화학공학소재연구정보센터
Materials Chemistry and Physics, Vol.206, 1-6, 2018
Sliding wear behavior of HVOF sprayed WC-(nano-WC-Co) coating at elevated temperatures
WC-(nano-WC-Co) coating with a low decomposition degree was prepared by high-velocity oxygen-fuel (HVOF) process. The structure, mechanical properties and wear performance at elevated temperatures were investigated. The results show that the WC-(nano-WC-Co) coating exhibits a dense structure (porosity <1.0%) and a bimodal WC particle size distribution (0.5-1.0 mu m and 30-100 nm). The hardness and fracture toughness of the WC-(nano-WC-Co) coating are 1164 +/- 117 HV0.1 and 11.5 +/- 1.4 MPa m(1/2), respectively. After friction, the surface hardness first increases and then decreases, the highest hardness of 1316 +/- 102 HV0.1 is maintained as the test temperature is 450 degrees C. With the increase of the test temperature, the friction coefficient decreases gradually and the wear rate first decreases and then increases. The minimum value of wear rate of 2.96 x 10(-6) mm(3)N(-1).m(-1) is obtained at 450 degrees C. The continuous oxide films, composed of WO3/WO3-CoWO4 on the worn surface, could reduce friction coefficient and wear rate. (C) 2017 Elsevier B.V. All rights reserved.