等温压缩对钛合金TC4-DT组织及断裂韧性的影响  

Effects of Isothermal Compression on Microstructure and Fracture Toughness of TC4-DT Titanium Alloy

作　　者：彭小娜[1] 郭鸿镇[1] 石志峰[1] 姚泽坤[1] 

机构地区：[1]西北工业大学材料学院,陕西西安710072

出　　处：《热加工工艺》2011年第20期64-67,共4页Hot Working Technology

摘　　要：研究了不同温度等温压缩变形及热处理后对损伤容限型钛合金TC4-DT断裂韧性的影响,对比分析了各个温度下的显微组织与断裂韧性的关系,用扫描电镜对断口进行了观察。研究结果表明,两相区较低温度等温压缩变形得到等轴组织,较高温度得到双态组织;相变点以上得到片层组织,片状组织的断裂韧性高于等轴组织。4种温度的断口均为等轴韧窝型延性断裂,随着温度的升高,断面粗糙度增加,韧窝直径和深度逐渐下降,在片层组织中发现了二次裂纹。The influences of isothermal deformation at different temperature on fracture toughness of damage tolerance titanium alloy TC4-DT were studied.The microstructure and fracture toughness were compared and analyzed.The fracture surface was investigated by SEM.The results show that,when deformation is in the lower region of the two phase,equiaxial α phase can be obtained,while in the higher region,bi-modal microstructure can be acquired.The fracture toughness of lamellar microstructure is higher than that of equiaxial microstructure when deformed above the phase transition.The fracture at every temperature is equiaxed dimple-type ductile fracture.With the increase of temperature,the roughness of fracture surfaces increases and the diameter and depth of dimple decrease.Secondary cracks are observed in the lamellar microstructure.

关 键 词：损伤容限型钛合金 显微组织 TC4-DT 断裂韧性 

分 类 号：TG146.23[一般工业技术—材料科学与工程]