Orientation relationships in duplex Nb-Al-V alloys

A TEM study has been performed of the orientation relationships between lenticular A15 precipitates and the B2 matrix in Nb-10A1–20V and Nb-15A1–20V alloys in the homogenised and cold-rolled & annealed conditions. In most cases these precipitates exhibit the orientation relationship observed previously and the morphology suggests that this may arise because of lattice matching across the habit plane of the precipitates. For the cold-rolled and annealed sample of the Nb-15A1–20V alloy, however, an orientation which has not been reported previously was found.