Arc deposition of wear resistant layer TiN on Ti6Al4V using simultaneous feeding of nitrogen and wire

Abstract

As an admirable surface improvement method, arc surface cladding has been widely used in various fields. The surface properties of titanium alloy were improved by gas tungsten arc cladding. In the process of arc claddings, a certain amount of nitrogen was added in the shielding gas to form the hard phase of TiN in the cladding layer. Titanium alloy surface was cladded with the same process parameters and different nitrogen flow rate. The effects of nitrogen flow rate on the microstructure and mechanical performance of the cladding layer were studied through an optical microscope, scanning electron microscope (SEM), X-ray diffraction (XRD), Vickers hardness and friction wear testing machine. The results show that the increase of the nitrogen flow rate not only changes the shape of the arc but also forms a large number of TiN hard phases in the cladding layer. With the increase of the nitrogen flow rate, the number of TiN hard phases in the cladding layer increases gradually, which improves the mechanical property of the cladding layer. The Vickers hardness of the cladding layer is much larger than 600 HV and the friction coefficient is 0.419 when the nitrogen rate is 2 L/min.