Near Full Density As Sintered Powdered Metal (P/M) Parts Produced From Water Atomized Powder With Properties Comparable To Wrought Steel

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Near Full Density As Sintered Powdered Metal
(P/M) Parts Produced From Water Atomized Powder
With Properties Comparable To Wrought Steel
Richard R. Phillips - Engineered Pressed
Materials Dennis Hammond - APEX Advanced
Technologies, LLC
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Key Features of the Technology

• Water atomized powder
• Low alloy steel -100 mesh
• gt99.5 theoretical density
• Properties comparable or superior to
• wrought steel
• Standard tooling/ conventional pressing
• Normal compaction range

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Key Features of the Technology Continued

• High temperature sintering lt 2500F (atmospheric
  or vacuum)
• Conventional steel heat treating
• Post heat treating operations similar to wrought
  processing

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Lubricant Requirements For Near Full Density P/M
Parts

• Increase green density
• Mobility of the lubricant
• Effective removal of the lubricant
• Excellent dimensional stability

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High Green Density with Standard Equipment

• Reduced level of lubricant, typical use level
  .25-.4
• Green Densities 7.2-7.4 g/cc typical for common
  formulas
• Micro cracking and delamination eliminated
• Green density increased due to reduced volume of
  lubricant and better fit of particles resulting
  from mobility of the lubricant
• Lubricant is more effective

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Mobility of Lubricant

• Lubricant transforms with shear, pressure, and
  friction from a solid to a viscous liquid at
  relatively low pressure ( 4 tsi with shear)
• Mobility allows for effective rearrangement of
  metal particles
• Mobility allows for lubricant to be forced to the
  die wall as well as hydrostatic environment
  within the compact

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Effective Removal of the Lubricant

• Environmentally friendly,contains no metal
• Staggered decomposition rate
• Up to 70 less gas trying to exit the part at
  peak decomposition relative to conventional
  lubricants
• Elimination of cracking and blistering with high
  nickel formulas
• Elimination of recondensation of lubricant on
  part surfaces

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Excellent Dimensional Stability

• No micro cracks or delamination
• Small uniform pore size in the green state
• No unplanned density gradients in the part
• Relatively stress free green part
• Density split eliminated
• Uniform, predictable shrinkage
• Enhanced sintering efficiency

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Other Part Attributes

• Good surface finish
• Good ejection with reduced level of lubricant
• Due to the high green densities achieved,
  excellent green strength is also obtained

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Density Gradient Shape Retention
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Density Gradient Shape Retention
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Pressure/Density Curve FLN-0706
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Materials and Processing(Experiments)
Standard MPIF ASTM Comments
Density 42 B328 Modified Method
Hardness Macro 43 E18
Impact Notched E23
Impact Un-notched 40 E23
Modulus of Elasticity 10 E8
Ultimate Tensile Strength 10 E8
Yield Strength 10 E8
Elongation 10 E8
Microstructure E3
Photomicrographs E883
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Test Alloys

• Hoeganaes Ancorsteel? 85HP and 150HP formulated
  to provide a resulting alloy with 0.56Carbon and
  Nickel contents between 2 and 6.6.
• Pressed at 276 (20),414 (30), 552 (40) ,690 (50),
  and 828 (60) MPa (TSI).
• Vacuum or Atmosphere High Temperature Sintering
• Heat Treated to Commercial Wrought Steel
  Properties

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Tensile Data
Sample Type Density, g/cc UTS, MPa (103 psi) 0.2 YS, MPa (103 psi) Elong. ROA Mod of Elas., GPa (106 psi) Hardness HRC
Pressed 7.81 1,486 (215) 1,296 (187) 3.1 188 (27.3) 43.5
Machined 7.79 1,383 (200) 1,304 (189) 2.9 9.34 182 (26.4) 45.0
Pressed 7.59 1,446 (209) 1,205 (175) 4.0 158 (22.9) 39.7
Machined 7.57 1,414 (205) 1,248 (181) 4.2 10.48 162 (23.5) 38.7

Pressed 7.82 1,182 (171) 955 (138) 5.2 183 (26.6) 34.3
Machined 7.79 987 (143) 939 (136) 3.5 11.51 192 (27.8) 35.4
Pressed 7.46 1,051 (152) 685 (99) 4.4 141 (20.4) 28.0
Machined 7.57 1,314 (190) 1,211 (176) 4.9 15.92 164 (23.8) 37.5

