150-1 34.81 32.59 6.67 4.8111-F150-2 20.37 17.04 5.19 3.7011-F150-3 61.85 27.04 25.93 13.3311-G50-2 48.89 31.85 31.85 23.7011-G150-2 82.96 75.56Composite811 57.41 42.96 15.56 10.00812 105.19 85.93 70.37 28.15

Large Small

Fig. 7a and b: Sample 819, Molybdenum sintered at 1800oC and 2100 deg C (#823)

Fig. 8a and b. Sample 836, TZM sintered at

1800oC and 2100oC Sample 835

Figure 9. Sample 848, Tungsten sintered at 1800oC

Figs. 10 a and b. One Inch Copper Cylinder, Sample II-F-150-3 and NLC Copper Disk 874, Top

Figs. 11. UTRON’s NLC Copper Disks (Pressed @ Load of 175 tons & Fig. 12 Optimally Sintered CDC Copper Samples’s Excellent Machinability (Using Carbide Turning Tool) [41]

CDC Refractory Metals for X-ray Targets and Laser Mirror Substrate Applications We have made efforts to get excellent x-ray tube anode performance at 70 kV using CDC

processed refractory tungsten and molybdenum disks. CDC W targets# 782, #785 and CDC Mo-targets of #817 and #820 were subjected to 40 hours of testing for each tube. Operating levels were set at 70kV, 2 ma. These static x-ray tubes with CDC tungsten target were tested and evaluated to pass more than 7000 exposure runs using their standard qualification test at a leading manufacturer of dental bite-wing x-ray system. These results (Figs. 14-15) indicate that the commercialization potential to densify difficult-to-press refractory materials such as tungsten and Moly or TZM using CDC for x-ray applications in biomedical, homeland security and numerous other quality control inspection applications. UTRON’s CDC Compacted Tungsten (W) targets were assembled in 6 x-ray tubes. The serial numbers are T780, T781, T782, T783, T784 and T785.(Fig. 14) Serial numbers correspond to UTRON Sample Numbers 780-785, respectively. All these tubes correspond to Brand X-Ray Model BX-4P and is in a mass production scale for a dental x-ray tube commercial use. Tubes were characterized at 70 kV accelerating potential level. Filament current input and anode current measurements were taken from 1 to 5 mA at 0.1 mA increments. Similar data was also recorded for standard x-ray targets. The materials thus far perform in an x-ray environment. The materials have shown very good material stability in the way of vacuum environment performance. Targets also show no visible signs of cracking or other degradation when subjected to light duty. Focal spot characteristics are similar to those of standard BX-4 units and within NEMA focal spotting tolerances,”. Fig. 5d shows the results of CDC Pressed and Processed Laser Optical Mirror Substrates of Copper and Molybdenum.

Fig 14. CDC Net Shape W-Targets in X-Ray Tubes and Microstructures (2000 C, 1 hr) [41]

Fig. 15 Sintered Properties and X-Ray Tube Characteristics with CDC Net Shape Tungsten Anodes

Target Comparison Compacted and Non-Compacted Targets

3.23.33.43.53.63.73.83.9

4

1.00

1.40

1.80

2.20

2.60

3.00

3.40

3.80

4.20

4.60

5.00

Tube Emission (mA)

Fila

men

t Cur

rent

(Am

pere

s)

T22B2T28B8T28B3780781782783784785T28B0

Results of UTRON's Hydrogen Sintered CDC Tungsten Disks and Wrought Tungsten

(Sintering Temperature: 2000 deg C; Time: 1 hr; Powder Size: 4 to 6 microns)

0

20

40

60

80

100

Density (g/cc) % TheoreticalDensity

Elec Conductivity(% IACS)

DiameterShrinkage (%)

