Modification of Microstructure and Surface Properties of Ti-6Al-4V Alloy by MoSi2 Particles Using Micro-Arc Oxidation Process

As an effective surface modification technique, micro-arc oxidation (MAO) is now widely used to improve the hardness and wear resistance of Ti and its alloys by low-cost and thick ceramic coatings.In this study, molybdenum disilicide (MoSi 2 ) -modified ceramic coatings were deposited on Ti-6Al-4V alloy (340 HV) by MAO using an aqueous solution of Na 2 SiO 3 , (NaPO 3 ) 6 and NaOH and MoSi 2 particles.MoSi 2 particles (3, 5, and 7 g/l) from wastes of furnaces electrodes were introduced into the electrolyte to improve the microstructure and surface properties of Ti-6Al-4V alloys.A scanning electron microscope (SEM), dispersive spectroscopy (EDS), X-ray diffraction (XRD), and mechanical tests (microhardness and wear) were used to identify the coating properties, morphologies, and phases.The findings showed that the addition of 5 g/l MoSi 2 increased the thickness and hardness of MAO coatings from 19.08 µm and 910 HV to 33.12 µm and 1260 HV, respectively.Also, the wear resistance by means of weight losses of uncoated alloys enhanced by 68% and 100% after MAO and 5 g/l MoSi 2 modified-MAO coatings, respectively.Results of this work will promote future works in using of industrial wastes in surface engineering of Ti-6Al-4V alloys by MAO technique for wear resistance applications.