铜基异构纳米金属多层膜变形机制与加工硬化行为研究

项目名称： 铜基异构纳米金属多层膜变形机制与加工硬化行为研究

项目编号： No.51201123

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 金属材料学科

项目作者： 张金钰

作者单位： 西安交通大学

项目金额： 25万元

中文摘要： 本项目拟在刚性基体上分别制备组元层厚度(h)相等、调制周期(λ)系列变化（λ = 2h = 4 ~ 400 nm）的晶体/晶体（FCC/BCC型Cu/Mo、FCC/HCP型Cu/Zr）和晶体/非晶（Cu/Cu-Zr）Cu基异构纳米金属多层膜，采用纳米压痕法和微纳柱体压缩法测定表征Cu基纳米金属多层膜硬度/强度的(应变)速率敏感性及其力学响应，系统研究不同特征尺寸、界面密度和异型结构下纳米多层膜力学性能与变形方式随加载条件变化规律，探索Cu基金属多层膜宏观塑性的微观机制及其加工硬化行为的物理本质，尝试定量描述多层膜的硬化行为并建立相关理论模型。通过与等厚度各组元材料单质膜的力学行为对比，澄清纳米多层膜中层厚变化引起的尺寸约束和界面密度变化引起的界面约束效应，并揭示纳米金属多层膜微观组织结构-约束效应-服役性能之间的关系。为设计高可靠性与高性能纳米器件和材料提供技术支撑。

中文关键词： 纳米金属多层膜；塑性变形；断裂行为；尺寸效应；界面效应

英文摘要： This project is focused on the systematic investigation of the plastic deformation and the work hardening behavior in Cu-based nanostructured metallic multilayers with different crystal structures. The nanostructured crystalline/crystalline (FCC/BCC Cu/Mo and FCC/HCP Cu/Zr) and crystalline/amorphous (Cu/Cu-Zr) multilayers with equal layer thickness (h) spanning from 2 to 200 nm will be prepared on Si substrate, respectively. The traditional nanoindentation tests and microcompression methodology will be used to investigate the (strain) rate sensitivity of hardness/strength and mechanical response of all the three types of Cu-based nanostructured multilayers. With these mechanical measurements, the effects of (intrinsic and extrinsic) size, hetero-phase interface density and crystal structure as well as the external loading conditions on the mechanical properties and deformation modes of Cu-based nanostructured multilayers could be revealed, which permit the exploration of the deformation mechanisms and the physics of work hardening in metallic multilayers. Combining these experimental findings, a phenomenological dislocation-based model will be constructed to better describe the work hardening behaviors in metallic multilayers. Compared with the mechanics of monolithic constituent films, it is also expected that

英文关键词： Nanostructured metallic multilayers；Plastic deformation；Fracture behavior；Size effects；Interface effects