氢对Ti-6Al-4V合金微观组织的影响

Effect of Hydrogen on Microstructure of Ti-6Al-4V Alloys

摘要:

采用累计流量法对供应态Ti-6Al-4V合金进行了固态置氢，运用OM、XRD、TEM分析等方法研究了Ti-6Al-4V合金固态置氢后的微观组织状态及演变过程。结果表明：供应态Ti-6Al-4V合金的置氢量低于0.30%(质量分数，下同)时，置氢使得Ti-6Al-4V合金中的α相减少、β相增加；置氢量达到0.30%时，置氢Ti-6Al-4V合金中有δ氢化物（TiH2相）形成；β-Ti（H）共析转变生成α-Ti和δ氢化物时主要以切变方式进行；置氢Ti-6Al-4V合金的相变温度最多下降了180 °C，与Ti-6Al-4V合金在置氢过程中的相体积比变化和共析转变有密切关系。

Abstract:

Hydrogenation of Ti-6Al-4V titanium alloys was carried out in a special furnace through the accumulated flux method, and OM, XRD and TEM techniques were used to investigate the microstructure evolution of the hydrogenated Ti-6Al-4V titanium alloy. The hydrogenation of the Ti-6Al-4V titanium alloy with the hydrogen content of 0.30 wt% makes the α phase fraction decrease compared with that of the as-received Ti-6Al-4V titanium alloy, but it makes the β phase fraction increase. The δ hydride (TiH2 phase) occurs in the hydrogenated Ti-6Al-4V titanium alloy when the hydrogen content is more than 0.3 wt%. The shear deformation is main pattern in the transformation processes from β-Ti(H) phase to α-Ti phase and δ hydride (TiH2 phase). The phase transformation temperature of the hydrogenated Ti-6Al-4V titanium alloy decreases by 180 °C compared with that of the as-received Ti-6Al-4V titanium alloy, and it is related to the phase fraction and phase transformation.