Cu-0.77Cr-0.078Zr-0.13Ag合金的微观组织及性能研究

Study on Microstructure and Properties of Cu-0.77Cr-0.078Zr-0.13Ag Alloy

采用扫描电镜、能谱分析、透射电镜微观检测以及力学、电学性能检测手段,研究了Cu-0.77Cr-0.078Zr-0.13Ag合金的微观组织演变及性能变化规律。结果表明,Cu-0.77Cr-0.078Zr-0.13Ag合金经热锻、时效、冷轧处理后合金的抗拉强度、导电率、伸长率分别为640 MPa、80.8%IACS、8%。铸态组织中存在尺寸较大的水滴状富Cr相和较小尺寸的颗粒状富Cr相,经热锻处理后富Cr相尺寸有所减小,以颗粒状和长条状分布,冷轧处理后晶粒沿轧制方向呈层状均匀分布,厚度300~500 nm,而富Cr相主要以颗粒状分布于晶粒内部和晶界处,其中晶界处分布较为密集,尺寸在300 nm以下。此外,Zr、Ag元素始终呈弥散分布于合金中,合金冷轧处理后基体中存在大量的位错缠结,纳米Cr相的晶体结构为fcc和bcc。

The microstructure evolution and properties of Cu-0.77Cr-0.078Zr-0.13Ag alloy under various processes were investigated by SEM, EDS, TEM. The results show that the tensile strength, electrical conductivity, and elongation of Cu-0.77Cr-0.078Zr-0.13Ag alloy after hot forging, aging, and cold rolling is 640 MPa, 80.8 % IACS and 8%, respectively. There are large drop-like Cr-rich phases and smaller size granular Cr-rich phases in the as-cast structure. The size of the Cr-rich phases reduces after hot forging, and distributed in granular and long strips. Cold rolling after treatment, the grains are uniformly distributed in the rolling direction, with the thickness of 300-500 nm. The Cr-rich phases are mainly distributed in the grains and at the grain boundaries in the form of granules, and the middle boundary is densely distributed and the size is below 300 nm. In addition, Zr and Ag elements are always dispersed in the alloy, large number of dislocation entanglement exists in the matrix after alloy cold rolling treatment, and the crystal structures of the nanoscale Cr phases are fcc and bcc.