喷射成形AlSiCuMg合金的热变形组织演变及再结晶行为  

Microstructure Evolution and Recrystallization Behavior During Hot Deformation of Spray Formed AlSiCuMg Alloy

作　　者：吴彩虹 冯迪[1] 臧千昊 范诗春 张豪 李胤樹 WU Caihong;FENG Di;ZANG Qianhao;FAN Shichun;ZHANG Hao;LEE Yunsoo(School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003,China;Jiangsu Haoran Spray Forming Alloy Co.,Ltd.,Zhenjiang 212009,China;Metallic Materials Division,Korea Institute of Materials Science,Changwon 51508,Korea)

机构地区：[1]江苏科技大学材料科学与工程学院,镇江212003 [2]江苏豪然喷射成形合金有限公司,镇江212009 [3]Metallic Materials Division,Korea Institute of Materials Science,Changwon 51508,Korea

出　　处：《金属学报》2022年第7期932-942,共11页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目No.51801082;镇江市重点研发计划项目Nos.GY2021003和GY2021020;江苏省大学生创新创业计划重点领域项目No.202110289002Z;江苏省研究生科研与实践创新计划项目No.KYCX21_3453~~。

摘　　要：采用热压缩实验、SEM、TEM以及EBSD技术研究了喷射成形Al25Si4Cu1Mg(质量分数,%)合金的热变形组织演变规律及动态再结晶形核机制。结果表明:喷射态组织主要由等轴α-Al相、粗大块状Si相、AlSiCuMg相和不同尺度的Al_(2)Cu相构成。在623~723 K和0.001~5 s^(-1)条件下,细小的Al_(2)Cu相随形变温度的升高而逐渐回溶。高应变速率(5 s^(-1))热压缩时,位错塞积在粗大不溶初生相前沿产生应力集中,导致部分脆性初生相开裂,同时在初生相与α-Al相界面处出现局部裂纹。α-Al相则发生了完全动态再结晶。再结晶晶粒尺寸随着变形温度的下降和应变速率的提高而降低,晶粒内部的残留位错和形变亚结构随形变温度的升高而逐渐减少。随机织构表明,喷射成形Al25Si4Cu1Mg合金的动态再结晶机制为“粒子激发形核(PSN)”机制。Wrought Al-Si alloy has partially replaced the traditional wear-resistant alloy for structural weight reduction owing to the excellent comprehensive properties,such as wear resistance,low coefficient of thermal expansion,and high specific strength.The deformation aluminum alloy based on Al-Si bi-nary alloy is widely used in aerospace and automotive industries.The hot compression test,SEM,TEM,and EBSD technologies were used to investigate the microstructure evolution and dynamic recrystallization nucleation mechanism of spray formed Al25Si4Cu1Mg(mass fraction,%)alloy.The results show that the as-sprayed microstructure consists of equiaxedα-Al,coarse Si phase,AlSiCuMg phase,and Al_(2)Cu phase with different scales.Under 623-723 K and 0.001-5 s^(−1),the fine Al_(2)Cu phases gradually dissolve with the increase in deformation temperature.During high strain rate(5 s^(−1))compression,dislocation accumulation causes a high degree of stress concentration in front of the coarse and insoluble primary phases,resulting in the cracking of some brittle primary phases.Local cracks also appear at the interfaces betweenα-Al and primary phases.Theα-Al phase undergoes complete dynamic recrystallization.The recrystallized grain size decreases with the increase and decrease in strain rate and deformation temperature,respectively.The residual dislocation and deformation substructure in the grain decrease with the increase in deformation temperature.The random texture demonstrates that the dynamic recrystallization mechanism of spray formed Al25Si4Cu1Mg alloy is“particle stimulated nucleation(PSN)”.

关 键 词：AlSiCuMg合金 喷射成形 热压缩 粒子激发形核 动态再结晶 

分 类 号：TG146.2[一般工业技术—材料科学与工程]