退火温度及保温时间对激光沉积制造TA15钛合金微观组织和显微硬度的影响

Effect of annealing temperature and soaking time on microstructures and microhardness of laser deposition manufacturing TA15 titanium alloy

以TA15钛合金球状粉末为原料,TA15钛合金锻件为基材,利用激光沉积制造技术成形TA15钛合金厚壁件。利用光学显微镜(OM)、扫描电子显微镜(SEM)以及显微硬度仪等方法研究退火温度及保温时间对激光沉积TA15钛合金显微组织和显微硬度的影响。结果表明:退火温度相同时,随着退火温度的升高,保温时间越长,α相就越能充分生长。退火保温时间越长,α相宽度越大。退火温度及退火保温时间影响α相体积百分比含量,α相百分比含量随退火时间延长而增多。α相在不同保温时间下存在不同的生长方向。显微硬度值与α相体积百分比含量具有一定关系,α相体积百分比含量增多时,显微硬度值变大。

TA15 titanium alloy bulk specimens were prepared with spherical powder and forging substrates in laser deposition manufacturing. The effects of annealing temperature and soaking time on microstructure characteristics and microhardness were investigated by optical microscope （OM）, scanning electron microscopy （SEM） and microhardness instrument. The experimental results show that alpha phase grows fully resulting from annealing temperature increase and longer soaking time at same annealing temperature. The width of the alpha phase becomes larger with the extension of the soaking time. The percentage content of alpha phase grows with annealing time extension. Alpha phase exists different growth direction in different annealing soaking time. There are some certain relationship between microhardness and volume content of alpha phase, microhardness is enhanced with the increases of percentage content of alpha phase.