基于大型激光装置的材料塑性变形行为微介观研究进展

Recent progress in micro-mesoscopic study of dynamics of plastic deformation based on large-scale laser facilities

微介观尺度下材料结构的实时演化行为是决定其动态力学性能的关键因素。大型激光装置作为集加载和诊断能力为一体的综合实验平台,为高温、高压、高应变率等极端条件下材料动态力学性能的微介观尺度研究提供了重要支撑。随着激光功率密度和脉冲整形能力的不断提升,实验所能探索的压力(10^1~10^3 GPa)及应变率(10^6~10^10 s^−1)范围不断突破;而利用激光打靶产生的高亮X射线脉冲作为探测源,建立动态衍射和成像技术,可以实现高空间和时间分辨率下材料塑性变形机制的实时原位研究。简要介绍了基于大型激光装置的原位微介观实验技术及其在材料塑性变形行为研究中的应用,系统梳理了近二十年来具有代表性的研究成果,阐明了相关研究对推动材料动态响应多尺度物理建模的重要价值。

The dynamic response of materials is strongly dependent on the temporal evolution of microstructures.As a comprehensive experimental platform integrating dynamic loading and in-situ diagnostic capability,large-scale laser facilities provide technical support to investigate micro-mesoscopic behaviors of materials under extreme conditions of high temperature,high pressure,and high strain rate.The use of high-power pulsed lasers to explore the response of materials under the pressure of tens of GPa up to several TPa,the time duration of nanoseconds,and the strain rate of 10^6−10^10 s^−1 is revealing novel mechanisms of plastic deformation and therefore strength evolution.This unique experimental tool,aided by advanced diagnostics,analysis,and characterization,including X-ray diffraction,absorption and imaging,allows us to make real-time observation on these new regimes with high spatial and temporal resolution.In this paper,we review the progress within the last 20 years in micromesoscopic dynamic probing techniques,based on large-scale laser facilities,and their applications in the study of dynamic plasticity and strength.At the end,we discuss the significance of these works to promote the multiscale modeling of the dynamic response of materials.