(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 采用光学显微镜(OM)和透射电镜(TEM)观察和分析形变热处理对Cu-11Zn-0.5Cr合金显微组织的影响，并测定不同时效工艺合金的力学性能和电学性能。结果表明：合金最佳形变热处理工艺为热挤压-在线水淬-18%冷拉-(450 ℃，4 h)时效，经此最佳形变热处理工艺处理后其硬度、拉伸强度和相对电导率可分别达到128HB、385MPa和41.72%IACS。合金性能主要受时效过程中的时效析出过程和回复-再结晶过程控制。在时效过程中，基体内溶质原子析出形成细小弥散第二相造成析出强化，且第二相对电子的散射作用较溶质原子的弱，使得合金强度和电导率均增大。回复与再结晶使结构中的变形畸变及缺陷消除，使得合金强度减小而电导率增大。
关键字: Cu-Zn-Cr合金；形变热处理；组织；力学性能；导电性能
（School of Material Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effect of thermo-mechanical treatment on the microstructure of Cu-11Zn-0.5Cr alloy was investigated by optical microscopy(OM) and transmission electronic microscopy(TEM). The mechanical and electrical properties of Cu-Zn-Cr alloy after different aging treatment were tested. The results show that the optimum thermo-mechanical treatment of Cu-11Zn-0.5Cr alloy is hot extrusion-quenching on line-18% cold drawing-(450 ℃, 4 h) aging. Under the condition, the hardness, the tensile strength and the relative conductivity of 128 HB, 385 MPa and 41.72 %IACS, respectively, can be obtained. The analyzation of the microstructure shows that the mechanical and electrical properties of the alloy are determined by the precipitation and recovery-recrystallization during the aging process. During aging, fine dispersed secondary phases formed by the precipitation of solute atoms in matrix would cause precipitation strengthening, and the secondary phases possess weaker scattering effect on electrons than that of solute atoms, which can enhance the strength and conductivity of the alloy. Besides, deformation distortion and defects in structure are eliminated during the process of recovery and recrystallization, which reduces the strength but enhances the conductivity of the alloy.
Key words: Cu-Zn-Cr alloy; thermo-mechanical treatment; microstructure; mechanical property; electrical property
