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 Ring Block 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 TypeSpray gun SWATS WC-17Co High Comp Stress Jet Kote SWATS WC-17Co Tensile Stress Jet Kote SWATS 13986WC-10Co-4CrJet Kote SWATS 14183WC-17CoDiamond Jet SWATS 14086WC-10Co-4CrDiamond 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 Results SOUTHWEST Aeroservice, Inc.

Wear Test Results SOUTHWEST Aeroservice, Inc.

Wear Test Results SOUTHWEST Aeroservice, Inc.

Wear Test Results 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, SOUTHWEST Aeroservice, Inc.