形变诱发纳米晶局域固态非晶化的研究进展

Research Progress of Deformation Induced Localized Solid-state Amorphization in Nanocrystalline Materials

形变诱发纳米晶金属材料局域固态非晶化转变是近年来提出的获得局域固态非晶化组织的一种新途径,这种转变机制使得以位错、变形孪晶、晶界滑动和晶粒转动为主要变形机制的纳米晶材料中可能存在一种全新的塑性变形机制,并且,局域固态非晶化的临界转变条件和转变机制可为材料的结构优化设计提供依据。概括了国内外实验及数值模拟手段关于形变诱发局域固态非晶化转变的研究,例如采用机械球磨、高压扭转变形、经典力场和分子动力学等方法,证明了形变诱发局域固态非晶化转变的存在。此外,还分析了发生局域固态非晶化转变的内在机制。基于晶体相场模型的优势,提出用该方法模拟局域固态非晶化转变的突出之处,表明了晶体相场法能够有效研究局域固态非晶化转变过程。

Localized solid-state amorphization(LSSA)transformation of nanocrystalline materials induced by mechanical deformation is proposed to obtain localized amorphous structure in recent years.This new method forms an entirely new plastic deformation mechanism in nanocrystalline materials with dislocation,deformation twinning,grain boundary slide and grain rotation as the main deformation mechanism.The critical transformation condition and the transition mechanism of the LSSA transformation provide a basis for the optimum structural design of materials.This paper summarizes the domestic and foreign experimental and simulative studies of deformation-induced LSSA transformation,such as mechanical ball milling,high-voltage torsional deformation,classical force field and molecular dynamics methods,which prove existence of the deformation-induced LSSA transformation.Also,the intrinsic mechanism of LSSA transformation is analyzed.Based on the advantages of the crystal phase field model,this method is proposed to simulate the LSSA transformation and the crystal phase field method can effectively study the LSSA transformation process.