摘要
对TC4钛合金电子束焊接四种典型熔凝区形状(钉形、漏斗形、楔形和钟罩形)焊接接头的微观组织进行了观察分析,并采用多晶局域梯度模型表征焊缝组织不均匀性,通过疲劳实验,建立焊接接头的组织不均匀性和疲劳性能的关系。结果表明:焊缝上端纵向柱状晶长度尺寸梯度变化较大的楔形形貌焊接接头疲劳寿命较低,梯度变化较小的钟罩形焊缝形貌接头疲劳寿命较高;疲劳裂纹多萌生于横向区域硬度梯度变化较大的热影响区和熔合线区域。
Local gradient simulation technology was used as a new method to describe the microstructure heterogenicity of TC4 weld joints,by observing the microstructure,testing the dimension of columnar grains,the lateral microhardness and conducting the fatigue experiment.The results show that the heterogenicity of the microstructure has an influence on the fatigue property of the weld joints.Fatigue life of the bell shaped weld joint with relatively homogeneous microstructure is higher than the wedge shaped weld joint with heterogeneous microstructure.The initiation of fatigue cracks is in the HAZ and the fusion line,where have high gradient of the lateral microhardness.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2010年第1期62-68,共7页
Journal of Materials Engineering
关键词
TC4钛合金
电子束焊接
多晶局域梯度模型
疲劳
TC4 alloy
electron beam welding
local gradient simulation teehnology
fatigue property
