温度对Mg-10Gd-2Y-0.5Zr合金动态拉伸行为及断裂机理的影响  

Effect of Temperature on the Dynamic Tensile Behavior and Fracture Mechanism of Mg-10Gd-2Y-0.5Zr Alloy

作　　者：纪伟[1] 范亚夫[1] 陈捷[1] 王军[1] 

机构地区：[1]中国兵器工业集团第52研究所烟台分所,山东烟台264003

出　　处：《材料工程》2009年第10期41-44,共4页Journal of Materials Engineering

摘　　要：利用带有加热装置的Hopkinson Bar拉伸系统在423-798K、应变率处于103s-1范围内研究了两种挤压态的Mg-10Gd-2Y-0.5Zr合金的拉伸行为,并借助光学显微镜和扫描电镜对试样断口附近的显微组织和断口形貌进行了分析。结果表明：T≤673K时,材料的破坏机理主要表现为浅韧窝与准解理的混合型断裂;随着温度的进一步升高由于受晶界软化的影响材料的断裂机理逐渐转向以晶间断裂为主。T〈673K时材料的主要变形机制是基面滑移,随着温度的升高非基面滑移系将充分启动,材料的延伸率也相应地在735K时达到最大值。The dynamic tensile behaviors of two kinds of Mg-10Gd-2Y-0.5Zr alloys were investigated using a high-temperature split Hopkinson Bar at 423-798K and strain-rate of about 10^3s^- 1. Microstructures adjacent to the fracture and morphologies were examined by optical microscope and scanning electron microscope. The results indicate that the fracture mechanism varies from the mixed mechanisms of shallow-dimples and quasi-cleavage fracture（T≤673K） to intergranular rupture（T≥ 735K） with increasing temperature. When T〈673K, the main deformation mechanism of the tensile samples are basal slip. In addition to basal slip, pyramidal slip and prismatic slip will be gradually activated with continually increasing temperature, which account for the maximum elongation of the samples tensioned at 735K.

关 键 词：Mg-Gd-Y系合金 高温 冲击拉伸 断口形貌 

分 类 号：TG146.2[一般工业技术—材料科学与工程]