The Influence of Substrate Treatment on Load Carrying Capacity of Ti6Al4VDuplex Coating

In this work, a duplex coating is performed by conducting microwave plasma nitriding on Ti6Al4 V, followed by the deposition of hardcoating (CrN) using an arc coating system. Plasma nitriding of Ti6Al4 V alloy using microwave plasma technique, created a thick (∼130 μm) modified layer (case depth) at processing temperature of 700 °C and 5 hour. The load carrying capacity of the duplex coating assessed using Rockwell-C test shows that the case depth increases with an increase in process temperature and time for nitriding. Consequently, it affects the formation of compound layer on the plasma nitrided specimen. Moreover, the formation of compound layer may lead to uneven distributions of the applied hardcoating (CrN) resulted in poor adhesion of hard coating - nitrided substrate.