SYNTHESIS AND CHARACTERIZATION OF Zr-BASED AMORPHOUS AND CRYSTALLINE COMPOSITE COATING ON Ti SUBSTRATE BY LASER CLADDING

摘要

A thin strip of a Zr-based alloy with a composition of Zr_(60)Cu_(25)Fe_5Al_(10) (in atom percent) was used as a raw material, and the composite coatings containing Zr-based amorphous phase and crystallites on Ti substrate were fabricated by a one-step laser cladding method without protection. The micro- structure, phase constitution, microhardness and wear properties of the coatings were investigated. The results indicate that the microstructure of the coatings is strongly dependent on the laser scanning speed under the conditions of the laser power of 1300 W and laser beam diameter of 6 mm, and the composite coating mainly containing amorphous phase with a small amount of the crystallites can be obtained at the laser scanning speed of 10 mm/s. The composite coating exhibits much higher microhardness than the pure Ti substrate, and thus it behaves superior wear resistance in comparison with the substrate.