Green state joining of SiC without applied pressure

External pressure (uniaxial or isostatic) is usually necessary to form a th in and defect-free joint in green state joining of Sic ceramics. A successf ul method of joining Sic in the green state using a liquid polymer precurso r, allylhydridopolycarbosilane (AHPCS), without applied pressure, is descri bed. The thermal decomposition behavior of the polymer was examined, and de fect formation during joint evolution was investigated by interrupting the heat treatment at various stages. Cracks and pores were observed in the joi nts formed by pure AHPCS during the pyrolysis of the polymer precursor. Add ing Sic powder to the joining paste eliminated defect formation. Optimum Si c loading in the paste was determined to be in the range of 25-35 vol%. Joi nts formed by AHPCS + (SiC + 5 wt% B) paste were essentially indistinguisha ble from the matrix and had an average strength of 323 MPa, comparable to t hat of the control sample.