宽幅AZ31B镁合金铸轧板显微组织和性能研究  

Study on Microstructure and Properties of the Broadloom AZ31B Magnesium Alloy Roll-casting Plate

作　　者：黄志权[1] 黄庆学[1] 马立峰[1,2] 林金保[1] 庞志宁[1] 

机构地区：[1]太原科技大学机械工程学院重型机械教育部工程研究中心,太原030024 [2]吉林大学超塑性与塑性研究所,长春130025

出　　处：《材料研究学报》2013年第3期292-298,共7页Chinese Journal of Materials Research

基　　金：国家自然科学基金(51105264;51204117);太原科技大学研究生科技创新项目20125002;国家重点基础研究发展计划2011CB612204资助项目~~

摘　　要：通过金相观测、断口扫描和力学性能测试等实验,研究了宽幅AZ31B镁合金铸轧板的组织分布,及其对板带边裂和力学性能的影响。结果表明:AZ31B镁合金铸轧板的组织主要由α-Mg基体、析出相β-Mg17Al12相及α+β离异共晶组成,呈树枝晶形貌;β-Mg17Al12相在AZ31B镁合金铸轧板坯的表层及边部主要分布于晶界处且密度较大、构成网状,而在板坯的心部和中部呈球状弥散于α-Mg基体中,构成层片状;在板坯边部枝晶间低熔点的共晶相及晶界上的β-Mg17Al12相易成为裂纹源,并沿晶向外扩展,是铸轧过程中产生裂纹的主要原因;试样拉伸断口呈脆性解理断裂的特征,其力学性能呈明显的各向异性。The microstructure of broadloom AZ31B magnesium alloy roll-casting plate and its influence on the edge crack and mechanical properties of the plate were studied by using metallographic observa- tion, SEM and mechanical property testing experiment. The results show that： the plate organization is mainly composed of α-Mg matrix, ,β-Mg17A12 phase and α ＋ β,8 divorced eutectic, showing dendritic mor- phology; In surface and edge of the plate, β-Mg17A12 phase is mainly distributed at the grain boundary and the density is bigger, formed net-shape; In center and central of the plate, spherical ,β-Mg17A12 phase is dispersed in α-Mg matrix, formed lamellar-shape; The main reason for the edge crack in the cast-roll- ing process is in the slab edge interdendritic low-melting eutectic phase and ,β-Mg17A12 phase of grain boundary which are easy to be crack source, and extend outward along the crystal; The tensile specimen showes brittle cleavage fracture characteristics, and its mechanical property is obvious anisotropy.

关 键 词：金属材料 微观组织 力学性能 边裂 AZ31B镁合金 铸轧宽板 

分 类 号：TG146.2[一般工业技术—材料科学与工程]