缺口半径对Ti-55531合金全片层组织拉伸性能的影响  

Tensile Properties of Ti-55531 Titanium Alloy with Fully Lamellar Microstructure with Different Notch Radius

作　　者：王凤梅 黄朝文[1,2] 雷旻 万明攀[1,2] 温鑫[1] Wang Fengmei;Huang Chaowen;Lei Min;Wan Mingpan;Wen Xin(National&Local Joint Engineering Laboratory for High-Performance Metal Structure Materials and Advanced Manufacturing Technology,College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China;Key Laboratory for Material Structure and Strength of Guizhou Province,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学材料与冶金学院高性能金属结构材料与先进制造技术国家地方联合工程实验室,贵州贵阳550025 [2]贵州大学贵州省材料结构与强度重点实验室,贵州贵阳550025

出　　处：《稀有金属》2022年第10期1269-1277,共9页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51801037);贵州省科技计划项目(黔科合基础[2020]1Y196,黔科合平台人才[2018]5781号);贵州省教育厅青年科技人才成长项目(黔教合KY字[2018]104);贵州大学引进人才项目(贵大人基合字(2017)02号)资助

摘　　要：通过改变退火温度获得了Ti-55531合金不同组织参数的全片层组织,利用带有不同缺口半径(R=0.13,0.25 mm)和光滑试样的拉伸实验测试了合金的缺口拉伸性能,通过不同的缺口拉伸性能计算其缺口敏感系数(NSR),研究了缺口半径对合金全片层组织的拉伸性能的影响规律,采用扫描电镜(SEM)分析了合金组织参数和断口形貌特征,研究了该合金的拉伸断裂机制。结果显示,随退火温度的升高,α片和α集束的尺寸都增大,导致光滑试样的强度降低,塑性升高。虽然缺口对合金的拉伸性能有显著的影响,但该合金没有表现出“缺口强化”效应(NSR皆小于1),与光滑试样相比,缺口使合金塑性明显下降且强度也降低。另外,随退火温度的升高,合金的缺口敏感系数增大;随缺口半径的增加,合金抗拉强度略有增加,但塑性几乎不变,且都很低。合金的拉伸断裂方式是沿晶断裂、韧窝和解理开裂组成的混合断裂模式,缺口的存在使合金的脆断倾向增加。In recent years,high strength and toughness titanium alloy had become the object of many researchers because of its excellent performance in aerospace industry,and some of Ti-55531 alloy had been used to make the linkage between the wing and suspension slant of the Airbus-380.With the development of modern aviation aircraft in the direction of high speed and high maneuverability,the reliability and long life of high sight and thoroughness was more attentional of titanium alloy structural parts.Aerospace components often work in complex environments of multiple stresses,high temperature,long period and high radiation.Furthermore,engineering components often had all kinds of"notches"(such as shoulder steps,threads,keyways,etc.),which changed the stress distribution of the components under load.When the components were served,stress concentration at the notch would be easily loaded to the early initiation of cracks,and its service life was reduced finally.The performance index of smooth reflection couldnot direct the performance of actual components.In practical application,the data obtained by using smooth samples a small safety might lead to premature failure of components due to stress concentration at the notch and local actual stress exceeding the allowable stress of materials,thus caused aviation safety accidents.If a larger safety factor was adopted for safety,the mass of components would be too large,which contradicts the demand for weight reduction and wastes materials.Therefore,in order to ensure the safety and stability of aerospace vehicles and make full use of the properties of materials,it was very important to study the notch sensitivity and the influence of notch parameters on the deformation and fracture mechanism of high strength titanium alloy used for manufacturing its parts.Thus,in this paper,the fully lamellar microstructure of Ti-55531 alloy was obtained by solutionized at 860℃and then annealed at 610,640 and670℃for 3 h,respectively.The microstructural(including priorβgrain,αcolony andα

关 键 词：Ti-55531合金 缺口半径 片层组织 拉伸性能 

分 类 号：TG146.23[一般工业技术—材料科学与工程]