摘要
采用真空热压烧结的方法制备了复合材料Cu-Al_2O_3,并在GLeeble-1500D热模拟机上对其进行高温压缩试验,研究了在变形温度为650~950℃,变形速率为0.01~5s^(-1),最大真应变为0.7条件下的流变应力行为.结果表明:纳米级的弥散粒子和间距能在变形时作为位错源增加基体的位错密度,对位错和晶界运动起到阻碍作用,从而提高其综合力学性能.在试验变形条件下,复合材料Cu-Al_2O_3均表现出典型的动态再结晶特征,即随着峰值应力逐渐减小,在晶界交叉处出现再结晶晶粒,并逐渐增多,复合材料高温变形的主要软化机制为动态再结晶.
Cu-Al2O3 composites were fabricated by vacuum hot-pressing sintering technique. Flow stress behavior and softening mechanism of the composites were investigated through high temperature compression tests. The tests were carried out using Gleeble-1500D thermal simulation apparatus. The deformation temperature was 650-950 °C ？the deformation rate was 0. 01-5s^-1 and the maximum true strain was 0. 7. The results indicated that the nanoscale dispersed particles could increase the dislocation density of the matrix during the deformation, which could hinder the movement of dislocations and grain boundaries, and improve the mechanical properties of the composites. Typical dynamic recrystallization characteristics were also observed in the test. As the peak stress gradually decreased,recrystallized grains appeared at the grain boundary and gradually increased. It indicated that the main softening mechanism of the composites during hot high
出处
《有色金属材料与工程》
CAS
2017年第4期210-214,共5页
Nonferrous Metal Materials and Engineering
