TC4ELI合金显微组织对疲劳裂纹扩展速率的影响  

Effects of Microstructure on Fatigue Crack Propagation Rate of TC4ELI Alloy

作　　者：万明攀[1] 伍玉娇[1] 徐平伟[1] 

机构地区：[1]贵州大学材料与冶金学院贵州省材料结构与强度重点实验室,贵州贵阳550003

出　　处：《热加工工艺》2012年第16期20-22,共3页Hot Working Technology

基　　金：贵州科学技术基金项目([2011]2009号);贵阳市科学技术局项目(第1-046号)

摘　　要：研究了TC4ELI钛合金的片层组织和等轴组织的疲劳裂纹扩展性能,通过金相显微镜观测了疲劳裂纹在组织中的扩展途径,采用扫描电镜观察了疲劳断口的形貌,并讨论了显微组织对该合金抵抗疲劳裂纹扩展性能的影响。结果表明:TC4ELI合金经995℃×1hAC+550℃×4hAC处理后得到片层组织抵抗裂纹扩展的性能优于经900℃×1hAC+550℃×4 hAC处理后得到的等轴组织性能。从断口观察可知,断裂主要是以疲劳条带扩展机制为主,同时也存在微区解理断裂机制。The fatigue crack propagation properties of TC4 ELI alloy with equiaxed and lamellae microstructure were studied.The mechanisms of crack propagation were studied by OM and SEM.The effects of microstructure of TC4 ELI alloy on the fatigue crack propagation rate were discussed.The results show that the microstructure of TC4 ELI alloy after 995 ℃ × 1 hAC ＋ 550 ℃× 4 hAC is lamella microstructure,which has higher fatigue crack propagation resistance compared with the equiaxed microstructure after 900 ℃× 1 hAC＋550 ℃× 4 hAC.The cracks growth region are mainly in the form of strip mechanism in the stable spread region with some behaviors of micro-cleavage fracture by observing fatigue fracture morphology.

关 键 词：TC4ELI合金 显微组织 疲劳裂纹扩展速率 断口 

分 类 号：TG113[金属学及工艺—物理冶金]