Investigation On The Surface Nanocrystallization Of Ti6Al4V And Its Plasma Source Ion Implantation

It is known that most engineering materials failures occur on the surface on most occasions. The working duration of materials was greatly extended due to lots of technics that applied to enhance the surface mechanical properties. Surface nanocrystallization is a way that can achieve surface modification by generating a nanostructured surface layer. Usually, the surface layer can be formed by physical or chemical ways. The application of surface nanocrystallization is considered to be a prospective way that can effectively develop materials' performance.In this paper, by means of circulation rolling plastic deformation (CRPD), a nanostructured surface layer was formed on the Titanium alloy (TC4, Ti6Al4V). Microstructure features were systematically characterized by using light optical microscopy, X-Ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) observations. And Vickers microhardness was measured. The observations and results indicated that the nanostructured layers were induced on surface of TC4 alloy. The mean grain size was about 15nm in the layer, and the depth of layer was about 400μm. With the extension of CRPD duration, the deformation layer would be deeper and the Vickers hardness of surface would be improved. The maximal microhardness of deformation layer was about 525HV0.1. Simultaneously, hardness gradually fell from the treated top surface to the strain-free matrix. The annealing experiment indicated that grain size in...