(哈爾濱工業(yè)大學(xué) 現(xiàn)代焊接生產(chǎn)技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，哈爾濱 150001)
摘 要: 利用Al-Si-Mg釬料和自制工藝罩內(nèi)置Mg粉方法，實(shí)現(xiàn)化學(xué)鍍鎳Al2O3陶瓷與5A05鋁合金的真空釬焊連接，并分析保溫時(shí)間及連接溫度對(duì)接頭界面結(jié)構(gòu)和抗剪強(qiáng)度的影響。結(jié)果表明：連接溫度570 ℃，保溫時(shí)間15 min為最佳工藝參數(shù)，此時(shí)接頭界面結(jié)構(gòu)為Al2O3/Ni(Ⅰ區(qū))/Al3Ni2(Ⅱ區(qū))/Al3Ni+Mg2Si(Ⅲ區(qū))/α(Al)+Mg2Si(Ⅳ區(qū))/5A05，接頭的抗剪強(qiáng)度為25 MPa。隨著保溫時(shí)間的延長，Ni層變薄，Al3Ni2組織的變化不大，Al3Ni+Mg2Si組織逐漸變寬，且呈分散趨勢(shì)；當(dāng)保溫時(shí)間延長到50 min時(shí)，Al3Ni+Mg2Si完全變成零亂的形狀、大小不一的塊狀分布，且靠近5A05側(cè)的Mg2Si消失。連接溫度對(duì)界面組織結(jié)構(gòu)的影響與保溫時(shí)間的影響相似，接頭斷裂形式為脆性斷裂。當(dāng)接頭的強(qiáng)度較低時(shí)，斷裂發(fā)生在鋁合金側(cè)的α(Al)+Mg2Si附近；當(dāng)接頭的強(qiáng)度較高時(shí)，斷裂發(fā)生在鍍Ni層+界面區(qū)(Ⅱ區(qū)與Ⅲ區(qū))。
關(guān)鍵字: Al2O3陶瓷；化學(xué)鍍鎳；真空釬焊；界面結(jié)構(gòu)；抗剪強(qiáng)度
（State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology,
Harbin 150001, China）
Abstract: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).
Key words: Al2O3 ceramic; electroless nickel plating; vacuum brazing; interface structure; shear strength
