Enhanced strength and corrosion resistance in as-cast TA10 alloys via interstitial carbon solute

The addition of interstitial elements generally has a significant impact on the macroscopic performances of structural alloys. Here, we report a systematic study on the microstructure, corrosion behaviors and mechanical properties of a series of as-cast Ti-0.3Mo-0.8Ni-xC (x = 0.09, 0.12 and 0.15 wt.%) alloys. A typical basket-weave microstructure appears in all specimens, characterized by the lamellar alpha-phase and intergranular retained beta-phase without TiC precipitates within the prior beta grain boundary. Based on the electrochemical and immersion tests, doping with C element can significantly improve the corrosion resistance of TA10 alloys; with increasing the carbon content, the passivation current density decreases from 5.750 to 4.938 mu A center dot cm(-2), the breakdown potential increases from -1.115 to -1.223 V versus SCE, the corrosion rate reduces from 15 mm/a to 7.5 mm/a. Moreover, the mechanical properties of TA10 alloys, such as the strength and hardness, can also be enhanced via C alloying. Our results indicate that the addition of interstitial elements should be a potential effective mean to accommodate the comprehensive performances of TA10 alloys.

Automated summary

The addition of carbon significantly improves the corrosion resistance and mechanical properties of TA10 alloys, with increasing carbon content leading to optimization of corrosion rate and breakdown potential.