Void damage evolution of LF6 aluminum alloy welded joints under external load and thermal cycling co

• 作 者: 米国发 赵大为 董翠粉 牛济泰 金成
• 机 构: School of Materials Science and Engineering,Henan Polytechnic University,School of Materials Science
• 出 处: Transactions of Nonferrous Metals Society of China
• 发表日期: 2010年10期
• 关键词: welded joints cycling aerospace dislocation nucleation exceed reaches welding bo

Based on the simulated aerospace thermal cycling tests,the effect of thermal cycle on the void damage evolution mechanism of LF6 aluminum alloy welded joint was investigated.The results show that micro-voids form around the second phase particles under the thermal cycling tests.The thermal stress coupled with external stress leads to dislocations pile-up around the particles,and when the dislocation density reaches a certain degree,the stress concentration will exceed the bonding strength at the interface between particles and matrix,resulting in the formation of micro-cracks.The numerical simulation is successfully implemented with the finite element to describe the void damage evolution of the welded joint under thermal cycling conditions.

Based on the simulated aerospace thermal cycling tests, the effect of thermal cycle on the void damage evolution mechanism of LF6 aluminum alloy welded joint was investigated. The results show that micro-voids form around the second phase particles under the thermal cycling tests. Thermal stress coupled with external stress leads to dislocations pile-up around the particles, and when the dislocation density reaches a certain degree, the stress concentration will exceed the bonding strength at the interface between particles and matrix, resulting in the formation of micro-cracks. The numerical simulation is successfully implemented with the finite element to describe the void damage evolution of the welded joint under thermal cycling conditions.