采用金相显微镜、维氏硬度仪和万能实验机对H65黄铜合金连续挤压过程中的组织和性能演变特征进行研究。结果表明:连续挤压过程中合金发生了强烈的剪切变形,产生大量的位错和位错缠结,形成取向差较小的亚晶结构;随着变形程度的加剧,合金的温度升高,促进了动态再结晶的发生,小角度晶界通过吸收位错等方式长大成大角度晶界,使亚晶逐渐转变成细小均匀的等轴晶,有效地提高了材料的综合性能。这种组织的演变在力学实验中得到证明。
The microstructure and properties evolution of H65 brass alloy during continuous extrusion were observed by OM, hardness-testing devices and universal-testing machine. The results show that severe plastic deformation (SPD) occurs in continuous extrusion of H65 brass alloy. A large number of dislocation and dislocation twins form. The sub-crystallization structure can be achieved. With increasing friction and temperature, the dynamic recrystallization occurs. After that, the low angle boundaries grow up to high angle boundaries through absorbing dislocation power. The homogeneous grain can be achieved. Continuous extrusion improves the properties of the material effectively. The microstructure evolution is demonstrated in the mechanical property experiments.