Fatigue crack growth of titanium alloy joints by electron beam welding

作     者：Hong-Yu Qi Hao Shi Shao-Lin Li Xiao-Guang Yang 

作者机构：School of Jet Propulsion Beijing University of Aeronautics and Astronautics 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2014年第33卷第5期

页      面：516-521页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 

基　　金：financially supported by the Hi-Tech Research and Development Program (863) of China (No. 2012AA052102) Program of International Science and Technology Cooperation of China (No. 2013DFA61590) the National Natural Science Foundation of China (No. 51275023) 

主　　题：Microforming Ti–6Al–4V alloy Electron beam welding Fatigue crack growth Fracture analysis 

摘      要：Electron beam welding（EBW） has been widely used in the manufacture of titanium alloy welded blisk for aircraft engines. Based on fatigue crack growth tests on titanium alloy electron beam welding（EBW） joints, mechanism of fracture was investigated under scanning electron microscope（SEM）. The results show that fatigue crack growth rate increases as the experimental load increases under the same stress ratio and stress intensity factor range. At the beginning of crack growth, the extension mechanism of fatigue crack is the typical mechanism of cleavage fracture. In the steady extention stage, crack extends along the weld seam ***, crack growth direction changes to extend along the base metal. The extension mechanism of fatigue crack in the weld seam is the main mechanism of cleavage fracture and the extension mechanism of fatigue crack in the base metal is the main extension mechanism of fatigue band. In the instantaneous fracture stage, the extension mechanism of fatigue crack is the typical dimple-type static fracture *** growth was simulated by conventional finite element method and extended finite element method.