Electrospark deposition of boron carbide powder on titanium alloy Ti-6Al-4V

Titanium alloys are indispensable in the aerospace, nuclear and automotive industries due to their high specific strength, excellent creep resistance and corrosion resistance, but their use is seriously limited due to poor wear resistance. The method of еlectrospark deposition using a non-localized electrode consisting of a mixture of titanium granules with the addition of 6 –12 vol.% boron carbide powder was used to obtain metalloceramic coatings Ti-TiB2 / TiC onto Ti-6Al-4V titanium alloy. The results of the study show that the coatings contain αTi, TiB, TiB2 and TiC phases. It was found that with an increase in the content of boron carbide powder in the electrode to 12 vol.%, the total ceramics concentration increases to 93 vol.%. According to the metallographic analysis data, the coating thickness varied from 43.6 to 57.6 μm. The Vickers microhardness of the coatings increased monotonically from 8.13 to 12.02 GPa with increasing ceramic concentration. The use of the developed coatings allows increasing the wear resistance of the surface of the Ti-6Al-4V titanium alloy by 48 and 71 times at loads of 25 and 50 N, respectively. The technology is proposed for applying metal-ceramic coatings to the Ti-6Al-4V alloy using B4C powder, which surpasses the corresponding laser coatings in hardness and wear resistance due to a many times higher concentration of reinforcing phases: TiB2 and TiC.