(東北大學(xué) 軋制技術(shù)及連軋自動化國家重點(diǎn)實(shí)驗(yàn)室，沈陽 110819)
摘 要: 利用掃描電鏡、透射電鏡、金相顯微鏡及顯微硬度儀等研究了Cu-Ni-Si合金在鑄態(tài)、熱軋態(tài)、固溶態(tài)、冷軋和時(shí)效態(tài)的顯微組織、晶粒取向及大小和析出相的演變過程，分析熱軋流程中各類組織及工藝狀態(tài)對合金性能的影響規(guī)律。結(jié)果表明：合金成分是影響枝晶偏析和再結(jié)晶程度的關(guān)鍵，熱軋后晶粒擇優(yōu)取向明顯，發(fā)生部分再結(jié)晶，晶格畸變程度增大，導(dǎo)電率明顯下降；隨著固溶溫度的升高和固溶時(shí)間的延長，合金抗拉強(qiáng)度、硬度和導(dǎo)電率均呈下降趨勢，合金經(jīng)900 ℃、1 h處理后達(dá)到最佳固溶效果， 晶界達(dá)到35.2%，大角晶界達(dá)到了64.4%，晶粒取向均勻；冷軋后，晶粒被拉長、撕碎，基體產(chǎn)生大量缺陷，為時(shí)效析出提供核心作用；冷軋變形量越大，時(shí)效析出動力越強(qiáng)，析出相越細(xì)小、均勻，綜合性能越好；合金在經(jīng)450 ℃、3 h處理后達(dá)到最佳時(shí)效效果，硬度為259HV，導(dǎo)電率為36.5%IACS。
關(guān)鍵字: Cu-Ni-Si合金；熱軋；再結(jié)晶；析出動力；顯微硬度；導(dǎo)電率
（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
