THE TENSILE PROPERTIES OF A TEXTURED TI65AL25NB10 ALLOY

The alpha-2 alloy Ti65Al25Nb10 can form a sharp (001) basal plane texture following a two-step hot rolling procedure and subsequently heat treatment. A tensile test has been conducted on this textured alloy. The elongation in the rolling direction and the reduction in the width direction are both found to increase significantly compared with the Ti3Al alloys, but the reduction in thickness is similar to that in the Ti3Al alloys. The yield stress of the textured alloy is below that of the Ti3Al alloys. It is proposed that the type < a > and type < c + a > dislocation slippings are related to the reductions in width and thickness respectively. It is suggested that the improvement in elongation in this textured alloy results from the lower average orientation factor MBAR and from the smaller grain boundary angles present in the textured alloy. Both factors contribute a lower blocking energy of the grain boundaries for dislocation slipping.