Synthesis of Ti(C, N) ceramic layer on surface of Ti–6Al–4V alloy via pack nitro-carburizing route

In the present study Ti(C, N) ceramic layer was synthesized on the surface of Ti–6Al–4V alloy by pack nitro-carburizing method to improve surface properties of this alloy. Rectangular blocks were placed in a carbon contained graphite cup and heat treated in a nitrogen atmosphere at different temperatures and soaking times. Phase analysis results indicated that higher treatment temperatures led to increase carbon concentration in Ti(C, N) phase. Almost uniform layer with very high hardness compared to the base material was synthesized and the thickness of the layer increased with increasing treatment time and temperature. Also, corrosion resistance of the alloy was improved dramatically after pack nitro-carburizing process. In some samples, separation of a layer from base material was observed and a suggested mechanism for this phenomenon was declared.