Microstructure and Mechanical Properties of Coarse and Ultrafine Grain Titanium with Different Iron Contents

Abstract

Severe plastic deformation (SPD) processed ultrafine grain (UFG) Ti has been receiving much attention by biomedical industry due to its excellent mechanical and physical properties. In addition, the biomedical industry is paying special attention to the commercially pure titanium (CP-Ti) with low iron. However, there is a scarcity of readily accessible public literature to explain the reasons for choosing CP-Ti with low iron for biomedical applications. Hence, in current study detailed microstructure and mechanical property characterization of coarse grain (CG) Ti and UFG MITHRALMAX® CP-Ti (ASTM Grade 4) with various iron contents, plus other compositional variations, has been carried out. Ti with low iron content showed wider spread in grain size in both CG and UFG conditions. However, the Ti with medium and high iron contents showed more uniform grain structure in both CG and UFG conditions. Ti with medium iron content showed enhanced tensile properties compared to Ti with low and high iron contents in both CG and UFG conditions. The fatigue resistance is also higher in Ti with medium iron content in both CG and UFG conditions.