Ti6Al4V合金热浸镀铝的空蚀行为研究

Study on Cavitation Erosion Behavior of Hot-dip Aluminizing on Ti6Al4V Alloy

采用热浸镀法在Ti6Al4V合金表面制备Ti Al3涂层,并在550℃真空保温5 h。对热浸镀后材料与Ti6Al4V合金进行了空蚀试验对比。通过X射线衍射仪、扫描电镜及显微硬度测量等手段研究了涂层的组织形态和耐空蚀性能。结果表明:热浸镀铝比Ti6Al4V合金空蚀累积质量损失低,具有更好的抗空蚀性能,这与Ti6Al4V合金表面形成的Al3Ti的强化作用有关。热浸镀铝和Ti6Al4V合金空蚀20 h后横截面显微硬度都降低,发生了加工软化现象,使得材料表面逐渐脱落。

TiAl3 intermetallic matrix composite coating was fabricated on Ti6Al4V alloy by Hot-dip aluminizing, and vacuum insulation at 550℃ for 5 h. Then, it was compared with Ti6Al4V alloy on cavitation erosion test. The microstructure and the cavitation erosion resistance of the coating were analyzed by XRD, SEM. The results indicate that the cavitation erosion cumulative mass loss of hot-dip aluminizing is lower than that of Ti6Al4V alloy, and it shows better resistance to cavitation erosion due to that the reinforcement of TiAl3. The cross-section microhardness of hot-dip aluminizing and Ti6Al4V alloy are reduced after cavitation erosion for 20 h, the processing softening phenomenon happenes, which makes the material surface gradually fall off.