Microstructure and wear resistance of TaC reinforced Ni-based coating by laser cladding

✍ Scribed by Ming-ju Chao; Wen-li Wang; Er-jun Liang; Dongxun Ouyang

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 829 KB
• Volume: 202
• Category: Article
• ISSN: 0257-8972
• DOI: 10.1016/j.surfcoat.2007.08.021

✦ Synopsis

The in situ synthesized TaC particulate reinforced Ni-based composite coating was fabricated on a mild steel by laser cladding of powder mixture of Ni60 alloy powder with (Ta 2 O 5 + C)-doping. The microstructure and wear resistance of the TaC/Ni60 composite coating were investigated. It is shown that the coating is bonded metallurgically to the substrate and has a homogeneous fine microstructure containing both approximate cubic TaC particle and acicular chromium carbide uniformly dispersed in the dual phase matrix of γ(Ni) solid solution and eutectic of Cr 3 C 2 , Fe 2 B with γ(Ni). Compared to a Ni60 coating, the hardness of the TaC/Ni60 composite coating was enhanced by a factor of 1.38, could achieve a Vicker microhardness of Hv 0.3 1100. And the wear rate in a block on ring test against hardened steel was reduced by a factor of five. This is attributed to the presence of in situ synthesized TaC particles and their well distribution in the coating.