Effects of surface modification on fuel-lubricated tribological behavior of WC-Co thermal spray coating

The objective of this study is to evaluate the effects of ultrasonic nanocrystal surface modification (UNSM) on the tribological behavior of WC-Co thermal spray coatings for fuel-lubricated components. UNSM reduced the average surface roughness from 4.22 mu m down to 2.26 mu m and increased the hardness from 861 HV1 up to 1091 HV1. UNSM reduced the intensity and broadened the full width at half maximum of X-ray diffraction peaks, which indicated a combination of refinement in grain size and introduction of compressive residual stress. The coefficient of friction under fuel lubrication was reduced significantly by UNSM from 0.083 to 0.011, while the specific wear rate decreased from 6.21 +/- 1.41 x 10(-13) mm(3)/N x m to 2.07 +/- 0.36 x 10(-13) mm(3)/N x m after UNSM.

Automated summary

This study evaluates the effects of ultrasonic nanocrystal surface modification (UNSM) on the tribological behavior of WC-Co thermal spray coatings for fuel-lubricated components. The results show that UNSM reduces surface roughness, increases hardness, refines grain size, and introduces compressive residual stress. Under fuel lubrication, UNSM significantly reduces the coefficient of friction and specific wear rate.