聚硅氧烷连接RBSiC陶瓷  

Joining of Reaction-Bonded Silicon Carbide Using a Polysiloxane

作　　者：刘洪丽[1] 李树杰[1] 陈志军 

机构地区：[1]北京航空航天大学,北京100083 [2]陕西华兴航空机轮刹车系统有限责任公司第46研究所,陕西兴平713106

出　　处：《稀有金属材料与工程》2006年第1期134-137,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金资助项目(50271003);中国航空基础科学基金资助项目(03H51024)

摘　　要：采用陶瓷先驱体有机聚合物聚硅氧烷连接反应烧结碳化硅（RBSiC）陶瓷。研究了连接温度、连接压力、保温时间对连接强度的影响。通过正交优选实验，确定了最佳工艺参数：连接温度为1300℃，连接压力为25kPa，保温时间为120min。在此工艺条件下制备的连接件经3次浸渍／裂解增强处理，其抗弯强度达132．6MPa，连接件断口表面粘有大量从母材剥离下来的SiC。XRD研究表明，在1100℃～1400℃的试验范围之内，随着连接温度的逐步升高，聚硅氧烷的裂解产物发生了由非晶态向晶态的转变。这种转变对连接强度有显著影响。扫描电镜（SEM）及能谱（EDX）分析显示，连接层厚度为3μm左右，结构较为均匀致密，且与母材间界面结合良好。Joining of reaction-bonded silicon carbide （RBSiC） to itself has been realized using a preceramic polymer, polysiloxane, as joining material. The joining strength of the joints is strongly affected by the technological parameters including joining temperature, joining pressure and holding time. The optimized technological parameters are 1300℃, 25 kPa and 120min. Infiltration/pyrolysis reinforcement can effectively enhance the joining strength. After the reinforcement for 3 times, the bending strength of the joints welded under the optimized conditions reaches 132.6 MPa. XRD analysis indicates that within the tested range of 1100℃-1400℃, the pyrolyzate of polysiloxane transforms from amorphous ceramic to crystal with the increase of the joining temperature. This transformation strongly affects the joining strength. Microstructural studies reveal that the joining interlayer is uniform and densified, of which the thickness is about 3 μm. Good contact at the interfaces is visible on the SEM photograph.

关 键 词：特种连接 陶瓷连接 陶瓷先驱体 聚硅氧烷 反应烧结碳化硅(RBSiC) 

分 类 号：TQ174.758[化学工程—陶瓷工业]