块体非晶合金层裂微损伤演化行为表征

项目名称： 块体非晶合金层裂微损伤演化行为表征

项目编号： No.11272328

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 凌中

作者单位： 中国科学院力学研究所

项目金额： 90万元

中文摘要： 非晶合金层裂特性是其重要冲击拉伸性能之一。尽管已经获知Zr基块体非晶合金冲击载荷下层裂是在百纳秒内纳微米量级微孔洞成核、长大和连接所致，但是定量表征非晶合金层裂微孔洞演化行为研究少见报道。考虑到层裂行为依赖微结构效应而且率相关，演化过程中微孔洞成核、长大、连接与材料的微结构效应及变形机制密切相关，本工作拟基于层裂微孔洞成核、长大演化的物理过程，基于非晶合金特有的纳微结构本征响应，探索Zr基块体非晶合金层裂微孔洞成核、长大演化机制，建立适宜描述非晶合金层裂微孔洞成核、长大演化模型并获得微孔洞成核、长大规律；对非晶合金层裂涉及到原子分子层面、与非晶合金特有微结构以及微结构缺陷直接关联的微孔洞演化行为进行数值模拟表征。 通过对非晶合金层裂微孔洞演化行为的定量表征揭示冲击载荷下非晶合金层裂微孔洞演化诱致材料破坏的物理内涵、全面理解认识非晶合金层裂特性以及非晶合金室温下拉伸断裂机理。

中文关键词： 非晶合金；平板撞击实验；微损伤演化；内秉微缺陷；分子动力学模拟

英文摘要： Spallation is one of the most important dynamic failure modes for amorphous alloys. Though the process of nucleation, growth and coalescence of nano- and micro-voids within hundreds of nanoseconds is known to be the principle mechanism in spallation of the material under shock loading, studies on quantitatively characterization of the evolution behavior of microvoids were rarely reported. As the fact that spallation is a rate- and microstructure- dependent microdamage evolution process, this work will focus on several areas about spallation in Zr-based bulk amorphous alloys as follows: based on the physical observation on the process of nucleation, growth of microvoids, and the intrinsic response of unique microstructures in amorphous alloys, the mechanism of nucleation and growth of microvoids will be revealed, and proper models will be developed to characterize the microvoids' nucleation and growth processes; numerical simulations will be carried out to studied the effects of microstructures and micro defects during the microvoids evolution process in nanoscale and atomic scale. Via quantitatively characterization on microvoids evolution process in spallation of Zr-based bulk amorphous alloys, the physical mechanism will be revealed for understanding the material's failure process under shock loading. Finally

英文关键词： amorphous；plate impact experiment；microdamage evolution；intrinsic defects；MD simulation