Equilibria in the Zr-Hf-Sn system in the region up to 37.5Â at.% Sn

Phase equilibria in the zirconium-hafnium-tin system between the Mn5Si3-type intermetallic and the (Zr,Hf) rich solid solution were determined studying three alloys of selected compositions in the region up to 37.5 at.% Sn. Phase characterizations were made on heat-treated specimens at 900 and 1100 °C by metallographic observations, X-ray diffraction diagrams and electron microprobe analysis. Lattice parameters of the phases in equilibrium were calculated. General sketches of equilibria and phase boundaries at the mentioned temperatures were outlined from the obtained results.