形变Cu-10%Cr-3%Ag原位复合材料研究

Study of Deformation-Processed Cu-10%Cr-3%Ag in Situ Composites

对形变Cu-10%Cr-3%Ag原位复合材料形貌、强度和导电性进行了研究.用扫描电镜观察发现,Cr相在形变过程中由铸态的树枝晶变形成为纤维,横截面呈弯曲状薄片,形变量越大,纤维越均匀细密.力学性能和电阻率测试结果发现,随形变量增加,强度提高,电阻率增大.中间热处理对强度和导电性均有影响,在形变量一致的情况下,中间热处理温度太高太低都会使得强度和导电性性能降低.随中间热处理温度的升高,电阻率先减小后增加,强度较小地先增加后减小,只经过一次中间热处理的材料在500℃时,性能组合最佳.几个较好的电导率和极限抗拉强度组合为:82.8%IACS/791 MPa(Φ1 mm、B工艺)、80.6%IACS/809MPa(Φ1 mm、A工艺)和80.2%IACS/731MPa(Φ1.2 9 mm、A工艺),7 8.4%IACS/9 5 0 M Pa(Φ1 mm、C工艺).

The structure ,strength and electrical conductivity of Cu-10% Cr- 3% Ag in-situ composites obtained by cold drawing combined with intermediate heat treatments have been investigated. The structures of the in-situ composites were examined by SEM. The results indicate that in as-cast condition, the morphology of Cr were dendritic ; during deformation, Cr were drawn into fine ribbons and the Cr ribbons are curl and fold in cross-section. As the strain is increased, the ribbons became more fine and uniform. The tensile strengtla and electrical resistivity increase with increasing strain. Intermediate heat treatments have the effects on both the strength and the electrical resistivity. While the temperature of intermediate heat treatment is increased, the risistivity is decreasd first then increased with reverse trend as tensile strength. The optimum treatment temperature is 500℃ with the combinations of the electrical conductivity and the tensile strength given following： 82.8%IACS/791 MPa（Ф1 mm, B） ;80. 6% IACS/809 MPa（Ф1mm,A） ;80. 2% IACS/731 MPa（Ф1. 29 mm,A） and 78.4% IACS/950 MPa（Ф1 mm,C）.