Abstract：Surface nitridation of titanium was induced by pulsed laser irradiation in nitrogen atmosphere.The nitridation layers were characterized by scanning electron microscope(SEM),X-ray diffraction(XRD)and Raman spectroscopy.XRD results showed that the main phases of the nitridation layers were α-Ti and δ-TiN,with a small amount of α-Ti(N).With the increase of laser average power,δ-TiN and α-Ti(N)content in the nitridation layers increased.Correspondingly,the nitrogen content also increased.The hardness and Young’s modulus of the nitridation layers were measured by nano-indentation with a load of 2mN and found to be 11.5~15GPa and 200~250GPa,which were much higher than that of titanium.
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