Damage prediction for magnesium matrix composites formed by liquid-solid extrusion process based on finite element simulation
A damage prediction method based on FE simulation was proposed to predict the occurrence of hot shortness cracks and surface cracks in liquid-solid extrusion process.This method integrated the critical temperature criterion and Cockcroft & Latham ductile damage model,which were used to predict the initiation of hot shortness cracks and surface cracks of products,respectively.A coupling simulation of deformation with heat transfer as well as ductile damage was carried out to investigate the effect of extrusion temperature and extrusion speed on the damage behavior of Csf/AZ91D composites.It is concluded that the semisolid zone moves gradually toward deformation zone with the punch descending.The amplitude of the temperature rise at the exit of die from the initial billet temperature increases with the increase of extrusion speed during steady-state extrusion at a given punch displacement.In order to prevent the surface temperature of products beyond the incipient melting temperature of composites,the critical extrusion speed is decreased with the increase of extrusion temperature,otherwise the hot shortness cracks will occur.The maximum damage values increase with increasing extrusion speed or extrusion temperature.Theoretical results obtained by the DeformTM-2D simulation agree well with the experiments.
magnesium matrix composite liquid-solid extrusion hot shortness cracks surface cracks finite element method
QI Le-hua LIU Jian GUAN Jun-tao SU Li-zheng ZHOU Ji-ming
School of Mechatronic Engineering, Northwestern Polytechnical University, Xian 710072, China;Key La School of Mechatronic Engineering, Northwestern Polytechnical University, Xian 710072, China
国际会议
北京
英文
1737-1742
2010-09-16（万方平台首次上网日期，不代表论文的发表时间）