Structural and Mechanical Properties of SiC-Rich By-Products of the Metal Grade Si Process

Abstract

Mechanical properties of composites produced from the SiC-rich furnace slag using traditional stone and ceramic machining technologies were studied. A non-uniform mixture of coarse monocrystalline SiC grains soaked with Si-metal and glassy oxide phases represented the microstructure of dense monolithic SiC-rich samples. The fracture mechanism of coarse-grained SiC-rich composites was susceptible to the grain size/sample geometry and machining conditions yielding flexural strength in the range of 50-106 MPa and high compression strength of 750 MPa. Despite inhomogeneous macro and microstructure, mechanical and thermal properties are comparable to the traditionally produced siliconized SiSiC ceramics. It opens up the opportunity for the circular economy and value-added recycling of the Si/FeSi industries’ wastes.