Deformation behavior of Zr(3)AI-Nb alloys I: Room-temperature and high-temperature deformation study

Abstract

The deformation behavior of the Zr3Al-Nb alloys was studied by measuring hardness at different temperatures, by hot rolling, and by hot pressing. Using the hardness data, elasticity and plasticity parameters were estimated and were used to determine the suitable temperature range of deformation for these alloys. Hot rolling and hot pressing were applied to determine the optimum temperatures and annealing time for carrying out deformation successfully in these alloys. Microstructural investigation of the hot-deformed samples revealed that the matrix beta phase has undergone substantial deformation and the second intermetallic phase, Zr-2(Al,Nb), underwent dissolution and re-precipitation. The hardness of the fully annealed Zr3Al-Nb alloys showed two types of temperature dependence. Transition temperatures for the change in behavior, intrinsic hardness, and softening coefficient were determined. The hardness of the fully annealed alloys rolled to different extent at various temperatures and subsequently heat treated was used to study the recovery process. ne microstructural study of room-temperature deformed binary Zr3Al alloy showed the splitting of the superlattice dislocations into partials containing superlattice intrinsic stacking faults.