原位生成法半固态连接Si3N4复相陶瓷的接头组织

为探索陶瓷材料的有效连接途径,提出一种原位生成增强颗粒的半固态钎焊陶瓷材料方法。采用自制钎料对Si3N4复相陶瓷进行钎焊试验。采取分步焊接的方法,在1023K下使钎缝内生成一定数量的AlCu2Ti金属间化合物,然后在1173K下对陶瓷材料进行半固态连接。显微观察表明:钎缝组织由低熔点的钎料基体和高熔点的金属间化合物组成,金属间化合物均匀分布在钎料基体中,有利于改善接头性能,降低接头的热膨胀不均匀性。

Joints in Si3N4 ceramics bonded using solid-liquid state bonding with intermetallic compounds formed in situ

A solid-liquid bonding method was developed for ceramics formed in situ with reinforcing particulates to explore an effective way to bond ceramics. Si3N4 ceramics were brazed with self-made bonding materials. The bonding was conducted in two steps with some intermetallic AgCu2Ti first formed in the weld at a relatively low temperature and then solid-liquid state bonding of the ceramics achieved at a higher temperature. Scanning electron microscopic photographs of the microstructure show that the welds are composed of a base of low melting-point bonding materials and higher melting-point intermetallic compounds. The intermetallic compounds are homogeneously distributed in the matrix so they contribute to the decrease in thermal expansion mismatching and the improved joint properties.