Mechanical properties of SiC‐C‐B₄C composites with different carbon additives produced by pressureless sintering

Abstract

In this research, carbon sources (Resin Phenolic, Carbon Black and Graphite) and Boron Carbide (B 4 C) 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% B 4 C were added to SiC powder, respectively.The sample containing SiC-2.5 wt% Resin Phenolic-0.5 wt% B 4 C had the best properties with relative density, hardness, and fracture toughness values of 98.5%, 2820 GPa, and 3.9 MPa.√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.

Indentation fracture resistance of brittle materials using irregular cracks: A review

“…Finally, the output of the equation for all ratios had an accuracy of over 90% compared to the relationships in Table 1 [ 85 ]. Also, in other studies, the amount of loading in B 4 C-nanoTiB 2 samples was considered a variable parameter, and no effect on the accuracy of the equation was observed before chipping [ 89 , 90 ]. However, there seems to be a need for extensive research in this regard.…”

“…However, so far, there have been no reports of inaccuracies in the equation outputs. In several studies, the accuracy for different materials has generally been more than 90% compared to CFM and VIF [ [79] , [80] , [81] , [82] , [83] , [84] , [85] , [86] , [87] , [88] , [89] , [90] ]. However, there is a need for more theoretical and practical use which can prove its accuracy, this will reduce the cost of testing and could be a new approach to determining the K IFR / K IC .…”