Improving wear resistance and friction stability of FeNi matrix coating by in-situ multi-carbide WC-TiC via PTA metallurgical reaction

摘要

This paper presents a new type of FeNi matrix composite coating reinforced with multi-scale carbides WC-TiC fabricated by in-situ synthesis method PTAMR (plasma transferred arc metallurgical reaction). The microstructures, phases, hardness, and tribology properties of the composite coating were analyzed. Results show that the multi-scale carbides WC-TiC with fine intact shape were successfully in-situ synthesized in the matrix. Owing to the in-situ synthesis method, plenty of TiC tiny carbides in-situ grow in both the carbide WC and matrix, known as the precipitation hardening, by which the hardness of carbide WC and matrix are increased from 1497 to 1682 HV4.9 and 411 to 731 HV4.9 respectively. The analysis of crystallographic relationship shows that the lattice misfit between (10 (1) over bar0)(WC) and (001)(TiC) is 6.26%, indicating carbides WC and TiC can act as mutual effective heterogeneous nuclei and promote each other. Benefit from the in-situ WC-TiC multi-scale carbides hybrid growth characteristic, the wear resistance, and frictional stability are all increased in compared with the coating reinforced with in-situ single-carbide WC.