| This paper explores milling brazing technology to2024aluminum alloy and Q235low carbon steel. The principle of the process of welding by milling the surface of theoxide film. Brazing alloy in combination with fresh surface of the steel. Oxide film on thealuminum surface is washed and crushed by the flow of the liquid brazing alloy.Metallurgical combine by diffusion and melting occurs at brazing alloy and aluminum.Prepared zinc-aluminum alloy (ZA12) for milling brazing by self. Shear strength is178.1MPa.Milling process parameters of brazing preliminary was investigated. Milling capacity,welding temperature, milling and welding speed are as variable in turn. And theirinfluences on welding quality were studied, respectively. The optimum parameters are asfollows:0.06mm milling capacity,450℃soldering temperature,5440rpm milling speed,20mm/min welding speed.In the protective gas weld Based on the above optimum parameters. Brazing jointform well, But there are a lot of porosity. Zinc and aluminum elements diffuse to the steelinterface. Steel side interface generate bright layer containing Feã€Al and Zn elements.Milled steel scraps metallurgically bond with solder, Zinc diffuse to2024aluminum. Steelside interfacial shear strength is140.7MPa. Filler metal Shear strength is123.8MPa. TheSide of Aluminum interfacial shear strength is159.7MPa, Steel side interface fractureoccurs in the pores. Al-Fe intermetallic compound can be found at fracture of steel saidinterface. The same ductile fracture at filler metal and aluminum side interfaces.Research milling process base metal brazing surface oxide film Broken and interfaceConnection process by pointing milling Brazing. Establish the oxide film crushing andmilling brazing interface with the physical model of the process.The main drawback milling brazed joints is the presence of a large number ofblowhole in the filler metal. Blowhole is the main factor to limit the mechanical propertiesof milling brazed joints. |