Pressed 7.76 1,062 (154) 803 (116) 8.6 170 (24.6) 32.0
Machined 7.79 1,036 (150) 787 (114) 4.2 13.48 171 (24.8) 32.6
Pressed 7.60 1,188 (172) 690 (100) 4.0 136 (19.8) 36.7
Machined 7.57 1,089 (158) 730 (106) 7.4 15.19 135 (19.6) 32.0
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Comparison to Wrought Tensile Data
Grade UTS MPa (103 psi) 0.2 Y.S. MPa (103 psi) Elongation Hardness, HRC Scale
ANP FLN-0706 Range of Data 1,486 (215.4) 1,383 (200.5) 1,296 (187.9) 1,304 (189.1) 3.1/2.9 43.5/45.0
AISI 4140 1,449 (210) 1,346 (195) 14 45
AISI 4340 1,449 (210) 1,325 (192) 14 45
AISI 5140 1,304 (189) 1,228 (178) 14 40
AISI 4150 1,573 (228) 1,484 (215) 9 47
AISI 5150 1,435 (208) 1,346 (195) 11 45
AISI 6150 1,401 (203) 1,325 (192) 10 46
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Comparison to Wrought Tensile Data
Grade UTS MPa (103 psi) 0.2 Y.S. MPa (103 psi) Elongation Hardness, HRC Scale
ANP FLN-0706 Range of Data 1,182 (171.3) 987 (143.1) 955 (138.4) 939 (136.1) 5.2/3.5 34.3/35.4
AISI 4140 1,021 (148) 917 (133) 18 33
AISI 4340 1,049 (152) 979.8 (142) 18 34
AISI 5140 911 (132) 800 (116) 20 28
AISI 4150 1,242 (180) 1,118 (162) 12 39
AISI 5150 980 (142) 911 (132) 18 31
AISI 6150 1,125 (163) 1,063 (154) 15 36
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Comparison to Wrought Tensile Data
Grade UTS MPa (103 psi) 0.2 Y.S. MPa (103 psi) Elongation Hardness, HRC Scale
ANP FLN-0706 Range of Data 1,062 (154.0) 1,036 (150.2) 803 (116.5) 787 (114.2) 8.6/4.2 32.0/32.6
AISI 4140 814 (118) 697 (101) 23 22
AISI 4340 911 (132) 800 (116) 24 20
AISI 5140 787 (114) 580 (84) 27 95 HRB
AISI 4150 876 (127) 807 (117) 20 27
AISI 5150 807 (117) 711 (103) 23 23
AISI 6150 814 (118) 738 (107) 22 23
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Charpy Impact Comparison
Density, g/cc FLN-0706 (No Notch), ft-lbf FLN-0706 (Notched), ft-lbf Wrought (Notched), ft-lbf
7.8 50 7 12 - 17
7.6 55 6
7.8 77 13 36 - 56
7.6 67 11
7.8 84 77 - 87
7.6 70
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Size Change/Coefficient of Variance
Coefficient of Dimensional Variance () Equal to
the standard deviation divided by the average
multiplied by 100 Pressed Direction
0.17 Perpendicular to Pressed Direction 0.084
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Cylinders
Back row in the as-molded condition. Front row in
sintered and heated condition. OD 1.880 , OAL
1.755, 1.500, 0.750, 0.500
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Processed Samples
Samples in molded, sintered and heat treated, and
machined condition. (7.81 g/cc, 45 HRC)
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Gears, Pawls and Rollers
Back row in the as-molded condition. Front row in
sintered and heated condition.
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Density
7.84 g/cc (gt99.5 Theoretical Density)
7.41 g/cc (95 Theoretical Density)
6.70 g/cc (85 Theoretical Density)
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Future Analysis (Fatigue)
Stress Endurance values for various sets of
process conditions
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P/M and Other Process Costs
Machining Precision Casting
Powder Forge
Double Press Double Sinter
High Velocity Compaction (Double Press Double
Sinter)
Relative Cost
Single Press Sinter
Warm Compaction
High Velocity Compaction
ActivatedTM NanotechTM Sinter
Density (g/cm3)
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Conclusions

• ANPTM processing of -100 mesh ferrous powder
  alloys creates material properties similar to
  wrought product.
• ANPTM utilizes conventional blending, tooling and
  P/M molding capabilities.
• Lubricant choice plays a critical role.
• ANPTM is activated during high temperature
  sintering resulting in densification gt 99.5 of
  theoretical (pore-free).
• ANPTM dimensional control is predictable and
  uniform within lt 0.2 variance.

ANPTM, ACTIVATEDTM NANOTECHTM are trademarks of
Material Technologies, Inc. Patent Pending
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Conclusions (cont.)

• ANPTM can utilize conventional wrought metal
  processing to meet specific engineering design
  requirements to enhance optimum product
  performance.
• Machining without lubricant intrusion.
• Plating without impregnation.
• Salt Bath Processing
• Kolene Nu-tride
• Blueing
• Ferritic Nitrocarburizing (Atmosphere).

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Conclusions (cont.)

• ANPTM parts can be pressed from 276 (20) to 828
  (60) MPa (TSI) and still sinter to full density.
• Further development work will result in even
  greater performance.
• Work continuing on a broader selection of alloys.