A new approach to synthesis Ti2AlC MAX phase using PVD coating and post-laser treatment

The Ti2AlC MAX phase was synthesized on the Ti-6Al-4V alloy substrate using a novel technique. In contrary to the most techniques used for synthesizing the MAX phases in which the metal powders were the main raw material, the metal powder wasn't used in this procedure. The Ti-6Al-4V plates were carbon coated by physical vapor deposition (PVD), and then the Nd: YAG and diode lasers were irradiated on the coated samples. The laser process was performed at different variables including the power, scan speed, and focal position of the laser. The laser-treated samples were investigated by optical microscopy, X-Ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM) equipped with energy disperse spectroscopy (EDS). In addition to the other phases such as titanium carbide (TiC) and titanium nitride (TiN), the Ti2AlC MAX phase was also detected by the XRD analysis. The hardness of the coated irradiated samples was nearly 2.5 to 4.5 times higher than the substrate. The wear and friction performances of the samples was evaluated using a reciprocal wear device in which the AISI 52100 steel with the hardness of 63 HRC was used as the counterpart. The wear rate of the laser-treated sample decreased about 81% with respect to the Ti-6Al-4V substrate. The average friction coefficient reduced nearly 66% after the laser treating of the Ti-6Al-4V sample. The SEM images of the worn surfaces and debris were used to deduce the wear mechanisms. The abrasive wear was the dominant wear mechanism.