(1. 合肥工業(yè)大學 材料科學與工程學院，合肥 230009；
2. Chemical Sciences and Materials Systems Laboratory, General Motors Research and Development Center,
Warren, MI 48090-9055, USA)
摘 要: 利用壓鑄工藝將液態(tài)鎂和固態(tài)鋁液-固復合是鎂/鋁異種材料連接的新工藝，進行鋁合金表面氧化膜去除工藝的研究，并在此基礎上，利用自制的液固雙金屬復合裝置將液態(tài)鎂合金AM60與處理后的固態(tài)鋁合金A390進行液固復合。研究鋁合金表面處理對液態(tài)AM60/固態(tài)A390液固復合工藝的影響，分析研究復合試樣界面的組織和性能。結果表明：采用鋁合金表面處理工藝能有效地去除A390鋁合金表面的氧化膜，同時在其表面形成一層含La2O3的包覆層。包覆層一方面可保護鋁合金表面，避免再次被氧化；另一方面包覆層中的La2O3又可以改善液態(tài)AM60/固態(tài)A390復合界面的組織，提高界面結合強度。AM60/A390的液固復合界面的抗剪強度最高可達78.4 MPa。經過固溶處理之后，可將強度提高到84 MPa。
關鍵字: 鋁合金；表面氧化膜；La2O3；AM60/A390復合；液固擴散焊接；界面組織
（1. School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China;
2. Chemical Sciences and Materials Systems Laboratory, General Motors Research and Development Center,
Warren, MI 48090-9055, USA）
Abstract:The die-casting is a new magnesium/aluminum dissimilar welding process via casting liquid Mg alloy onto solid Al alloy substrate. The process of removing the oxide layer on solid Al substrate surface was investigated, and on this basis, the melt magnesium alloy AM60 onto solid aluminum alloy A390 was overcastted by using home-made liquid-solid bimetal composite device. The experimental results indicate the surface treatment effectively removes the nature oxide layer on solid Al substrate surface, meanwhile, a layer containing La2O3 forms on the substrate surface. On the one hand, the coating can make aluminum alloy avoid re-oxidation. On the other hand, the La2O3 in the coating can improve the structure and the bonding strength of the interface of AM60/A390 bimetals. The optimal shear strength of diffusion bonding is achieved 60.6 MPa. After solution treatment, the shear strength increases to 84 MPa.
Key words: aluminum alloy; surface oxide layer; La2O3; AM60/A390 compound; liquid-solid diffusion weld; interface structure
