(1. 重慶大學(xué) 材料科學(xué)與工程學(xué)院，重慶 400044；
2. 重慶西彭產(chǎn)業(yè)工業(yè)園區(qū)，重慶 401326)
摘 要: 通過Gleeble-3500熱模擬機(jī)在350~500？℃溫度范圍對2195鋁鋰合金進(jìn)行平面應(yīng)變壓縮實(shí)驗(yàn)，應(yīng)變速率為0.01~1？s-1，變形量60%。研究合金在高溫下的流變行為并通過背散射電子衍射(EBSD)和X射線衍射(XRD)揭示了微觀組織的演變規(guī)律。結(jié)果表明：流變應(yīng)力隨應(yīng)變速率的增加而升高，而隨著溫度的升高流變應(yīng)力降低，并且達(dá)到峰值應(yīng)力和穩(wěn)態(tài)流變時(shí)所需的應(yīng)變也減少，建立含有雙曲正弦關(guān)系的本構(gòu)方程并得到合金的變形激活能Q為278.208？kJ/mol；隨著Zener-Hollomon參數(shù)值的增加，合金的流變集中增加，合金的軟化機(jī)制主要是動(dòng)態(tài)回復(fù)，此外還有動(dòng)態(tài)再結(jié)晶形成，動(dòng)態(tài)再結(jié)晶主要為不連續(xù)動(dòng)態(tài)再結(jié)晶，而連續(xù)動(dòng)態(tài)再結(jié)晶和幾何動(dòng)態(tài)再結(jié)晶均容易在較低Z值和較高Z值下形成；變形組織中含有大量的軋制織構(gòu)，變形晶粒主要為S{123} 、Brass{011} 、Copper{112} 和Goss{011} 這4種取向。
關(guān)鍵字: 2195鋁鋰合金；平面應(yīng)變壓縮；流變行為；微觀組織
（1. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. Chongqing Xipeng Industrial Park, Chongqing 401326, China）
Abstract:Plane strain compression tests of AA2195 aluminum alloy were conducted on Gleeble-3500 system in the temperature range from 350 ℃ to 500 ℃ and at strain rate range from 0.01？s-1 to 1？s-1 with 60% thickness reduction. The flow behavior was studied in present work and the microstructure was revealed by electron backscatter diffractometry(EBSD) and X-ray diffractometry(XRD). The results show that the stress increases with the increase of strain rate whereas decreases with the increase of temperature, the peak strain and the critical strain for attaining steady state decreases with increasing temperature. A constitutive equation based on the hyperbolic sine equation is established with the deformation activation energy is calculated to be 278.208 kJ/mol. Flow localization increases with the increase of the value of Zener-Hollomon parameter, the basic softening mechanism is dynamic recovery(DRV), besides, dynamic recrystallization(DRX) occurs and is mainly discontinuous recrystallization(DDRX), continuous recrystallization(CDRX) and geometric recrystallization(GDRX) occurs more easily in lower Z value and higher Z value, respectively. Significant amounts of the major rolling texture components, namely, S{123} , Brass{011} , Copper{112} and Goss{011} are observed at deformed samples.
Key words: 2195 Al-Li alloy; plane strain compression; flow behavior; microstructure
