铝锂合金的疲劳裂纹扩展行为及耐疲劳损伤机理

Fatigue crack growth behavior and fatigue damage resistance mechanism of Al-Li alloy

本文综述了铝锂合金疲劳裂纹扩展特性及耐疲劳损伤机理。在阐述铝锂合金不同类型时效析出相强化机理(切过机制和绕过机制)的基础上,详细论述了时效过程中析出相演化对铝锂合金疲劳裂纹扩展(FCG)速率的影响及机理,并重点阐述了晶粒组织(包括再结晶程度、晶界密度、晶粒尺寸、晶粒取向等)对铝锂合金FCG速率的影响及机理。总结了第三代耐疲劳损伤铝锂合金的开发路径、成分组织设计思路及部分铝锂合金的FCG性能;在阐述国内与国际上耐疲劳损伤铝锂合金发展差距的基础上,提出了国内耐疲劳损伤铝锂合金的研究方向。

The fatigue crack growth(FCG)features and fatigue damage resistance mechanism of Al-Li alloys were summarized.Based on the description of precipitation strengthening mechanism(shearing mechanism and by-passing mechanism),the FCG rate dependences of Al-Li alloys on precipitate evolution were expounded in detail.The effects of grain structures(recrystallization degree,grain boundary density,grain size and grain orientation)on their FCG rates were then emphatically discussed.The exploitation approach,composition and microstructure design ideas,FCG properties of the 3rd generation fatigue damage resistant Al-Li alloys were summarized.On the comments of the development gap of domestic and international fatigue damage resistant Al-Li alloys,the future research on damage resistant Al-Li alloys in China was proposed.