Hot hardness and indentation creep behaviour of Zr(3)A1-Nb alloys

Zr3Al based intermetallics have been considered as candidate materials for structural components in nuclear reactors. Ternary addition of niobium has been found to influence the microstructure and mechanical properties of the se materials. The present paper reports mechanical properties including cre ep rates of binary Zr3Al and ternary Zr3Al-10Nb alloys measured from microi ndentation experiments carried out in the temperature range of 300 K to 130 0 K. Niobium addition was found to increase the high temperature strength u p to about 800 K without sacrificing ductility. However. the onset temperat ure for softening was lower ill the case of the ternary alloy. Creep rates at different temperatures and activation energies of high temperature creep have been determined for both binary Zr3Al and ternary Zr3Al -10Nb alloys. Zr3Al based alloys have shown a lower steady state creep rate than many of the structural intermetallics such as Ni3Al. Fe3Al and FeAl.