Hardness and wear resistance of Zr-based bulk metallic glass/Ti surface composites fabricated by high-energy electron beam irradiation

In this study, Zr-based bulk metallic glass (BMG)/Ti surface composites were fabricated by high-energy electron beam irradiation, and their microstructure, hardness, and wear resistance were investigated. Two kinds of Zr-based amorphous powders were mixed with LiF + MgF2 flux powders, and were deposited on a pure titanium substrate, on which electron beam was irradiated to fabricate one-layered surface composites. Two-layered surface composites were also fabricated by irradiating electron beam again onto the powder mixture deposited on the one-layered surface composites. The composite layers of 1.2–1.4 mm in thickness were homogeneously formed without defects, while they contained some fine crystalline particles or relatively coarse dendrite phases in the amorphous matrix. The hardness and wear resistance of the two-layered surface composites improved over the one-layered surface composites or stainless-steel-based surface composites fabricated with ceramic powders because of the very hard amorphous matrix of the surface composite layer. These findings suggest potentials of the BMG surface composites for applications requiring good wear resistance because they have excellent bonding strength as well as very high hardness and wear resistance.