ThicknessShrinkage%

Properties

Mea

sure

d Va

lues

UTRON CDC W- 789 (150 tsi) UTRON CDC W-790 (150 tsi) Wrought W Part

Table 10. Results for Sintered CDC Compacted W, Mo and TZM Refractory Disks

Table. 11 CDC Niobium Data Table 11a 1" Niobium Disk 150tsi

Sample #: Description: Density (g/cc) Percent of Theory: Mass: grams OD (in): Thickness (in):

1015 Nb -80/+200 8.2465 96.23 8.024 1.0040 0.0750 1016 Nb <10 microns 8.0214 93.60 7.909 1.0040 0.0760 1018 Nb -80/+200 8.2587 96.37 8.518 1.0040 0.0795 1019 Nb -325 8.1652 95.28 8.519 1.0035 0.0805 1020 Nb <10 microns 8.0045 93.40 8.507 1.0035 0.0820

Table 11c 2" Niobium Disk

Sample #: Description: Green Density (g/cc)

Percent of Theory: Mass: (g) OD

(in): Thickness (in): Load (tsi)

K6 Niobium -80/+200 8.4112 98.15 215.2 2.006 0.494 111.5K7 Niobium -80/+200 8.4112 98.15 215.2 2.006 0.494 99.5K8 Niobium -325 8.3651 97.61 215.1 2.007 0.496 145.3 Theoretical Density: 8.5700

Fig. 16 CDC Niobium Disk (2 inch Dia) SUMMARY CDC high pressure consolidation technology has been used to compact and process a variety of non-ferrous materials including refractory materials to evaluate the materials behavior and properties. This emerging technology has several potential for use in energy, defense and commercial applications as illustrated with select examples in this publication. ACKNOWLEDGMENTS The authors like to acknowledge the funding provided by several SBIR sponsors such as DOE, MDA, NAVY and NASA sponsors. We are also indebted to Mike Kassmier of Brand X-Ray, and Vladimir

Table 11b 1" Niobium Disk Sintered

Sample #: Description: Sintered Density (g/cc)

Percent of Theory: Mass (g) thickness (in) OD (in) %change from

green thickness % change from

green OD

%change die

OD (1.0)

1015 Nb -80/+200 8.0116 93.48 8.0416 0.0760 1.0130 1.33 0.90 1.301016 Nb <10 microns 8.2360 96.10 7.8313 0.0750 0.9925 -1.32 -1.15 -0.751018 Nb -80/+200 8.3305 97.21 8.4871 0.0790 1.0010 -0.63 -0.30 0.101019 Nb -325 8.3791 97.77 8.4600 0.0790 0.9965 -1.86 -0.70 -0.351020 Nb <10 microns 8.3517 97.45 8.4281 0.0800 0.9900 -2.44 -1.35 -1.00

1045 Nb -80/+200 -0.67 -0.17 -0.29 0.03 0.29

Vudler of Hardric Labs and Mike of SPICA, Inc for their assistance with x-ray tube testing and laser optical mirror performance evaluations. REFERENCES [1] I. E. Campisi & L. R. Doolittle from JLAB (Editors), Proceedings of the Workshop on Microwave-

Absorbing Materials for Accelerators, Continuous Electron Beam Accelerator Facility (JLAB-CEBAF), Newport News, VA, Feb 22-24, 1993, pp. 1-385.

[2] I. E. Campisi (JLAB), “Fundamental Power Couplers for Superconducting Cavities,” Research Report/Conf. Paper for the Work Supported by US DOE Contracts Nos. DE-AC05-00OR22725 & DE-AC05-84-ER40150).

[3] C. Adolphsen, J. Cornuelle, T. Lavine, H. Padamsee, and S. Tantawi, (A Summary of the RF-Technology W o rk i n g Group-T3) , October 16, 2001. www.slac.stanford.edu/lc/wkshp/snowmass2001/t3/T3_Group_Report_Long-Version.doc).

[4] S. Tantawi (SLAC, California), New Concepts in Coupler Structures, HPC 2002 Workshop Presentation, JLAB, Newport News, VA, October 30-November 1, 2002.

