大塑性变形状态下黄铜的孪生变形研究

摘要

It is proved that the sever plastic deformation is an effective approach to producation of ultrafine grain and nanocrystal ine metal ic materials. Two different deformation methods, namely equal channel angular pressing and rol ing, are used to deform the brass H85 and H90. Through the microstructure observation, effect of pressure on brass plastic deformation mechanism is studied. Results show that twin density increases with increase in pressure, and plasticity and strength can be improved. In addition, lower stacking fault energy can promote twin nucleation earlier and the strengthening ability is improved greatly.%大塑性变形是获取纳米孪晶材料的重要方法，为研究压力对铜锌合金变形行为的影响，分别采用等径角挤压和冷轧的方法使H85和H90黄铜试样进行发生塑性变形。通过微观组织观测，发现较大的压力下，两种材料的塑性变形机制是以孪生机制为主导的，较低的层错能可以使孪生优先形核，提高强化能力。