Interfacial Oxides Evolution of High-Speed Steel Joints by Hot-Compression Bonding

The interfacial oxidation behavior of Cr4Mo4V high-speed steel (HSS) joints undergoing hot-compression bonding was investigated by using optical microscopy (OM), scanning electron (SEM), and transmission (TEM). In the heating holding processes, dispersed rod-like granular $$\delta - {\text{Al}}_{{2}} {\text{O}}_{{3}}$$ oxides were formed at interface in matrix near due to selective internal Al, while irregular Si–Al–O compounds spheroidal SiO2 particles interface. After post-holding treatment, dissolved into matrix, transformed nanoscale $$\alpha particles, which did not deteriorate mechanical properties joints. formation migration newly-formed grain boundaries plastic deformation treatment main mechanism for healing. tensile test results showed that strength healed comparable base material, in-situ observations proved fracture initiated boundary rather than clarification microstructure is essential application HSSs.