The relationship among microstructure evolution, mechanical property and in situ reaction mechanisms in preparing Cu–1.6wt%TiB2 alloys

The Cu–1.6wt%TiB2 alloys have been prepared by combining mechanical alloying and heat treatment. The relationship among microstructure evolution, mechanical property and in situ reaction mechanisms in synthesizing Cu–1.6wt%TiB2 alloys was investigated. It is shown that the temperature 750 °C measured by DSC can cause the occurrence of in situ reaction between B and Ti elements in the Cu–B–Ti alloy powders ball milled for 40 or 60 h; An upward trend of the hardness appears after heat treatment at 700 °C, and the highest value reaching 335HV, but a downward trend appears after heat treatment at either 500 °C or 900 °C; Many coarse B particles were formed in the copper matrix after heat treatment at 500 °C, the number and size of the formed B particles significantly increases with increasing time, but many reaction boundaries (or TiB2 films) and finer TiB2 particles can be formed after heat treatment at both 700 °C and 900 °C. The different in situ reaction models between Cu–B and Cu–Ti alloy micelles with different distribution levels were established and analyzed.