Effect of in-situ formed TiC particles on corrosion resistance of Fe–TiC alloys in Al melt

In-situ formed TiC particles were introduced into α-Fe matrix as corrosion-resistant phases to enhance corrosion resistance against aluminum melt of the alloy. The effects of TiC content on the microstructure and corrosion behavior of Fe–TiC alloys were examined both experimentally and theoretically. The results indicate that eutectic Fe–6TiC alloy offers superior corrosion resistance to liquid aluminum, which is 7.5 times greater than that of H13 die steel. The long rod-shaped and granular eutectic TiC particles provide superior resistance to aluminum melt diffusion compared to blocky primary TiC. Moreover, these eutectic TiC particles improve the bonding strength of the intermetallic compound layer, inhibiting cracking, peeling, and dissolution of the corrosion layer. A novel theoretical numerical model is established to quantitatively account for the corrosion behavior of the ferrous alloys in aluminum melt, and the diffusion inhibition factor λ and dissolution inhibition factor ε are introduced in this work to quantitatively estimate the corrosion performance. Theoretical analysis demonstrates that Fe–6TiC eutectic alloy containing numerous long rod-shaped and granular eutectic TiC exhibits the best corrosion resistance.