Deformation and improvement of ductility of the intermetallic compounds Al₃ V and Al₃(V, Ti)

Abstract

Polycrystalline specimens of the intermetallic compounds Al₃V and Al₃(V, Ti) containing 1 - 25 at.% Ti with the D0₂₂ structure have been deformed under compression temperatures between 20 and 900°C. Al₃V shows only a small fracture strain at low temperatures. The deformation is mainly controlled by the motion of 〈110〉-type dislocations without twinning. The activation of 〈110〉 and 〈010〉 slip in addition to 〈110〉 slip contributes to the ductility improvement at high temperatures.

Ductility of Al₃V has been found to be induced by the replacement of vanadium by titanium. For example, Al₃(V_0.95Ti_0.05) shows 7% compressive fracture strain at room temperature. In Al₃(V_0.95Ti_0.05) deformed at room temperature, not only dislocations but also numerous deformation twins and stacking faults are observed. Therefore, the improvement of ductility of Al₃V by the partial replacement of vanadium by titanium arises from a substantial increase in the activity of the ordered twinning which is not operative in the binary compound Al₃V.