A novel SiC composite material infiltrated by basalt glass-ceramic with a high hardness

New high-performance materials for environments with high abrasive and erosive loads resistant are in a great demand for the modern industry. For the first time, a composite material obtained by infiltration of SiC porous oxide bonded preform with a basalt rock melt at a temperature of 1400 degrees C in air was proposed. The produced composite material significantly reduces porosity from 31.0 to 1.2%. Interestingly, an aluminosilicate phases crystallizes on the surface of SiC grains meanwhile the migration of Ca and Fe to the melt basalt volume due to atomic radii mismatch with the forming phases. The crystallinity of the basalt glass matrix obtained by petrurgical method is 66.9%. All together allows to improve hardness of the obtained composite material SiC/basalt glass-ceramics from 2.6 (preform) and 6.8 (basalt glass ceramics) to >9.6 GPa. The composite material fracture toughness (K-1c similar to 0.85 MPa.m(1/2)) also increases in comparison to a highly fragile basalt glass ceramics matrix. Thermal expansion coefficient value of the produced composite material is close to the dense polycrystalline SiC one and no sample destruction was observed caused by materials TEC mismatch.