In-situ-growth of hard-coating,its impact on mechanical performances in cemented-carbides

Abstract

This study focuses on preparing two types of cemented carbides: one with Ti elements and the other without, using a stepwise sintering process, primarily evaluating their mechanical properties. The research includes a thorough analysis of microstructure changes and post-wear surface alterations, coupled with assessments of phase composition, element content, relative density, surface hardness, fracture toughness, and wear properties. Results reveal that cemented carbides treated with in-situ surface modification under high-temperature nitrogen atmospheres exhibit exceptional densification. An in-situ hard-phases layer, predominantly TiN or Ti(C, N), is gradually grown on the surface of the WC-Co-Mo-TiNC cemented carbides, enhancing surface hardness and fracture toughness. This technology fortifies the material against indentation, crack expansion, and fracture, significantly improving wear resistance and extending service life. In essence, the in-situ surface modification technology, especially under high-temperature nitrogen atmospheres, emerges as a transformative approach, enhancing mechanical properties and substantially improving wear resistance for prolonged practical applications.