Superplastic behavior of 5083+0.12Zr alloy was investigated in the temperature range from 783 to 843K and in the strain rate range from 8×10-5 to 3×10-3S-1 at constant strain-rate tensile test. Maximum elongation of 580% was obtained at 823K and at strain rate of 1×10-4S-1, where m value retains its initial value of 0.5 up to a large strain of 1.3 and where minimum cavitation occurs. The large elongation is due to stable deformation caused by retaining the initial m value up to large strain. The alloy showed strain hardening which is induced by dynamic grain growth. Dynamic grain growth rate increased with decreasing strain rate. Decreasing of m value with true strain may be attributed to decreasing grain boundary caused by cavitation and grain growth.
