(东北大学 轧制技术及连轧自动化国家重点实验室，沈阳 110819)
摘 要: 利用扫描电镜、透射电镜、金相显微镜及显微硬度仪等研究了Cu-Ni-Si合金在铸态、热轧态、固溶态、冷轧和时效态的显微组织、晶粒取向及大小和析出相的演变过程，分析热轧流程中各类组织及工艺状态对合金性能的影响规律。结果表明：合金成分是影响枝晶偏析和再结晶程度的关键，热轧后晶粒择优取向明显，发生部分再结晶，晶格畸变程度增大，导电率明显下降；随着固溶温度的升高和固溶时间的延长，合金抗拉强度、硬度和导电率均呈下降趋势，合金经900 ℃、1 h处理后达到最佳固溶效果， 晶界达到35.2%，大角晶界达到了64.4%，晶粒取向均匀；冷轧后，晶粒被拉长、撕碎，基体产生大量缺陷，为时效析出提供核心作用；冷轧变形量越大，时效析出动力越强，析出相越细小、均匀，综合性能越好；合金在经450 ℃、3 h处理后达到最佳时效效果，硬度为259HV，导电率为36.5%IACS。
关键字: Cu-Ni-Si合金；热轧；再结晶；析出动力；显微硬度；导电率
（State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China）
Abstract:Using SEM, TEM, OM and microhardness tester, the evolution of microstructure, grain orientation, size and precipitated phase of Cu-Ni-Si alloys in hot-rolling process during casting, hot rolling, solid solution, cold rolling and aging were studied. Meanwhile, the effect of microstructure and process state on properties were analyzed. The results show that the key to influence the degree of dendrite segregation and recrystallization is alloy composition. After hot rolling, the preferential orientation of the grain is obvious, and some recrystallization will occur. Meantime, due to the degree of lattice distortion increase, the conductivity decreases obviously. With the increase of solution temperature and the prolongation of time, the tensile strength, microhardness and conductivity of Cu-3.2Ni-0.75Si alloy decrease. The best solution effect is achieved at 900 ℃, 1 h, while the grain boundary reaches 35.2% and the large angle grain boundary reaches 64.4%, and the grain orientation is uniform. After cold rolling, the grains are torn, elongated, and the matrix produces a large number of defects, which provide the core for aging precipitation. The larger for rolling reduction, the stronger the precipitation force, and the finer the precipitated phase, of course, the better the comprehensive performance. The alloy has the best aging effect at 450 ℃, 3 h, with hardness of 259HV, and electrical conductivity of 36.5% IACS.
Key words: Cu-Ni-Si alloy; hot rolling; recrystallization; precipitating force; microhardness; electrical conductivity
