Effect of carbon on microstructure and mechanical properties of a eutectoid β titanium alloy

The influence of carbon addition on the aging response of quenched Ti-13wt.%Cr has been investigated using hardness tests, tensile tests, optical microscopy, scanning electron microscopy, and transmission electron microscopy. The addition of carbon improves the homogeneity of alpha precipitation, reduces the growth rate of alpha, and greatly reduces grain boundary alpha precipitation. The carbon addition accelerates the rate at which hardening occurs during aging, increases the peak hardness of aged samples, and also increases the room temperature tensile strength and ductility of aged samples. The factors giving rise to the improvements in properties will be discussed in terms of the microstructural observations.