(上海理工大学 材料科学与工程学院，上海 200093)
摘 要: 采用冷轧变形结合中间退火得到形变Cu-15Cr原位纤维增强复合材料。利用扫描电镜、电子拉力试验机及数字微欧计研究退火温度对材料的Cr纤维形貌、抗拉强度及导电性能的影响。结果表明：Cr纤维的高温不稳定性是边缘球化和晶界开裂的结果；随退火温度升高，Cr纤维的高温失稳过程为Cr纤维发生边缘球化、球化向Cr纤维中心扩展、Cr纤维晶界开裂(三叉晶界处)、Cr纤维断裂。随退火温度升高，Cu-15Cr原位复合材料抗拉强度逐渐降低，导电率先逐渐升高，在550 ℃达到峰值84.4%IACS后迅速下降；经450 ℃退火，能得到具有较好综合性能的冷轧Cu-15Cr原位复合材料，其抗拉强度达到656 MPa，导电率达到82%IACS。
关键字: Cr纤维相；高温稳定性；边缘球化；晶界开裂；抗拉强度；导电率
high temperature stability of Cr filamentary
（School of Materials Science and Engineering, University of Shanghai for Science and Technology,
Shanghai 200093, China）
Abstract:Cu-15Cr in-situ filament-reinforced composites sheets were prepared by cold-rolling and annealing heat treatment. The effects of annealing temperature on Cr filamentary morphology, mechanical and electrical properties of Cu-15Cr in-situ composites were investigated by scanning electronic microscopy (SEM), tensile test and conductivity measurement using micro- ohmmeter. The results show that the reason of high-temperature instability of Cr filament is edge spheroidizing and grain boundary cracking, the failure process of Cr filaments at elevated-temperature is as follows: edge spheroidizing, edge spheroidizing extends to center of Cr filament, grain boundary cracking (trigeminal-phase), fibrous fracture. The tensile strength of Cu-15Cr in-situ composite reduces gradually with increasing annealing temperature, but the electrical conductivity increases gradually first and reaches a maximum 84.4%IACS and then decreases rapidly. After annealing treatment at 450 ℃, the Cu-15Cr in-situ composites show an excellent combination of the tensile strength of 656 MPa and electrical conductivity of 82%IACS.
Key words: Cr filamentary; high temperature stability; grain boundary cracking; edge spheroidizing; tensile strength; electrical conductivity
