The microstructures and mechanical properties of martensite Ti and TiN phases in a Ti6Al4V laser-assisted nitriding layer

A fiber laser assisted the preparation of a nitride layer on the Ti6Al4V surface in a pure nitrogen atmosphere. Through SEM, XRD, and XPS analyses, the nitride layer is found to be mainly composed of dendritic TiN phase and an interdendritic α′-Ti phase. Not only the true crystal structure of the two main phases (TiN and α′-Ti) were directly characterized using TEM, but also the mechanical properties were tested by micro-indentation and...