Joining SiC Ceramics with Ti₃SiC₂/Ti_xC_y Multi-Interlayer by Spark Plasma Sintering

Abstract

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 TiH2, Si and C mixture powders by SPS from 1150 to 1450 °C for 10 min. The microstructure of SiC joints was observed by scanning electron microscopy (SEM), and 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. The results showed that the microstructure and phase composition of the joints depended on the joining temperature. A dense joint could be obtained above 1250 °C. Ti3SiC2 and TixCy were found in all joints. Also, the decomposition of Ti3SiC2 occurred in the 1450 °C joint. The highest shear strength of 80.5 ± 7.4 MPa was obtained in the 1350 °C joint. The fracture occurred within the joining interlayer and SiC ceramics during shear test, except for the 1150 °C joint, which existed obvious cavities in the joint.