摘要
采用Kahn撕裂法测试了高强度Al-Cu-Li合金2090在不同时效制度下的断裂韧性及其变化规律,并借助TEM和SEM对相应微观组织形貌及断口形貌进行了观察。结果表明:双级时效和应变时效均可促进T_1相析出,改善合金的断裂韧性,但这种促进作用在过时效状态下减弱;晶界PFZ的宽化和粗大晶界平衡相的析出降低合金的断裂韧性,并对时效工艺、微观组织及断裂韧性之间的关系进行了讨论。
The fracture toughn tested by utilizing ＂ Kahn method＂ ess of high strength Al - Cu - Li alloy 2090 under different aging conditions is i. e. , ＂ tear-to-failure＂ method. The microstructure and fractography for corresponding specimens are investigated by means of TEM and SEM observations. It is found that both double aging and strain aging promote the precipitation of T1-phase and hence improve the fracture toughness. However, under over aging condition, this promotion is weakened and the fracture toughness is coarsening of equilibrium phases along grain boundaries. The correlativi as aging condition is discussed in detail. sharply decreased due ty of fracture toughness
出处
《宇航材料工艺》
CAS
CSCD
北大核心
2007年第2期66-69,共4页
Aerospace Materials & Technology
关键词
铝锂合金
热处理
断裂韧性
微观组织
Al -Li alloys, Heat treatment, Fracture toughness, Microstructure to widening of PFZ and , microstructure as well
