Shear strength and shear-induced Hertzian contact damage in Ti_3SiC_2 were investigated using double-notched-beam specimen and steel spherical indenter, respectively. The shear strength of 40 MPa that was only about 1...Shear strength and shear-induced Hertzian contact damage in Ti_3SiC_2 were investigated using double-notched-beam specimen and steel spherical indenter, respectively. The shear strength of 40 MPa that was only about 10% of bending strength was obtained for this novel ceramic. The SEM fractograph of specimens failed in shear test indicated a combination of intergranular and transgranular fracture. Under a contact load, plastic indent without cone crack could be formed on the surface of Ti3SiC2 sample. Optical observation on side view showed half-circle cracks around the damage zone below the indent, and the crack shape was consistent with the contrail of the principal shearing stress. The low shear strength and the shearing-activated intergranular sliding were confirmed being the key factors for failure in Ti3SiC2.展开更多
基金This work was supported by the National Outstanding Young Scientist Foundation(No.50125204 for Y.Bao and No.59925208 for Y.Zhou)“The Hundred-Talent Program”of Chinese Academy of Sciences and“863”program in China.
文摘Shear strength and shear-induced Hertzian contact damage in Ti_3SiC_2 were investigated using double-notched-beam specimen and steel spherical indenter, respectively. The shear strength of 40 MPa that was only about 10% of bending strength was obtained for this novel ceramic. The SEM fractograph of specimens failed in shear test indicated a combination of intergranular and transgranular fracture. Under a contact load, plastic indent without cone crack could be formed on the surface of Ti3SiC2 sample. Optical observation on side view showed half-circle cracks around the damage zone below the indent, and the crack shape was consistent with the contrail of the principal shearing stress. The low shear strength and the shearing-activated intergranular sliding were confirmed being the key factors for failure in Ti3SiC2.
