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Sliding Wear of Tungsten-Carbide Thermal Spray Coatings Standard Grind and Superfinished HCAT Meeting August 28 – 30, 2001 Toronto, Ontario, Canada SOUTHWEST Aeroservice, Inc.
Sliding Wear of Tungsten-Carbide Thermal Spray Coatings
Standard Grind and Superfinished
HCAT Meeting
August 28 – 30, 2001
Toronto, Ontario, Canada
SOUTHWEST Aeroservice, Inc.
Outline
• Objectives
• Experimental Procedure
• Wear Test Schematic and Machine
• Specimens
• Results
SOUTHWEST Aeroservice, Inc.
Objectives
• Compare sliding wear characteristics of standard grind thermal spray coatings to superfinished coatings.
• Compare sliding wear characteristics of thermal spray coatings to chrome plating – standard grind and superfinished.
SOUTHWEST Aeroservice, Inc.
Experimental Procedure
• Perform sliding wear test according to ASTM G77 standard
• Quantify wear for each coating type and chrome plating (standard grind and superfinished) against Al-Ni-Bz bearing material
• Standard grind finish defined as 16 –32 Ra• Superfinish defined as 4 Ra or less
SOUTHWEST Aeroservice, Inc.
ASTM G77 Wear Test Schematic
The thermal spray coated test ring rotates against a stationary Al-Ni-Bz test block with a 15 1b contact force. Boeing grease BMS 3-33 was used as lubricant between block and ring.
SOUTHWEST Aeroservice, Inc.
Wear Test Machine
Load Cell
RingBlock
SOUTHWEST Aeroservice, Inc.
Wear Test Procedure
• Weigh ring and block before test
• Install ring, block, and grease feeder
• Run test for 30 min with load applied –
6.8 kg (15-lb)
• Clean off grease from ring and block
• Weigh ring and block after test
• Measure volume loss from blocks
SOUTHWEST Aeroservice, Inc.
Wear Test Procedure
• Quantify volume loss from block by measuring width of scar
SOUTHWEST Aeroservice, Inc.
Wear Test Specimens
SW Coating # Coating Type Spray gun
SWATS 12583WC-17Co
High Comp StressJet Kote
SWATS 07683WC-17Co Tensile Stress
Jet Kote
SWATS 139 86WC-10Co-4Cr Jet Kote
SWATS 141 83WC-17Co Diamond Jet
SWATS 140 86WC-10Co-4Cr Diamond Jet
SOUTHWEST Aeroservice, Inc.
Wear Test Specimens
• Rings (1.377 in dia. coated on O.D.)– Coatings
• SWATS 125
• SWATS 076
• SWATS 139
• SWATS 141
• SWATS 140
SOUTHWEST Aeroservice, Inc.
Wear Test Specimens
• Blocks (0.625 x 0.40 x 0.25 in)– Al-Ni-Bz (Common aircraft bearing material)– Also Coatings
• SWATS 125
• SWATS 076
• SWATS 139
• SWATS 141
• SWATS 140
SOUTHWEST Aeroservice, Inc.
Wear Test ResultsVolume Loss of Al-Ni-Bz Blocks
0.0E+00
4.0E-06
8.0E-06
1.2E-05
1.6E-05
2.0E-05
2.4E-05
SWATS125
SWATS076
SWATS139
SWATS141
SWATS140
Chrome
Coating Type
Vo
lum
e L
oss
, in
^3
Std Finish
SuperfinishMeasurementAccuracy +/- 2.0e-7 in 3̂
Error bars indicate range of data
125 = WC-Co JK(Compressive)
076 = WC-Co JK(Tensile)
139 = Co-Cr JK(Compressive)
141 = WC-Co DJ(Compressive)
140 = Co-Cr DJ(Compressive)
SOUTHWEST Aeroservice, Inc.
Wear Test ResultsVolume Loss of Self-Test Blocks
0.E+00
1.E-07
2.E-07
3.E-07
4.E-07
5.E-07
6.E-07
7.E-07
SWATS 125 SWATS 076 SWATS 139 Chrome
Coating Type
Vol
. Los
s, in
^3
Std. Finish
SuperfinishMeasurementAccuracy +/- 1.5e-8 in^3
Error bars indicate range of data
125 = WC-Co JK(Compressive)
076 = WC-Co JK(Tensile)
139 = Co-Cr JK(Compressive)
SOUTHWEST Aeroservice, Inc.
Wear Test ResultsRing Weight Change against Al-Ni-Bz Blocks
-0.002
-0.001
0
0.001
0.002
0.003
0.004
0.005
SWATS 125 SWATS 076 SWATS 139 SWATS 141 SWATS 140 Chrome
Coating Type
Wei
ght D
iffer
ence
, g
Std. Finish
SupefinishMeasurementAccuracy +/- 0.5 mg
125 = WC-Co JK(Compressive)
076 = WC-Co JK(Tensile)
139 = Co-Cr JK(Compressive)
141 = WC-Co DJ(Compressive)
140 = Co-Cr DJ(Compressive)
SOUTHWEST Aeroservice, Inc.
Wear Test ResultsRing Weight Change against Self-Test Blocks
-0.002
-0.001
0
0.001
0.002
0.003
0.004
0.005
SWATS 125 SWATS 076 SWATS 139 Chrome
Coating Type
Wei
ght D
iffer
ence
, g
Std. Finish
SuperfinishMeasurement
Accuracy +/- 0.5 mg
125 = WC-Co JK(Compressive)
076 = WC-Co JK(Tensile)
139 = Co-Cr JK(Compressive)
SOUTHWEST Aeroservice, Inc.
This is a preliminary report of findings. T.U. will be presenting the complete results at the ASM International Materials Solutions Conference in Indianapolis on Wednesday November 7, 2001.
SOUTHWEST Aeroservice, Inc.
