Strengthening of ordered Zr3Al by fast neutron irradiation

The room temperature tensile properties have been measured of Zr3Al irradiated by fast neutrons to a dose of 1.4 x 1024 n/m2. Yielding occurs discontinuously and is accompanied by the propagation of a Lueders band within which the strain, epsilon/sub L//sup phi/, is given by epsilon/sub L//sup phi/ = lambda/sup phi/d/sup -1/2/, where lambda/sup phi/ is an experimental parameter and d is the average grain size. The flow stress, sigma/sub f//sup phi/, including the yield strength, obeys an expression of the form sigma/sub f//sup phi/ = sigma0/sup phi/(epsilon) + k/sup phi/d/sup -1/2/ where sigma0/sup phi/(epsilon) and k/sup phi/ are experimental parameters; sigma0/sup phi/(epsilon) increases linearly with plastic strain, epsilon, while k/sup phi/ remains constant. The work-hardening rate is essentially independent of the grain size, as are the tensile strength and the ductility. Fracture occurs in a ductile mode. When compared with the behavior of unirradiated material, the results show that the irradiation increases the yield strength and decreases the work-hardening rate, but has little effect on the tensile strength, ductility and fracture