Regulation layer for dissimilar metal friction welding interface and aluminum-steel friction welding method

An aluminum-steel friction welding method based on micro-texture and interlayer composite regulation, comprising:

• step 1, polishing an aluminum alloy base material and a stainless steel base material to remove oxide films from surfaces of base materials, and then performing cleaning and drying in sequence;
• step 2, preparing a micro-texture in a designated area on a surface of a stainless steel plate, and performing ultrasonic cleaning in absolute ethanol for 10 minutes to 15 minutes after completing preparation of the micro-texture;
• step 3, mixing a Zn-20Al powder and ethanol under stirring into a paste, then uniformly spreading the paste in a micro-texture area on the surface of the stainless steel plate, and then placing base materials to be welded on a welder bench in a lap joint manner with steel on top and aluminum on bottom, followed by locating and clamping using a fixture, wherein the paste is a mixture of the Zn-20Al powder and the ethanol, and a mass ratio of the Zn-20Al powder to the ethanol is 1:1.5;
• and
• step 4, performing friction welding using a friction stir welding machine to obtain an aluminum-steel friction welded joint, a stirring head of the friction stir welding machine being a needleless stirring head;
• wherein
• the aluminum alloy base material is 6061 aluminum alloy, and the stainless steel base material is 304 stainless steel;
• the micro-texture is machined using an ultra-fast laser system with the following machining parameters:
• a pulse width of 20 ns, a laser wavelength of 300 nm, a pulse repetition frequency of 20 kHz, a laser power of 10 W, a pulse energy of 0.5 mJ, a laser scanning rate of 20 mm/s to 80 mm/s, and a laser beam scanning area of 20 mm×20 mm;
• and
• the micro-texture obtained by machining features a groove with a width of 50 μm and a depth of 200 μm.