“…14. These results are in good agreement with those reported in literature [87][88][89]. Also, the presence of higher content of b-Si 3 N 4 with elongated grains enhances the fracture toughness due to the mechanism of crack bridging of the elongated grains [15,16,17,24,38,42,58,[73][74][75][78][79][80][90][91][92].…”