Effect of Asynchronous Rolling Process on Microstructures and Properties of V-Ti-Ni Alloys for Hydrogen Separation

The experiments of asynchronous rolling were carried out to investigate the effect of different roll speed ratios on microstructures and mechanical properties of V-Ti-Ni (V60Ti20Ni20 and V70Ti15Ni15) alloys. The microstructure, rollability, hardness and texture of the rolled samples will be analyzed in this work. The results show that the ultimate reduction rates of the first pass rolling (r(up)) of V-Ti-Ni alloys increase firstly and then decrease with increase in the roll speed ratios (RSRs). After two alloys are rolled with 60% reduction, the hardness values of both alloys gradually increase with the RSR increases. At the RSR of 1:1.3, two alloys are elongated along the rolling direction under high shear strain, and the obvious fiber structures are formed. Besides, the difference in the degree of deformation between the upper part and lower part is significant. However, the rolled microstructures of both alloys show irregular deformation at the larger RSR, especially for V70Ti15Ni15 alloy. When the RSR is 1:1.2, the texture weakening effect of V60Ti20Ni20 alloy in the (2 0 0)(V) plane is most obvious. The analysis of these experimental results shows that asynchronous rolling can fully exert the plasticity of V-Ti-Ni alloys and control the microstructural anisotropic.

Automated summary

The effect of different roll speed ratios on microstructures and mechanical properties of V-Ti-Ni alloys was investigated through experiments of asynchronous rolling. The results show that the roll speed ratios have a significant influence on the reduction rates and hardness of the alloys, and can also lead to the formation of fiber structures. The rolled microstructures of the alloys exhibit irregular deformation.