Formation and Analysis of Dense Boron Carbide Coatings With a Low Porosity Formed by Electromagnetically Accelerated Plasma Spraying

Thick coatings, which are necessary for many industrial fields, are easily obtained using thermal spraying compared with other methods such as CVD and PVD. However, the porosity is relatively high in the spray coatings. The ambient gases passing through the many pores in the coating may damage a base substrate material, and the coating would be easily detached. We have obtained thick boron carbide (B4C) coating with a porosity of 3% using electromagnetically accelerated plasma spraying. In this study, by using smaller powder of 2 micron in diameter, dense B4C coatings are formed with a low porosity of less than 1%. The size of the pores is also drastically decreased.