The Effect of Heat Treatment on Microstructure and Performance of Die Forging Copper

Abstract

The copper specimen was fabricated through liquid die forging under optimum technical parameter, and the die forging copper was annealed under different conditions. The effect of annealing treatment on the microstructure, strength, hardness and electric conductivity of die forging copper was investigated. The results show that the microstructure of die forging copper was changed into equiaxed grain when the treating temperature was less than 250 °C and treating time was less than 2.0 h. The restoration and recrystallization happened during treatment and the obtained crystal grain size became smaller. The strength of die forging copper decreased after annealing treatment owing to the decreasing of dislocation density and concentration of supersaturated vacancy. The hardness of die forging copper also dropped to some extent. The electric conductivity of die forging copper was increased by 5.2% after annealing treatment because the concentration of supersaturated vacancy and dislocation density was decreased obviously.