退火后冷却方式对BT25钛合金组织和性能影响

Effect of cooling methods after annealing on microstructure and properties of BT25 titanium alloy

本文用光学显微镜(OM)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)研究了退火后冷却方式对BT25钛合金的显微组织和室温力学性能影响.结果表明:一次退火后水冷,BT25钛合金的基体可以获得相较于空冷而言更为细小的β转变组织,但对初生α相的影响不大;同时合金的拉伸强度因片状α相的细小而更高,且合金的断后伸长率下降.因此,要使BT25合金获得更高的强度,一次退火后应进行水冷.

The effect of cooling method after annealing on the microstructure and mechanical properties of BT25 titanium alloy at room temperature was in vestigated by using optical microscope (OM), scan electron microscope (SEM) and transmission electron microscope (TEM). The results show that as for the water cooling after first annealing, the matrix of BT25 titanium alloy can obtain finer B transformation structure than that of air cooling, with little effect on the primary a phase. Meanwhile, the tensile strength of the alloy is greater due to the fineness of lamellar a phase, while the elongation after fracture of the alloy decreases. Therefore, in order to obtain higher strength of BT25 alloy, water cooling should be carried out after first annealing.