Ultrasonic auxiliary vacuum electron beam welding method of aluminum and aluminum alloy

Abstract

The invention discloses an ultrasonic auxiliary vacuum electron beam welding method applied to aluminum and an aluminum alloy, which can solve the technical problem that the aluminum, the aluminum alloy and especially cast aluminum alloy generate cavity type defects such as air hole, cold laps and the like in the process of welding a vacuum electron beam so as to improve mechanical properties of welding joints. In the technology, structural load ultrasonic energy with certain frequency and certain amplitude is applied in the process of welding the vacuum electron beam, the ultrasonic frequency is between 15 and 50 kHz, and the amplitude is between 10 and 50 mu m. A molten pool and adjacent areas thereof generated by welding the vacuum electron beam are continuously oscillated to a certain extent, so that the cavity type defects such as the air hole, the cold laps and the like can be effectively eliminated in the process of welding to obtain high quality welding joints.

Description

technical field [0001] The invention relates to an ultrasonic-assisted vacuum electron beam welding method for aluminum alloys, which is suitable for welding aluminum and aluminum alloys, especially cast aluminum alloys. Background technique [0002] Aluminum and aluminum alloys are widely used in aviation, aerospace, automobiles, Locomotives, machinery manufacturing, shipbuilding, chemical industry, national defense and military and other fields have extremely important application value and broad application prospects. [0003] There are many methods that can be applied to aluminum and aluminum alloy welding, including gas welding, TIG welding, MIG welding, plasma arc welding, electron beam welding, laser welding, resistance welding, friction welding, diffusion welding, brazing and composite heat source welding, etc. Various methods have their different application occasions. Due to the unique physical and chemical properties of aluminum and aluminum alloys, such as easy ...

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Problems solved by technology

[0006] 3. Large linear expansion coefficient: The linear expansion coefficient of aluminum is about twice that of steel, and the crystallization shrinkage rate during solidification is also very large. It is easy to produce welding deformation and internal stress during the welding process. Therefore, when welding aluminum alloys with high rigidity Cracks are prone to occur in the structure

[0008] 5. Low strength and plasticity at high temperature: At high temperature, the strength and plasticity of aluminum are so low that it cannot support the liquid metal and the weld is poorly formed, sometimes causing the weld metal to collapse or burn through

[0009] 6. Evaporation and burning loss of alloying elements: Some aluminum alloys contain alloying elements with low boiling points, such as magnesium and zinc. The chemical composition of the seam metal changes so as to degrade the performance of the welded joint

[0010] 7. No color change: During the welding process, when aluminum and aluminum alloys change from solid to liquid, unlike steel materials, there is a significant color change, which makes it difficult for welding operators to control the heating temperature

However, the electron beam defocusing welding process affects the energy density distribution of the electron beam welding heat source, reduces its deep penetration ability, and obtains a shallower penetration depth of the weld. In some deep penetration welding occasions, the required once Welding Forming Effect

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