强韧化热处理对TA15钛合金组织和性能的影响  

Effect of strengthening and toughening heat treatment on microstructure and mechanical properties of TA15 titanium alloy

作　　者：卢凯凯[1] 周立鹏[1] 李敏娜 马保飞[1] 肖松涛[1] LU Kai⁃kai;ZHOU Li⁃peng;LI Min⁃na;MA Bao⁃fei;XIAO Song⁃tao(Northwest Institute for Nonferrous Metal Research,Xi’an 710016,China)

机构地区：[1]西北有色金属研究院

出　　处：《材料热处理学报》2020年第1期44-49,共6页Transactions of Materials and Heat Treatment

摘　　要：采用光学显微镜,扫描电镜和电子拉伸机等研究了TA15合金经两阶段强韧化退火热处理后的显微组织和性能。结果表明:采取两阶段的热处理工艺后,TA15合金的组织由约20%的初生等轴α,55%的片状α和β转变基体的组织组成;合金具有良好的塑性及较好的室温和高温强度,在975℃×1 h,WQ+850℃×2 h,AC的制度下,TA15合金的室温抗拉强度为1005 MPa,屈服强度为914 MPa,伸长率、冲击韧性分别为13%和72.2 J/cm^2。合金的冲击韧性I与次生片层α厚度t具有较好的线性关系I=26.504t+44.915,冲击断口形貌可以观察到大量的韧窝,表明合金的断裂机制以韧性断裂为主。随着第二重退火温度的升高,次生片层α厚度增加,韧窝逐渐变大,韧性增加。Microstructure and properties of TA15 alloy after two-stage strengthening and toughening annealing treatment were studied by means of optical microscope, scanning electron microscopy and tensile test. The results show that the microstructure of TA15 alloy is composed of about 20% primary equiaxed α, 55% lamellar α plates and β transformation matrix after two-stage heat treatment. The alloy has good plasticity and good room temperature and high temperature strength. After solid solution treatment at 975 ℃ for 1 h by water quenching and then annealing at 850 ℃ for 2 h by air cooling, the room temperature tensile strength and yield strength of the TA15 alloy are 1005 MPa and 914 MPa, respectively, and the elongation and the impact toughness are 13% and 72.2 J/cm^2, respectively. The impact toughness I of the alloy has a good linear relationship with the secondary lamellar α thickness t, I=26.504t+ 44.915. A large number of dimples can be observed in the impact fracture morphology of the alloy, indicating that the fracture mechanism of the alloy is mainly ductile fracture. With the increase of the second annealing temperature, the thickness of the secondary lamellar α plate increases, the dimple increases gradually and the toughness of the alloy increases.

关 键 词：TA15钛合金 力学性能 热处理 冲击韧性 

分 类 号：TG146.2[一般工业技术—材料科学与工程]