晶体相场方法在纳米裂纹扩展与韧脆断裂领域的研究进展

进入21世纪，计算机数值模拟技术在科学研究中的作用越来越突出，它与实验观测、理论模型分析并称为20世纪以来的三大科学研究方法。本文首先简要介绍裂纹研究的现状和宏观断裂力学存在的尺度局限性，并对近年来发展的原子级空间分辨尺度的晶体相场(PFC)模拟方法所具有的特征尺度范围和特色，以及PFC模型在模拟纳观尺度的材料微结构演化上所具有的优势进行说明。然后，介绍PFC模型在裂纹研究上的主要应用成果，包括以下5个方面：Zener裂纹的形核与扩展、纳米裂尖楔形位错空隙发射、晶列取向对纳米裂纹扩展的韧-脆断裂影响、纳米裂纹扩展模式的分类、纳米孔洞裂纹的愈合修复。最后，总结并指出PFC模型的发展方向及其今后在裂纹研究领域应用的新领域和重点方向。

Application Progress of Phase Field Crystal Method in Study of Nano-Crack Propagation and Ductile-Brittle Fracture

In the 21st century,the role of computer numerical simulation technology in scientific research is becoming more and more prominent.It is known as the three major scientific research methods since the 20th century,together with experimental observation and theoretical model analysis.This article first briefly introduces the current situation of crack research and the scale limitations of macroscopic fracture mechanics,and explains the characteristic scale range and characteristics of the Phase Field Crystal (PFC) simulation method developed in recent years at the atomic level spatial resolution scale,as well as the advantages of the PFC model in simulating the microstructure evolution of materials at the nano-scale.Then,the main application results of PFC model in crack research are introduced,including the following five aspects:nano-Zener-crack nucleation and growth of cracks,emission of nano-wedge gap with dislocations from crack tip,effects of crystal column orientation on the ductile-brittle fracture of the crack extension,the classification of nano-hole-crack healing,nano-crack propagation mode.Finally,the development direction of PFC model and its new application fields and key directions in the field of crack research are summarized and pointed out.