Hydrogen, as a temporary element in titanium alloys, is very good in controlling microstructure. The microstructure and phase transformation of Ti6Al4V alloy are affected by the amount of TiH2 added into the melt of T...Hydrogen, as a temporary element in titanium alloys, is very good in controlling microstructure. The microstructure and phase transformation of Ti6Al4V alloy are affected by the amount of TiH2 added into the melt of Ti6Al4V alloy during the induction skull melting （ISM） process. This process ,called melt hydrogenation, was studied in this paper through the use of optical microscopy, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results are as follows： after melt hydrogenation, both the solidification macrostructure and microstmcture of Ti6Al4Valloy are refined; the a phase precipitates in a lamellar form with the residual β phase from the grain boundaries; δ-hydrides precipitate during the solidification process as a result of the existence of hydrogen. The phase with an F. C. C. structure can be.observed by TEM in the α phase laminae of specimens with 1.25% TiH2. In addition, the dependence of the microhardness of specimens on the weight percentage of TiH2 added to the melt during the ISM process was also studied.展开更多
文摘Hydrogen, as a temporary element in titanium alloys, is very good in controlling microstructure. The microstructure and phase transformation of Ti6Al4V alloy are affected by the amount of TiH2 added into the melt of Ti6Al4V alloy during the induction skull melting （ISM） process. This process ,called melt hydrogenation, was studied in this paper through the use of optical microscopy, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results are as follows： after melt hydrogenation, both the solidification macrostructure and microstmcture of Ti6Al4Valloy are refined; the a phase precipitates in a lamellar form with the residual β phase from the grain boundaries; δ-hydrides precipitate during the solidification process as a result of the existence of hydrogen. The phase with an F. C. C. structure can be.observed by TEM in the α phase laminae of specimens with 1.25% TiH2. In addition, the dependence of the microhardness of specimens on the weight percentage of TiH2 added to the melt during the ISM process was also studied.
