采用快速甩带技术制备了7组(Al-33.3Cu-6.0Mg)-xNi(x=0,0.5,1.0,2.0,3.0,4.0,5.0,质量分数/%)急冷箔状钎料,分别对化学镀Ni-P合金前后的SiCp/A356复合材料进行真空扩散钎焊.通过剪切实验对钎焊接头的抗剪强度进行测定,并利用扫描电镜和能谱分析等方法对接头微观组织进行观察和分析.结果表明,当向Al-33.3Cu-6.0M g钎料合金中添加不同含量的Ni时,其急冷钎料的固-液相线(504~522℃)变化较小;当w(Ni)=3%且在570℃ 、保温30 min的钎焊工艺下,A356基体/钎料两界面间发生适当的互扩散和溶解现象(585℃时出现溶蚀缺欠),且部分钎料/SiC颗粒的接触界面发生M g参与的化学反应,接头抗剪强度达到64.97 M Pa;而在同种钎焊工艺下,对于化学镀Ni-P合金镀层后的SiCp/A356复合材料,其接头处A356基体/Ni-P合金镀层/钎料等接触界面易于形成富含Al、Ni的致密反应层,接头连接质量显著提高,且w(Ni)=4%时,接头抗剪强度达到79.96 M Pa.%Using (Al-33 .3Cu-6 .0Mg)-xNi (wt .% x=0 ,0 .5 ,1 .0 ,2 .0 ,3 .0 ,4 .0 ,5 .0) filler metal foils obtained by rapidly melt-spun technique ,vacuum brazed joints of 55% SiCp/A356 composites with and without electroless Ni-P alloy coating were obtained ,and their microstructures and bonding strength were analyzed by SEM ,EDS and shearing test respectively .Results show that the solidus-liquidus temperatures of the developed foils are close to 504—522 ℃ . Without Ni-P alloy coating and using (Al-33.3Cu-6 .0Mg)-3Ni filler metal ,compact joints were obtained at 570 ℃ and soaking time of 30 min and its shear strength achieved to 64 .97 MPa .In the case ,proper interdiffusion and dissolution between A356 matrix/filler metal interfaces occurred rather than defect of melting corrosion at 585 ℃ ,and reaction layer was obtained along the part of filler metal/SiCp interfaces because of chemical reaction with active Mg element effect .While with Ni-P alloy coating ,compact reaction layers rich in Al and Ni elements tended to be formed along the A356 matrix/Ni-P alloy coating/filler metal foil interfaces at 570 ℃ and soaking time of 30 min . Consequently ,the joint adhesion was improved significantly and a higher shear strength of 79 .96 MPa was obtained by using (Al-33 .3Cu-6 .0M g )-4Ni filler metal foil .
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