Interactions of titanium carbides, nitrides, and oxides with concentrated mineral acids

The results on the interaction of TiCx (x = 0.97-0.65), TiNx (x = 0.95-0.61 ), and TiOx (x = 1.20-0.82) with concentrated hydrochloric, sulfuric, and n itric acids are reported. The discussion is in terms of the electronic stru cture of metal-like refractory interstitial phases (RIPs) including the det ails of redox processes accompanying dissolution. The chemical stability of TiCx, TiNx, and TiOx is controlled by the metallicity of Ti-Ti bonds. The factors influencing the stability are the nonmetal of the RIP, the passivat ing capacity of the nascent reaction products, and gas evolution (or its ab sence) upon dissolution.