[5] P. Kneisel, “Development of Seamless Niobium Cavities for Accelerator Applications”, Proceedings of the 1999 Particle Accelerator Conference, NY, pp. 943-945, 1999.

[6] X. Xu, R.S. Callin, W.R. Fowkes, A. Menegat, G.P. Scheiurum, and D. H. Whittum, "RF B r ea kd o w n S t u d i es i n X -B a n d Kly s tron Cav itie s ” (http://accelconf.web.cern.ch/accelconf/pac97/papers/pdf/8PO32.PDF).

[7] S. Kalpakjian, "Competitive Aspects of Manufacturing," in Manufacturing Engineering and Technology, Third Edition, Addison Wesley Publishing Company, 1995, pp. 1216-1243.

[8] C. G. Goetzel, Treatise on Powder Metallurgy, Vol. 2, 1950 [9] W. D. Callister, Materials Sci. & Engg-An Introduction, 1985. [10] J. Mazumder, J. Choi, K. Nagarathnam, J. Koch and D. Hetzner, "Direct Metal Deposition of H13

Tool Steel for 3-D Components," (Laser Based Freeform Fabrication) Journal of Metals, Vol. 49, No. 5, May 1997, pp. 55-60.

[11] K. Nagarathnam and K.M.B. Taminger,(NASA LARC) "Technology Assessment of Laser-Assisted Materials Processing in Space," CP 552, Space Technology and Applications International Forum-2001, paper edited by M.S. El-Genk, pp. 153-160.

[12] G. S. Upadhyaya, " Sintered Metallic and Ceramic Materials-Preparation, Properties and Applications," John Wiley & Sons Ltd, pp. 1-670, 2000.

[13] D. Kruczynski, F.D. Witherspoon and K. Nagarathnam, “Combustion Driven Compaction (CDC) Processing of Aluminum and Metal/Ceramic Alloys for JLAB’s Accelerator Applications,” High Power Coupler (HPC 2002) Workshop Industry Participation/Presentation (Dr. Campisi- Co-Organizer) and UTRON/JLAB Project Reports on CD-Power Point Version Submitted to JLAB (Nov 27, 2002) and Fermi Lab (Dec 2002), pp. 1-50.

[14] ASM Metals Handbook: "Properties and Selection: Nonferrous Alloys and Special-Purpose Materials", Vol. 2, Tenth Edition, ASM. 1-687.

[15] R. W. Balliett et al., “Niobium and Tantalum in Materials Selection,” J. of Metals, Vol. 38, No. 9, p. 25-27, Sep 1986.

[16] "Nanostructure Science and Technology-A Worldwide Study-Panel Report," National Science and Technology Council (NSTC) and The Inter-agency Working Group on Nanoscience, Engg and Technology, Sep 1999.

[17] R. Z. Valiev, T. C. Lowe, and A. K. Mukherjee: Understanding the Unique Properties of SPD-Induced Microstructures," Journal of Metals, Vol. 52, No. 4, 37-40.

[18] B. Kear and G. Skandan, "Nanostructured Bulk Materials: Synthesis, Processing, Properties, and Performance", Chapter 5.

[19] K. Nagarathnam, "Processing and Characterization of Laser-Synthesized Overcoats for Surface Engineering," Ph.D. Thesis, Dept. of Mechanical & Industrial Engineering., Univ.of Illinois, Oct. 1994. [20] D. T. Palmer, M. Hill, S. Schwartzkopf, R. H. Siemann and R. Witherspoon, “Materials Research

Related to W-Band Cavity Construction,” Proc. of 1999 Particle Accelerator Conference, NY, pp. 545-547, 1999.

