高体积分数SiC_P/6063Al复合材料真空钎焊工艺及润湿机理研究

Study on Vacuum Brazing Process and Mechanism of High Volume Fraction SiC Particle Reinforced Aluminum Matrix Composite

采用Al-Si-Cu-Mg-Ni五元合金钎料对60vol%SiC P/6063Al复合材料进行真空钎焊,研究了钎焊温度和保温时间对其接头剪切强度的影响,并利用金相显微镜、扫描电镜及能谱分析的方法对接头形貌及界面组织进行了观察分析。结果表明,随着钎焊温度和保温时间的增加,熔融钎料对复合材料的润湿性提高,钎料通过扩散与基体形成冶金结合,在565℃保温12 min后,接头剪切强度最大89.6 MPa,但在高温下随着保温时间的延长,钎缝中Mg元素蒸发聚集形成气孔,从而导致接头结合强度降低。

The brazing temperature and holding time influence the shear strength of the bonds made in 60vo1% SiCp/6063Al composite, using an aluminium based filler alloy containing Cu, Si, Mg and Ni. The microstructure of the welded joints was studied by metallographic microscope, scanning electron microscopy and energy spectrum analysis（EDS）. The results show that the brazing joints get a high-qunality under the condition of 565℃, holding time of 12min ,due to the brazing filler spreading fully and the shear strength can reach the top of 89.6 MPa. The wettability increases with increasing brazing temperature and holding time. But too longer holding time can result in the evaporation and aggregation of magnesium in the bonds which can decrease the strength.