Mechanical properties of SiC-C-B 4 C composites with different carbon additives produced by pressureless sintering

摘要

In this research, carbon sources (Resin Phenolic, Carbon Black and Graphite) and Boron Carbide (B4C) were used to improve the mechanical properties of Silicon Carbide (SiC) composite. For this purpose, carbon sources of 0.5, 0.75, 1, 1.5, 2, 2.5, 3, and 5 wt% as well as 0.5 wt% B4C were added to SiC powder, respectively. The sample containing SiC-2.5 wt% Resin Phenolic-0.5 wt% B4C had the best properties with relative density, hardness, and fracture toughness values of 98.5%, 2820 GPa, and 3.9 MPa.root m, respectively. Examination of SEM images showed that by increasing carbon from 0.5 to 2.5 wt%, the fracture changes from intergranular to transgranular.