粉末夾層瞬間液相擴(kuò)散焊接工藝
(1. 哈爾濱工業(yè)大學(xué) 金屬精密熱加工國(guó)家重點(diǎn)實(shí)驗(yàn)室，
哈爾濱 150001；
2. 大連理工大學(xué) 材料工程系， 大連 116024)
摘 要: 采用質(zhì)量比為2∶1的鋁銅混合金屬粉末作為中間夾層，通過(guò)TLP擴(kuò)散焊接工藝焊接了SiCw/6061Al鋁基復(fù)合材料。結(jié)果表明， 在真空度為1.33 Pa、 焊接預(yù)緊力20 MPa的條件下，最佳工藝參數(shù)為： 焊接溫度620 ℃，保溫時(shí)間60 min。 采用掃描電鏡研究了焊縫的微觀(guān)組織， 發(fā)現(xiàn)較低溫度下焊縫存在較多的孔洞。 用電子探針?lè)治龊缚p周?chē)胤植迹Y(jié)果表明， 在焊縫處富集較多的氧元素和鎂元素。 這是因?yàn)榛w鋁合金中的鎂與銅粉顆粒表面的氧化銅以及焊接工件表面的氧化膜（Al2O3）發(fā)生置換反應(yīng)，生成細(xì)小的MgO和Al2MgO4顆粒。該反應(yīng)有利于減小氧化膜的影響， 提高接頭強(qiáng)度。
關(guān)鍵字: 鋁基復(fù)合材料；瞬間液相； 擴(kuò)散焊接； 粉末夾層
（ 1. National Key Laboratory for Precision Hot Processing of Metals,
Harbin Institute of Technology, Harbin 150001, China;
2. Department of Materials Engineering,
Dalian University of Technology, Dalian 116024, China）
Abstract: Using aluminum powder and copper powder as pulverous interlayer, Albased composite SiCw/6061 was welded by transient liquid phase bonding. Mass ratio of aluminum powder and copper powder is 2∶1, vacuum degree is 1.33 MPa, and retightening load is 20 MPa. The result of experiment shows that the optimum process parameters are: welding temperature 620 ℃, holding time 60 min. Observing with scanning electronic microscope, many holes are found at weld lines if works pieces are welded at lower temperature. Distribution of elements around weld line is analyzed with electronic probe. The results indicate that O and Mg is enriched at weld line. Magnesium within aluminum alloy reacts with CuO and Al2O3 to produce MgO particles and Al2MgO4 particles respectively, which is favorable for restraining the effect of oxide film and enhancing mechanics properties of welded joints.
Key words: Al-based composite； transient liquid phase(TLP)； diffusion welding； pulverous interlayer
