Fabrication of Amorphous Alloy Surface Composites by High-energy Electron-beam Irradiation

摘要

In this study, Zr-based amorphous alloy surface composites were fabricated by high-energy electron beam irradiation, and their microstructure, hardness, wear resistance, and thermal conductivity were investigated. Two kinds of Zr-based amorphous powders were mixed with LiF+MgF_2 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 dendrites 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. The thermal conductivity of the amorphous alloy surface composites was much lower than that of stainless-steel-based surface composites. These findings suggested the possibility of applying Zr-based amorphous alloy surface composites to wear-resistant thermal barrier coatings or parts.