Compressive deformation and electrochemical analysis of Ti4AlxCo alloy

Abstract

Ti4AlxCo (wt%) (x = 0%, 2%, 4%, and 6%) were synthesized via powder metallurgy route. Effect of Co content on the phase formation, microstructural transformation, compressive deformation and electrochemical behaviour of the alloy were investigated. Phase formation and microstructural analysis were done with the help of XRD and FESEM respectively. Compression test was performed to investigate the yield strength and modulus of elasticity of the alloy. Synthesized alloys were analyzed by electrochemical method to probe their resistance to corrosion in the Hank’s solution. XRD test confirms the formation of Ti2Co phase in the alloy which volume fraction increases with the increment of Co content. Leafy columnar structure of Ti2Co phase was clearly observed in the microstructure of the alloy containing Co. Compressive yield strength (σy) and elastic modulus (E) of Ti4Al sample are about 45% and 25% lower than the sample made of commercially pure (CP) Ti. Addition of Co content improves σy as well as E. However, alloys containing more than 2 wt% of Co have higher elastic modulus than Ti6Al4V which may be a concern to use them as a bone scaffold. In Tafel plot, corrosion current density (Icorr) shifts towards the higher value with the increment of Co content causing the reduction of corrosion resistance.