[21] Conference.kek.jp/SRF2001/pdf/PT024.pdf [22] http//accelconf.web.cern.ch/AccelConf/e02/PAPERS/THPDO029.pdf [23] http//www-project.slac.stanford.edu/nlc/components/copper.html [24] C a vitie s a nd Aux ilia ry Syste m s, Cha p te r 4, TESLA Prog ra m

(http://tesla.desy/de/new_pages/TTFcdrTab.html) [25] T. Tajima,”Possibility of MgB2 Application to Superconducting Cavities,” Proceedings of EPAC

2002, Paris, France. [26] http://www.mpif.org/industry/spch02pub.pdf “State-of -the-Art North American P/M Industry2002. [27] B. Ullrich, June Issue of the International Powder Metallurgy, Vol. 3, No. 4, 2003, pp. 40-46. [28] FermiLab NLC Copper RF Structures/Drawing (#5525-MD-404258) approved on 2/17/03. [29] W. F. Smith, Principles of Materials Science and Engineering, McGraw Hill Publication, pp. 544-545, 1996. [30] D. Witherspoon, K. Nagarathnam, and D. Kruczynski, UTRON’s SBIR Phase I Report, DOE/ER/83567-1, Work Done Under Contract No: FG02-02ER83567, pp. 1-122, July 2003. [31] Karthik Nagarathnam (PI), D. Kruczynski and D. Massey, “ Near Net Shape Manufacturing Using Combustion Driven Compaction,” UTRON’s DOE SBIR Phase I Project Results, Under Contract Number DE-FG02-03ER83816, (7/21/2003- 4/20/2004). [32] http://www.copper.org/resources/properties/microstructure/coppers.html [33] K. Nagarathnam, D. Kruczynski and D. Massey, UTRON’s SBIR Phase II Report, DOE/ER83567-2, Technical Progress Report #1, February 20, 2004. [34] Karthik Nagarathnam et al., UTRON’s DOE SBIR Project Results (2003-Present), UTRON Inc. [35] Karthik Nagarathnam, Donald Trostle, Dave Kruczynski, and Dennis Massey, “Materials Behavior and Manufacturing Aspects of High Pressure Combustion Driven Compaction P/M Components” 2004 Intl Conf. Paper on Powder Metal & Particulate Matls(PM2TEC-2004), Chicago, IL, 2004. Part 9, pp.1-15. [36] Karthik Nagarathnam, "CERAMIC DEFENSE: Pressing with Controlled Combustion"Published in

Ceramic Industry, by BNP media, June 1, 2006, http://www.ceramicindustry.com/CDA/Articles/Feature_Article/10cd85375737b010

[37] Karthik Nagarathnam, Aaron Renner, Donald Trostle, David Kruczynski and Dennis Massey, “DEVELOPMENT OF 1000-TON COMBUSTION DRIVEN COMPACTION PRESS FOR MATERIALS DEVELOPMENT AND PROCESSING,” 2007 MPIF/APMI International Conference Paper on Powder Metallurgy & Particulate Materials, PowderMet 2007, held in Denver, Colorado, May 13-16, 2007 4134.00 [38] http://matweb.com [39] Karthik Nagarathnam, Dave Kruczynski and Dennis Massey, Processing and Properties of CDC Processed Copper and Tungsten , UTRON DOE SBIR PROJECT, Technical Seminar Presentation, FermiLab, Batavia, IL, June 17, 2004 [40] Karthik Nagarathnam, Select Results of UTRON’s NLC Copper Disks, Refractory Materials, Silicon Carbide, Niobium and Press Upgrade by Combustion Driven Compaction DOE SBIR Projects - Status Update, Presentation/Meeting at FermiLab, Batavia, IL, November 18, 2004 [41] Karthik Nagarathnam , Donald Trostle, Jason Zielsdorf and Dennis Massey, Microwave Component Fabrication using the Fast Combustion Driven Compaction, “ DOE-SBIR Phase II FINAL REPORT, Contract #DE FG02-02ER83567, June 22, 2007, pp. 1-151. [42] Karthik Nagarathnam (PI), SBIR Project Reports, UTRON Inc (2003-Present)

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