中文摘要：

利用Al-Si-Mg钎料和自制工艺罩内置Mg粉方法,实现化学镀镍Al2O3陶瓷与5A05铝合金的真空钎焊连接,并分析保温时间及连接温度对接头界面结构和抗剪强度的影响。结果表明：连接温度570℃,保温时间15min为最佳工艺参数,此时接头界面结构为Al2O3/Ni（Ⅰ区）/Al3Ni2（Ⅱ区）/Al3Ni＋Mg2Si（Ⅲ区）/α（Al）＋Mg2Si（Ⅳ区）/5A05,接头的抗剪强度为25MPa。随着保温时间的延长,Ni层变薄,Al3Ni2组织的变化不大,Al3Ni＋Mg2Si组织逐渐变宽,且呈分散趋势;当保温时间延长到50min时,Al3Ni＋Mg2Si完全变成零乱的形状、大小不一的块状分布,且靠近5A05侧的Mg2Si消失。连接温度对界面组织结构的影响与保温时间的影响相似,接头断裂形式为脆性断裂。当接头的强度较低时,断裂发生在铝合金侧的α（Al）＋Mg2Si附近;当接头的强度较高时,断裂发生在镀Ni层＋界面区（Ⅱ区与Ⅲ区）。

英文摘要：

Vacuum brazing of Al alloy and electroless nickel plated alumina was carried out with Al-Si-Mg brazing alloy and Mg powder in home-made technical hood.Effects of brazing temperature and holding time on the interface structure and shear strength of joints were analyzed.The experimental results show that the interface structure is Al2O3/Ni（Ⅰzone）/Al3Ni2 （Ⅱzone）/Al3Ni＋Mg2Si（Ⅲ zone）/α（Al）＋Mg2Si（Ⅳ zone）/5A05 when the brazing temperature is 570 ℃ and holding time is 15 min.The maximum shear strength of joints is up to 25 MPa.As the holding time prolongs,Ni layer becomes thin,Al3Ni zone changes little and Al3Ni＋Mg2Si zone becomes thick and dispersed.When the holding time is 50 min,Al3Ni＋Mg2Si zone becomes scattered and Mg2Si near 5A05 alloy disappears.The effect of brazing temperature on the joints is similar to that of holding time.The fracture mode of joints is brittle.When the shear strength of joints is lower,the joints fracture near α（Al）＋Mg2Si on Al alloy side.When the shear strength of joints is higher,the joints fracture on Ni＋interface （Ⅱzone and Ⅲ zone）.