Expanding the scope of SiC ceramics through its surface modification by different methods

Controlling the surface wetting of silicon carbide (SiC) ceramics is an urgent problem as its solution will significantly expand the scope of this material. In this work, the submicron SiC ceramics was obtained from the ultradispersed SiC powder fabricated by the plasma dynamic synthesis method. The bulk SiC samples were produced by spark plasma sintering at 1600 °С, 1700 °С, and 1800 °С. The effect of sintering temperature and promising methods of surface modification on wetting, elemental composition and surface roughness of SiC ceramics was studied. The surface modification methods included polishing, laser texturing, low-temperature annealing, magnetron chromium sputtering, and their combination. To predict the type of a texture formed after nanosecond laser radiation, the graphic-analytical method was developed. The best hydrophilic properties of SiC ceramics (the contact angle decreased to 9.3°) were obtained after polishing with subsequent nanosecond laser texturing. The best hydrophobic properties of SiC ceramics (the contact angle increased to 135.3°) were obtained after a combination of polishing, laser texturing, and magnetron chromium sputtering. Controlling the surface wetting of SiC ceramics from hydrophilic to hydrophobic makes it possible to significantly expand the scope of this material, for example, to use it in drop cooling systems of advanced digital devices that emit ultrahigh heat fluxes up to 1000 W/cm2.