SiC_P/Al-Cu复合材料的高温热变形行为

Hot Deformation Behavior of SiC_P/Al-Cu Composite

利用Gleeble-1500D热模拟试验机对SiC_p/Al-Cu复合材料进行压缩实验,研究其在温度为350~500℃、应变速率为0.01~10s-1条件下的高温塑性变形行为。由实验得出变形过程中的应力-应变曲线,建立了热变形本构方程和加工图。结果表明:复合材料高温流动应力-应变曲线主要以动态再结晶为特征,峰值应力随变形温度的降低或应变速率的升高而增加。其热压缩变形时的流变应力可采用Zener-Hollomon参数的双曲正弦形式来描述,在实验条件下平均热变形激活能Q为320.79kJ/mol。确定了加工图中的稳定区和失稳区,分析了加工图中不同区域的显微组织结构,失稳区存在颗粒破裂、孔洞等。

Using the Gleeble-1500 Dsimulator,the high temperature plastic deformation behavior of SiC_p/Al-Cu composite were investigated at 350-500℃ with the strain rate of 0.01-10s^（-1）.The true stress-strain curves were obtained in the tests.Constitutive equation and processing map were established.The results show that the softening mechanism of dynamic recrystallization is a feature of high-temperature flow stress-strain curves of SiC_p/A1-Cu composite,and the peak stress increases with the decrease of deformation temperature or the increase of strain rate.The flow stress behavior of the composite during hot compression deformation can be represented by a Zener-Hollomon parameter in the hyperbolic sine form.Its activation energy for hot deformation Qis 320.79kJ/mol.The stable regions and the instability regions in the processing map were identified and the microstructures in different regions of processing map were studied.There are particle breakage and void in the instability regions.