Joining SiC Ceramics with Ti_3SiC_2/Ti_xC_y Multi-Interlayer by Spark Plasma Sintering

摘要

Spark plasma sintering (SPS) is a promising method to obtain robust silicon carbide (SiC) joint at a relatively low temperature within a short time. In this work, the joint of SiC ceramics was prepared with TiH_2, Si and C powder mixture by SPS from 1150 to 1450 °C. The microstructure of SiC joints was observed by scanning electron microscopy (SEM). The phase composition of the interlayer was determined by X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The mechanical properties of SiC joints were evaluated by the single lap shear test. Results showed that the microstructure and phase composition of the joints were related to the joining temperature. A dense joint could be obtained above 1250 °C. Ti_3SiC_2 and Ti_xC_y were produced in all joints. The highest shear strength of 80.5 ± 7.4 MPa was obtained in the 1350 °C joint. Also, the decomposition of Ti_3SiC_2 occurred in the 1450 °C joint and the content of Ti_xC_y increased, of which lowered the shear strength. The fracture occurred within the joining layer and SiC ceramics during shear test. Different fracture modes of the joint was observed to further clarify the relationship between shear strength and joining temperature.