Simulation of Intergranular Ductile Cracking in β Titanium Alloys Based on a Micro-Mechanical Damage Model

Materials

Huang Yuan¹  Jinshan Li²  Jiangkun Fan²  Huan Li²  Bin Tang² 

[1] School of Aerospace Engineering, Tsinghua University, Beijing 100081, China;State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China;

关键词: intergranular crack propagation;    β titanium alloys;    micro-mechanical damage model;    ductile fracture;    fracture toughness;   

DOI  :  10.3390/ma10111250

来源: DOAJ

【 摘 要 】

The intergranular crack propagation of the lamellar structureβtitanium alloys is investigated by using a modified Gurson-type damage model. The representative microstructure of the lamellar alloy, which consists of the softαphase layer surrounding the hard grain interiors, is generated based on an advanced Voronoi algorithm. Both the normal fracture due to void growth and the shear fracture associated with void shearing are considered for the grain boundaryαlayer. The individual phase properties are determined according to the experimental nanoindentation result and the macroscopic stress–strain curve from a uni-axial tensile test. The effects of the strain hardening exponent of the grain interiors and the void shearing mechanism of the grain boundaryαlayer on fracture toughness and the intergranular crack growth behavior are emphatically studied. The computational predictions indicate that fracture toughness can be increased with increasing the strain hardening ability of the grain interiors and void shearing can be deleterious to fracture toughness. Based on the current simulation technique, qualitative understanding of relationships between the individual phase features and the fracture toughness of the lamellar alloys can be obtained, which provides useful suggestions to the heat treatment process of theβtitanium alloys.

【 授权许可】

Unknown