Duplex nitriding treatment of a beta-metastable Ti94Mo6 alloy for biomedical applications

In the present work, nitridation process of a biocompatible beta-type Ti94Mo6 (at.%) alloy was carried out to optimize the microhardness and brittleness surface characteristics. We propose a duplex treatment consisting of a superficial gas nitriding at high temperature followed by an annealing treatment. By this treatment, the superficial TiN layer is transformed into a nitrogen rich α-Ti layer with a superior adherence on the substrate. The coated Ti94Mo6 alloy combines the profitable bulk properties of the beta-type microstructure and a superior superficial microhardness reducing the wear debris in service for a use as prosthetic device.