Cu-Zn合金組織性能的影響
(中南大學(xué) 材料科學(xué)與工程學(xué)院, 長(zhǎng)沙 410083)
摘 要: 用中頻熔煉-半連續(xù)鑄錠技術(shù)制備了一種成分為Cu-2Zn-0.6Cr的合金, 鑄錠經(jīng)熱擠壓成28 mm×8 mm的條材并進(jìn)行在線水淬, 之后對(duì)條材分別實(shí)施時(shí)效和冷拉變形-時(shí)效兩種處理, 冷拉變形量為35%。 測(cè)試了合金的拉伸力學(xué)性能和電學(xué)性能, 用金相、 X射線衍射和電子顯微分析研究了不同處理態(tài)合金的微觀組織結(jié)構(gòu)及其變化。研究結(jié)果表明： 研究合金有很強(qiáng)的時(shí)效強(qiáng)化效應(yīng)和優(yōu)良的中溫特性； 時(shí)效前的預(yù)泠變形可以顯著提高合金的強(qiáng)度, 強(qiáng)度增量達(dá)到130 MPa； 這種合金最佳的形變熱處理工藝為在線固溶-35%冷拉變形-450 ℃下時(shí)效4 h, 在此條件下合金抗拉強(qiáng)度和屈服強(qiáng)度分別達(dá)到467 MPa和390 MPa, 延伸率和電導(dǎo)率分別達(dá)到20.8%和64.5%IACS。 顯微組織結(jié)構(gòu)分析結(jié)果表明, 形變熱處理狀態(tài)的合金力學(xué)性能和電學(xué)性能由時(shí)效過(guò)程中的回復(fù)-再結(jié)晶和時(shí)效析出兩個(gè)過(guò)程控制, 合金的高強(qiáng)度主要來(lái)源于預(yù)冷變形引起的亞結(jié)構(gòu)強(qiáng)化和Cr粒子的析出強(qiáng)化。
關(guān)鍵字: 銅合金; Cr合金化； 形變熱處理; 組織; 力學(xué)性能
of Cu-Zn alloy by minor Cr alloying
ZHANG Sheng-long, LI Xue, SUN Wei
（School of Materials Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: An Cu-2Zn-0.6Cr alloy was prepared using intermediate frequency melting and semi-continuous casting. The ingots were extruded into bands with dimension of 28 mm×8 mm which were then immediately immersed into water. The extrusion ratio was 15∶1. After extrusion, the bands were 35% cold-drawn and then aged under different conditions. The effects of aging temperature and time on mechanical and electrical properties of the alloy, which were processed using solution-aging and solution -35%cold drawing-aging, respectively, were studied. The results show that, firstly, the alloy has strong aging strengthening effect and good performance at intermediate temperature; secondly, cold-drawing prior to aging can significantly increase the strength of the alloy; thirdly, the optimum treatment is proved to be solution treatment followed by 35% cold-drawing and then aged at 450 ℃ for 4 h, under which the tensile strength, yield strength, elongation and electrical conductivity of 467 MPa, 390 MPa, 20.8% and 64.5 %IACS, respectively, were obtained. It is shown that the properties of the alloy are controlled by reversion-recrystallization and precipitation during the aging process. Substructure strengthening due to cold-drawing deformation and precipitation strengthening by the Cr particles precipitation are responsible for the high strength of the studied alloy.
Key words: Cu-Zn alloys; Cr alloying; thermomechanical heat treatment; microstructures; mechanical properties
