Effect of Y precursors on the synthesis of Cu-Y2O3 by mechanical alloying and spark plasma sintering

This work prepared the Cu-Y2O3 alloy through mechanical alloying and spark plasma sintering. Based on the insitu reaction principle, Y salts were used as a precursor of Y2O3 dispersoid instead of pure Y powder, and the influence of different Y salts on the microstructure, mechanical, and physical properties of the copper matrix was researched. The results indicate that Y salts can effectively prevent the cold welding effect of pure Y metal powder, thereby improving the homogeneity and refinement effect of alloying. Among different Y salts samples, Y(NO3)3 & sdot;6H2O and Y2(SO4)3 & sdot;8H2O may cause varying degrees of contamination to the copper matrix, affecting the material properties. In comparison, Y2(CO3)3 has the advantage of low decomposition temperature and the decomposition product CO2 does not react with the copper matrix. It successfully refined the average particle size of Y2O3 from 8.8 f 3.7 nm to 5.5 f 2.8 nm, increased the number density from 2.37 x 1021/m3 to 7.46 x 1021/ m3, and obtained a tensile strength of 291 MPa and an elongation of 19.8 % at room temperature, with a thermal conductivity of 322 W/(m K) at 400 degrees C for the Cu-Y2O3 alloy. This validates the feasibility of combining Y salts with mechanical alloying. The preparation of high-strength, high-conductivity Cu alloys holds significant reference value.