Corrosion and electrochemical behavior of crystalline and amorphous titanium-cobalt alloys with admixtures of boron, silicon and phosphorus

The authors attempt to elucidate the influence of boron, silicon, and phosphorus on the corrosion and electrochemical behavior of titanium-cobalt alloys with nearly eutectic composition. Of the investigated additives, only phosphorus is an effective alloying element for alloys of the titaniumcobalt system. Addition of 5 at. % of P causes self-passivation of the alloys, regardless of their structure in 5 N H/sub 2/SO/sub 4/ solution, with a corresponding improvement in corrosion resistance. Amorphization of the phosphorus-containing alloy promotes the formation of a homogeneous passivating film, consisting mainly of titanium dioxide, which has good, stable protective properties.