On the Low-Temperature Complex Surface Modification of Titanium Alloys

The results of a study of the change in the microhardness and chemical composition in the surface layers of two-phase titanium alloys after complex modification in high-density plasma are presented. Complex surface modification in a single vacuum cycle includes the following operations: ion cleaning of the surface and heating of the sample in argon plasma, deposition of nitride-forming elements onto the surface, and low-temperature (no more than 550°C) nitriding in high-density plasma. The phase and elemental composition, microhardness of the surface layer, and roughness are investigated to determine the effect of the modes of complex modification on the characteristics of the surface layers. Complex surface modification results in a significant, up to twofold, increase in the microhardness of the modified layer. The change in the microhardness is associated with the formation of an interstitial solid solution as well as titanium nitrides containing dispersed particles of nitrides of titanium and aluminum intermetallic compounds.