Influence of Al addition on electrical resistivity and phase constitution in quenched Ti-20 mass%V alloy.

Abstract

Electrical resistivity anomalies in type Ti alloys including negative temperature dependence were previously interpreted by fully reversible formation and disappearance of athermal phase with cooling and heating. In the present work, influence of Al addition up to 10 mass%on some properties of Ti-20%V alloy in as quenched state from region were investigated. Resistivity increases with concentration of solute Al. Addition of 3%Al changes the temperatureresistivity curve of Ti-20%V alloy, which had a resistivity maximum between 77K and room temperature, to the curve having negative temperature coefficient in whole of the above temperature range. In alloys below 5%Al, hardness decreases slightly with Al addition, namely no solid solution hardening by Al can be observed. However, the hardening appears above 8%Al clearly. These results suggest that the starting, perhaps also finishing, temperature of athermal phase formation is lowered and that the amount of athermal phase at room temperature is decreased by the Al addition. This interpretation is qualitatively confirmed by electron diffraction.