A356覆层温度对AZ31/A356轧制复合板界面组织及力学性能的影响  

Effect of A356 Covering Plate Temperature on the Microstructure and Mechanical Properties of AZ31/A356 Composite Plate Fabricated by Cast Roll Bonding

作　　者：杨世杰 李元东[1,2] 曹驰[1,2] 董澎源 李嘉铭 李明[1] YANG Shijie;LI Yuandong;CAO Chi;DONG Pengyuan;LI Jiaming;LI Ming(State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals,Lanzhou University of Technology,Lanzhou 730050;Key Laboratory of Non-ferrous Metal Alloys and Processing,Ministry of Education,Lanzhou University of Technology,Lanzhou 730050)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [2]兰州理工大学有色金属合金及加工教育部重点实验室,兰州730050

出　　处：《材料导报》2019年第14期2397-2402,共6页Materials Reports

基　　金：国家自然科学基金(51464031);甘肃省重点研发计划(17YF1GA021)~~

摘　　要：采用铸轧法制备的镁/铝复合板,研究了A356铝合金覆层温度对界面组织及力学性能的影响。结果表明,镁/铝复合板界面过渡区可分为三个区域,靠近AZ31一侧可能形成了镁侧过渡区Ⅰ区(δ-Mg和Mg17Al12),靠近A356一侧可能形成了铝侧过渡区Ⅱ区(α-Al和Al3Mg2),以及扩散界面中间区Ⅲ区(Mg17Al12、Mg2Si和Al3Mg2)。随着A356覆层温度的升高,界面过渡区的宽度持续增加,且金属间化合物的种类增多、体积分数增大。界面过渡区的显微硬度比基体的高,剪切实验时易在脆性相处发生断裂,靠近AZ31一侧为解理断裂,靠近A356一侧为准解理断裂,均为脆性断裂。A356覆层温度为640℃时,复合板的剪切强度达到最大值,为108MPa。The present work aims to investigate the effects of A356 covering plate temperature on interfacial microstructure and mechanical properties of the cast-rolled Mg/Al composite plate.The results indicate that the interfacial transition zone of Mg/Al can be divided into three regions:region I is adjacent to Mg and may form Mg transition region(δ-Mg and Mg 17 Al 12),region II is adjacent to Al and may form Al transition region(α-Al and Al 3Mg 2),region III is regarded as the diffusion interfacial intermediate region(Mg 17 Al 12,Mg 2Si and Al 3Mg 2).The increasing temperature of the A356 covering plate results in a continuous rise of the width of the interfacial transition zone,and also the increment of type and volume fraction of the intermetallic compounds.Microhardness in the interfacial transition zone is higher than that of the matrix.It is easy to observe the phenomenon of brittle fracture along the brittle phase during the shear strength test.There occur cleavage fracture and quasi-cleavage fracture,both of which are brittle fracture,at AZ31 side and A356 side,respectively.The shear strength of the composite plate reaches its maximum value of 108 MPa when the temperature of the A356 covering plate is 640℃.

关 键 词：镁/铝复合板 力学性能 界面过渡区 金属间化合物 

分 类 号：TG335.81[金属学及工艺—金属压力加工]