Hot deformation and processing maps of as-sintered CNT/Al-Cu composites fabricated by flake powder metallurgy  

片状粉末冶金烧结态CNT/Al-Cu复合材料的热变形及加工图（英文）

作　　者：Chun-hong LI Ri-sheng QIU Bai-feng LUAN Wei-jun HE Zhi-qiang LI 李春红;邱日盛;栾佰峰;何维均;李志强(重庆大学材料科学与工程学院,重庆400044;重庆科技学院冶金与材料工程学院,重庆401331;上海交通大学材料科学与工程学院,上海200240)

机构地区：[1]College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China [2]College of Metallurgy and Materials Engineering,Chongqing University of Science and Technology,Chongqing 401331,China [3]School of Materials Science and Engineering,Shanghai Jiaotong University,Shanghai 200240,China

出　　处：《Transactions of Nonferrous Metals Society of China》2018年第9期1695-1704,共10页中国有色金属学报（英文版）

基　　金：Project(KJ1601321)supported by Scientific and Technological Research Program of Chongqing Municipal Education Commission,China;Project(cstc2017jcyjAX0378)supported by the Chongqing Research Program of Basic Research and Frontier Technology,China

摘　　要：The deformation behaviors of as-sintered CNT/Al-Cu composites were investigated by isothermal compression tests performed in the temperature range of 300-550°C and strain rate range of 0.001-10 s-1 with Gleeble 3500 thermal simulator system.Processing maps based on dynamic material model(DMM)were established at strains of 0.1-0.6,and microstructures before and after hot deformation were characterized by scanning electron microscopy(SEM),electron backscatter diffraction(EBSD)and high-resolution transmission electron microscopy(HRTEM).The results show that the strain has a significant influence on the processing maps,and the optimum processing domains are at temperatures of 375-425°C with strain rates of 0.4-10 s-1 and at 525-550°C with 0.02-10 s-1 when the strain is 0.6.An inhomogeneous distribution of large particles,as well as a high density of tangled dislocations,dislocation walls,and some sub-grains appears at low deformation temperatures and strain rates,which correspond to the instability domain.A homogeneous distribution of fine particles and dynamic recrystallization generates when the composites are deformed at 400 and 550°C under a strain rate of 10 s-1,which correspond to the stability domains.采用Gleeble-3500热模拟试验机在温度300~550°C、变形速率0.001~10 s-1条件下,对片状粉末冶金烧结态CNT/Al-4Cu复合材料进行热变形行为研究。基于动态材料模型(DMM)建立应变为0.1~0.6的加工图,并利用扫描电镜、电子背散射衍射技术和高分辨透射电镜分析变形前后的显微组织。结果表明:应变对加工图有明显的影响,当应变为0.6时,最优加工区域为:375~425°C,0.4~10 s-1和525~550°C,0.02~10 s-1。在低变形温度和低变形速率时,基体中大颗粒不均匀分布,出现高密度缠结位错、位错墙和亚晶,对应加工图中的不稳定区域。当变形温度为400°C和550°C、变形速率为10s-1时,基体中细小颗粒均匀分布,晶粒为再结晶形态,对应加工图中的稳定区域。

关 键 词：CNT/Al-Cu composites flow stress processing map dynamic recrystallization 

分 类 号：TF125[冶金工程—粉末冶金] TB333[冶金工程—冶金物理化学]