材料期刊网

三维X射线衍射技术(3DXRD)是一种新兴的、先进的材料表征技术.该技术应用高能同步辐射X射线,可以表征块体材料的三维晶体结构和应力状态.同时测量是无损的,因此可以应用这一技术跟踪材料内部的微观组织随时间的演化(也就是四维的结构表征).高强度同步辐射X射线还保证了能够对材料内部微米级结构的衍射信息进行快速、准确地测量.这一技术最早由前丹麦国家实验室材料研究部以及欧洲同步辐射研究中心(ESRF)共同研究开发.几年之后,美国橡树岭国家实验室和美国先进光子源(APS)研究开发了另外一类3DXRD技术.目前已经可以在几个大型的同步辐射中心应用3DXRD技术,例如ESRF、APS和日本的Spring-8.综述了3DXRD技术的由来、基本原理、技术指标,以及该技术在金属材料研究中的几个应用实例.最后简要介绍该技术的最新研究进展,并对其未来在材料科学研究中的应用前景进行了展望.

The three-dimensional X-ray diffraction (3DXRD) is a new,advanced technique for materials characterization.This technique utilizes high-energy synchrotron X-rays to characterize the 3D crystallographic structure and strain/stress state of bulk materials.As the measurement is non-destructive,the microstructural evolution as a function of time can be followed,i.e.it allows 4D (x,y,z characterizations,t).The high brilliance of synchrotron X-rays ensures that diffraction signals from volumes of micrometer scale can be quickly detected and distinguished from the background noise,i.e.its spatial resolution can be micrometer scale and the measurement can be conducted within a reasonable time frame (a few hours).The 3DXRD microscope has originally been developed in cooperation between former Ris(o) National Laboratory and the European Synchrotron Radiation Facility.Currently,this technique has been implemented in several large synchrotron facilities,e.g.the Advanced Photon Source (APS) in USA and the Spring-8 in Japan.Another family of 3DXRD technique that utilizes white beam synchrotron X-rays has also been developed in parallel in cooperation between Oak Ridge National Laboratory and APS.This article reviews the 3DXRD technique.The content includes the idea behind the technique,the principle and specification (spatial, angular,temporal resolutions and sample environment etc.) of the technique.Several applications of the techniques in metallurgy are given,including: grain-scaled stress analysis during tensile deformation,recrystallization growth kinetics,recrystallization nucleation,growth of individual recrystallized grain,grain growth after recrystallization,and local residual strain/stress analysis.The recent development of the 3DXRD technique and its potential use for materials science in the future will be briefly discussed at the end.