循环镦压制备Mg-4.1Mg_2Si复合材料的组织和力学性能  

Microstructure and mechanical properties of Mg-4.1Mg_2Si composite processed by cyclic upsetting

作　　者：郭炜[1] 王德[1] 付远[1] 

机构地区：[1]江西省科学院应用物理研究所,江西南昌330096

出　　处：《轻合金加工技术》2017年第2期37-41,共5页Light Alloy Fabrication Technology

基　　金：国家自然科学基金(51404151;51374145);中国博士后科学基金(2014M561466);上海市博士后科研资助计划项目(14R21411000)

摘　　要：采用常规铸造方法制备了Mg-4.1Mg_2Si复合材料,并在400°C对复合材料进行1、2、3道次的循环镦压加工,研究循环镦压对其显微组织和力学性能的影响。结果表明,加工过程中基体施加的剪切应力使杆状Mg_2Si相破碎成小颗粒,分布更加均匀,复合材料的强度和塑性都获得提高;3道次后,复合材料的屈服强度和伸长率分别从铸态的69 N/mm^2和3.8%提高到84 N/mm^2和6.8%,室温拉伸断裂形式由解理脆性断裂转变为韧脆混合型断裂。Mg-4.1Mg2Si composite was fabricated by the conventional casting method. Cy- clic upsetting was applied to process the composite for one, two, and three passes at 400℃. The effect of cyclic upsetting on microstructure and mechanical properties were investigated after that. The results show that the rod-shaped Mg2Si phases are broken up into smaller par- ticles due to the shear stress inflicted by the matrix, and their distribution become more hom- ogeneous during processing. Both strength and ductility are enhanced. The yield strength and elongation are increased to 84 N/mm^2 and 6.8% after three passes from 69 N/mm^2 and 3.8% of the as-cast composite. The tensile fracture mode at room temperature transforms from the brittle cleavage fracture to the ductile and brittle fracture.

关 键 词：Mg-Mg2Si复合材料 Mg2Si颗粒 循环镦压 显微组织 力学性能 

分 类 号：TB333[一般工业技术—材料科学与工程]