形变Cu-Cr原位复合材料中纤维相的热稳定性

Thermal stability of Cr filaments in Cu-Cr in-situ composites

研究不同温度时大变形Cu-15Cr-0.1Zr原位复合材料中Cr纤维的热稳定性,采用扫描电镜和透射电镜观察Cr纤维形态变化,测定Cr纤维的断开直径,并进行数值模拟。并根据模界面分裂模型计算了550～900℃时Cr在Cu/Cr界面的界面扩散系数。结果表明:高温条件下纤维的形态由片状到球体化断裂,其过程为,Cr纤维逐步形成空洞、纵向开裂、断开和球化;高温条件下纤维断裂受界面扩散控制。

The thermal stability of Cr filaments in heavily drawn Cu-15Cr-0.1Zr in-situ composite wires was investigated at different temperatures. The shape changes of Cr filaments during annealing were observed by SEM and TEM, the break-up diameters of Cr filaments were determined and simulated. The interface diffusion coefficient of Cr on the Cu/Cr interface at 550-900 ~C was calculated in terms of the boundary splitting models. The results of SEM and TEM show that the transition of Cr filaments from a platelike to a spherical microstructure of Cr filaments at elevated-temperature is as follows： cavitation, longitudinal splitting plus, cylinderization plus, breakup to complete spheroidization failure. The simulating result shows that the fracture behavior of the Cr filaments are controlled by a type of interfacial diffusion at elevated-temperature.