铝基活性钎料真空钎焊C_f/C复合材料焊接接头的组织及性能

Microstructure and Properties of Vacuum Brazing C_f/C Composites Using Reactive Al Based Filler Metals

用铝基活性钎料对Cf/C复合材料进行真空钎焊,并对接头的微观组织、形成机理和接头强度进行了试验研究。结果表明,使用铝基活性钎料可以实现Cf/C复合材料的连接,且在试验温度范围内,接头强度随钎料成分不同而发生变化。电子探针观察表明,钎料与Cf/C复合材料钎焊接头润湿性良好,存在成分偏聚层,这种层状结构对缓和焊接残余应力十分有利。室温下接头最高剪切强度可达16MPa。

Vacuum brazing experiments of Cf/C composites were carried out using pure AI arid Al-STi-B as filler metals. The microstructurc of the brazing joints were studied by means of scanning electron microscopy （SEM） and energy dispersive X-ray spectrometer, the shearing strength of the joints were measured. The joining mechanisms were explored. The results indicate that the brazing temperature is the important processing parameter affecting the quality of the brazed joints. Vacuum brazing of Cf/C composites can be achieved using the pure Al and Al-STi-B brazing fillers at the brazing temperature of 730 or 750 ℃, respectively. Moreover, the joints have excellent microstructure and shear strength gets the level of practical applications up to 16MPa.