The Effect of Aging on the Microstructure of Alloys (ТiСr1.8)100–xVx after Electrolytic Hydrogen Charging

Abstract

The microstructure transformation of ternary Ti-Cr-V alloys after introduction of hydrogen has been analyzed for a long time. Assessment of the impact of vanadium concentration and ratio of Ti and V concentrations on composition stability has been carried out. Investigated alloys system corresponds to relation (TiCr1.8)100–xVx. The atomic ratio Ti/Cr is constant. Vanadium content changes with the step 20 at.%. The hydrogen charging has been carried out in a thermostatic three-electrode electrochemical cell using 1M KOH electrolyte (ic = 10–30 mA/cm2) at 293 K for three hours. It was established that the hydrogen introduction leads to surface migration of alloy components. Their distribution oscillates as time passed. This is due to the fact that hydrogen interacts differently with titanium and vanadium. The electrolytic hydrogen introduction initiates deformation of the crystal lattice and self-diffusion of alloy atoms. The statistically nonuniform distribution of electrolytic hydrogen increases the intensity of the process. The relaxation of internal stresses leads to further redistribution of components. The observed changes depend on the vanadium content in the alloys and have a different character inside the grain and near grain boundaries. A significant change has been established for (TiCr1.8)60V40.