TC11钛合金高温持久异常断裂分析  

High Temperature Endurance Abnormal Fracture Analysis of TC11 Titanium Alloy

作　　者：邵博 张利军 吴天栋 田军强 马坤 Shao Bo;Zhang Lijun;Wu Tiandong;Tian Junqiang;Ma Kun(Xi’an Chaojing Technology Co.,Ltd.,Xi’an 710200,China;Shaanxi Key Laboratory of Advanced Metal Structural Materials Precision Thermoforming,Xi’an 710200,China)

机构地区：[1]西安超晶科技股份有限公司,陕西西安710200 [2]陕西省先进金属结构材料精确热成形重点实验室,陕西西安710200

出　　处：《钛工业进展》2023年第3期28-32,共5页Titanium Industry Progress

基　　金：上海航天科技创新基金项目(SAST 2017-055)。

摘　　要：为分析TC11钛合金高温持久试样异常断裂原因,通过光学显微镜(OM)、扫描电子显微镜(SEM)观察分析高温持久异常断裂试样的断口及表面微观形貌,并用能谱仪进行微区成分分析。异常断裂试样表面发生明显氧化和多处开裂,试样断口边部存在多处深褐色氧化凹坑,断口外圆周凹坑处多发生沿晶断裂,心部为韧性断裂。试样表面裂纹区域含有Cl、Mg、Na等元素,是导致试样异常断裂的直接原因。Mg、Na、Cl等元素是由捆绑热电偶的石棉绳引入,在高温环境下试样表面发生热盐应力点腐蚀,随着高温持久试验应力的持续加载试样发生形变,点腐蚀凹坑处产生裂纹并迅速延伸导致试样异常断裂。采用镍铬丝捆绑热电偶时试样表面未发生热盐应力腐蚀,其对TC11钛合金持久性能的影响很小。In order to analyze the cause of abnormal fracture of high temperature endurance TC11 titanium alloy specimens,the fracture and surface morphology of the specimens were observed and analyzed by optical microscope(OM)and scanning electron microscope(SEM),and the micro-area composition was analyzed by energy spectrometer.Obvious oxidation and multiple cracks occur on the surface of the abnormal fracture specimen,there are many dark brown oxidation pits on the edge of the fracture specimen,intergranular fractures occur mostly in the pits on the outer circumference of the fracture,and ductile fractures occur in the core.Cl,Mg,Na and other elements are found in the crack region of the specimen surface,which is the direct cause of abnormal fracture of the specimen.Mg,Na,Cl and other elements are introduced by the asbestos rope binding the thermocouple,and hot salt stress point corrosion occurs on the surface of the specimen under high temperature environment.With the continuous loading of the test stress at high temperature,the specimen deformation occurs,and cracks occur at the point corrosion pit and rapidly extend,leading to abnormal fracture of the specimen.There is no thermal salt stress corrosion on the surface of the specimen when the chromite wire is used to bundle the thermocouple,which has little effect on the durability of TC11 titanium alloy.

关 键 词：TC11钛合金 高温持久性能 失效分析 热盐应力腐蚀 

分 类 号：TG146.23[一般工业技术—材料科学与工程]