Microstructure, tribological property and high temperature tensile property of Co-Cr-Ni-W alloy parts fabricated by laser directed energy deposition

• Published in: Surface & coatings technology 2024-05, Vol.483, p.130807, Article 130807
• Main Authors: Huang, Y.C., Wu, H., Xu, T.Z., Wang, R., Zhang, S., Zhang, C.H., Wu, C.L., Chen, H.T.
• Format: Article
• Language: English
• Subjects: Co-Cr-Ni-W alloy; High temperature tensile property; Laser directed energy deposition; Microstructural transformation; Tribological property
• ISSN: 0257-8972
• DOI: 10.1016/j.surfcoat.2024.130807

In this study, Co-Cr-Ni-W alloy parts were fabricated on the surface of 304 stainless steel (SS) substrate by laser directed energy deposition (LDED). Microstructure, microhardness and tribological behavior of as-deposited samples and 750 °C–950 °C aging-treated samples were tested. Carbides precipitated from Co-Cr-Ni-W alloy, and martensite transformation from γ-Co (FCC) to ε-Co (HCP) occurred in high temperature. The changes of microstructure caused by aging treatment could increase the microhardness and change wear mechanism. Tensile property of Co-Cr-Ni-W alloy at 750 °C–950 °C was also investigated. Co-Cr-Ni-W alloy formed a hard-sliding structure under high temperature, leading to high tensile strength. The main fracture mode of Co-Cr-Ni-W alloy was brittle cleavage fracture. •Discussed the effects of various elements in laser clad Co-Cr-Ni-W alloy•Revealed the wear mechanism of laser clad Co-Cr-Ni-W alloy•Evaluated the tensile property of Co-Cr-Ni-W alloy at high temperatures•Analyzed the fracture mechanism of Co-Cr-Ni-W alloy during stretching