摘要
采用Gleeble-3800热模拟机研究Al-8.9Zn-1.3Mg-0.1Sc-0.1Er-0.1Zr铝合金的热变形行为,构建温度380~440℃、应变速率0.01~10 s^(-1)区间内合金的热加工图,使用X射线衍射(XRD)、选区电子衍射(SAED)与能谱(EDS)对合金中存在的物相进行分析,并使用金相显微镜(OM)和透射电子显微镜(TEM)观察合金热变形后的微观组织。结果表明:合金的最佳热加工工艺参数区间为:400℃<T<440℃,0.01 s^(-1)<ε<0.1 s^(-1)。变形后合金的主要相组成为α-Al和Al_(3)(Sc,Er);塑性变形所需的应力随温度的升高和应变速率的降低而减小,主要是由于再结晶的发生和Al_(3)(Sc,Er)粒子钉扎力的减小;低应变速率下,发生动态软化的倾向更大,软化机制由动态回复转变为动态再结晶;绝热剪切带与位错塞积的形成是导致合金失稳的主要原因。
The hot deformation behavior of Al-8.9Zn-1.3Mg-0.1Sc-0.1Er-0.1Zr aluminum alloy was studied by Gleeble-3800 thermal simulator.The hot processing map of the alloy in the temperature range of 380-440℃and strain rate range of 0.01-10 s^(-1) was established.The phase in the alloy was analyzed by XRD,SAED and EDS.The microstructure after hot deformation was observed by OM and TEM.The optimum range of hot working parameters is as follows:400℃<T<440℃,0.01 s^(-1)<ε<0.1 s^(-1).The main phase group of the alloy after deformation isα-Al and Al_(3)(Sc,Er);The results show that the stress required for plastic deformation decreases with the increase of temperature and the decrease of strain rate,which is mainly due to the recrystallization and the decrease of pinning force of Al_(3)(Sc,Er)particles;the tendency of dynamic softening is greater at low strain rate,and the softening mechanism is changed from dynamic recovery to dynamic recrystallization;the formation of adiabatic shear band and dislocation stacking is the main reason for the instability of the alloy.
作者
汤中英
邢清源
杨守杰
丁宁
TANG Zhongying;XING Qingyuan;YANG Shoujie;DING Ning(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Beijing Advanced Engineering and Application Research Center of Aluminum Materials,Beijing 100095,China;The Sixth Military Representative Office in Beijing,Beijing 100095,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2022年第3期131-137,共7页
Journal of Materials Engineering
