Effects of temperature and loading rate on the deformation characteristics of superelastic TiNi shape memory alloys under localized compressive loads

TiNi shape memory alloy (SMA) has been widely used in various applications from biomedical and micro-electro-mechanical systems (MEMS) to aerospace applications. The great interest in TiNi shape memory alloy is due to its unique shape memory and superelasticity effects, as well as, its superior wear and dent resistance. Shape memory (SM) and superelastic (SE) effects are due to reversible martensitic transformation. Although the behavior of TiNi shape memory alloy is well established under tensile conditions, its behavior under compressive conditions is not well understood. In this study, indentation tests are performed, at different temperatures, loads and loading rates on superelastic TiNi alloy. Deformation characteristics of superelastic TiNi under indentation are compared to AISI 304 steel. An understanding of the impact of loading rate and temperature on the deformation behavior of TiNi SMAs under localized compressive loads is proposed.

► Deformation of suerelastic TiNi under a spherical indenter.
► Impact of loading rate dent resistance of TiNi.
► High temperature and high loading rate diminishes superelasticity.