Analysis of pseudoelastic behavior of Gum Metal by Nanoindentation

Generally, elastic modulus of metallic materials has proportional relations with their mechanical strength. However, a beta titanium alloy, Gum Metal, was developed to have both low elastic modulus and high strength, where severe cold working is required for such mechanical properties. In addition, Gum Metal has multifunctional characteristics, which can be attributed to its unique deformation mechanism. Many studies have been performed to understand this deformation mechanism, and nanoindentation has been used to study a local mechanical behavior of Gum Metal, and several new results have been found in load-displacement curves during nanoindentation. One of them is strong strain-rate dependence of mechanical behavior, which is considered to be related to pseudoelasticity. In this study, we performed nanoindentation using Gum Metal and similar beta titanium alloy, βIII, and compared mechanical behavior during nanoindentation to study the pseudoelastic deformation of Gum Metal.