中文摘要：

采用含氢聚硅氧烷（HPSO）和含乙烯基聚硅氧烷（VPSO）2种陶瓷先驱体作为连接剂的主要组分,以Al-Si粉为填料,通过反应成形连接工艺连接无压烧结碳化硅。采用热重法、差示扫描量热法和X射线衍射法研究了Al-Si粉对HPSO和VPSO的混合物（HPSO-VPSO）的裂解过程和陶瓷产率的影响,同时也研究了Al-Si粉含量、升温速率及连接温度对连接强度的影响。并采用扫描电镜和能谱仪对连接件界面区域的微观结构和成分进行了分析。Al-Si粉的加入促进了HPSO-VPSO的裂解,提高了陶瓷产率。当HPSO-VPSO与Al-Si粉质量比为1∶1,连接压力为50 kPa,连接温度为900℃,高温保温时间为30 min,升温速率为4℃/min时,所得连接件的连接强度（剪切强度）达到最大值93 MPa。连接层厚度约为75μm,结构均匀致密,连接层与母材结合良好,在界面处没有明显的裂纹、孔洞等缺陷。Al、Si元素在连接层与无压烧结碳化硅的界面处发生了扩散,促进了界面结合,从而提高了连接强度。

英文摘要：

Joining of pressureless sintered SiC was carried out by the reaction joining process using the mixture of hydrogen-containing polysiloxane and vinyl-containing polysiloxane（denoted by HPSO-VPSO） with additive Al-Si powders as joining materials.The pyrolysis of HPSO-VPSO with Al-Si powders was studied by thermogravimetry,differential scanning calorimetry and X-ray diffraction.The effects of the joining temperature,the content of Al-Si powders and the heating rate on the joining strength of joints were investigated.The microstructure and composition of interfacial area were analyzed by scanning electron microscopy and energy dispersive spectrometry.The results show that the additive Al-Si powders promote the pyrolysis of HPSO-VPSO and lead to the increase of the ceramic yield per unit HPSO-VPSO.The maximum shearing strength of the joints is obtained to be 93 MPa at the joining pressure of 50 kPa,the joining temperature of 900 ℃,the holding time of 30 min,the heating rate of 4 ℃/min and the Al-Si powders mass fraction of 50%.Microstructure study reveals that the thickness of the interlayer is about 75 μm,and the contact at the interfaces is intact without obvious pores and cracks.The interdiffusion of Al and Si takes place at the interfacial area,which contributes to the interfacial bonding,resulting in the increase of the joining strength of the joints.