Fatigue behavior of copper zinc aluminum shape memory alloys

Abstract

Copper Zinc Aluminum (CuZnAl) shape memory alloys (SMA) are receiving wide attention in recent years ue to applications in smart (adaptive) structures. A stress-induced phase transition occurs in SMAs that causes inelastic deformation and gives rise to an energy-absorbing capacity. Due to this inelastic deformation associated with SMA, CuZnAl shape memory alloys should be capable of having high fatigue lives. The energy-absorbing capacity and possible high fatigue lives makes CuZnAl promising material in the elimination of vibration induced fatigue failures in structures. In order to use CuZnAl in structural applications, a thorough study of its mechanical properties is required. In this thesis, the mechanical and fatigue properties of both austenitic $(M\sb{S}={-}7.3\sp\circ C)$ and martensitic $(M\sb{S}=42\sp\circ C)$ CuZnAl have been studied at room temperature through a mechanical testing program. The energy-absorbing capacity of superelastic, austenitic CuZnAl is also measured. Tensile, strain cycling, and low- and high-cycle fatigue tests were conducted at room temperature on austenitic and martensitic CuZnAl alloys. (Abstract shortened by UMI.)