Method for friction stir processing for the end surface of age-hardening aluminum alloy plates

A method for friction stir processing of an end surface of an age-hardening aluminum alloy plate, comprising:

• (1) butt-joining an age-hardening aluminum alloy plate after being subjected to solution treatment onto a dissimilar plate;
• clamping and fixing the age-hardening aluminum alloy plate and the dissimilar plate to obtain a combined plate;
• and arranging a weld-start plate at a first side of the combined plate and a lead-out plate at a second side of the combined plate;
• wherein the age-hardening aluminum alloy plate has a first end surface and a second end surface opposite to the first end surface;
• (2) arranging a stirring pin at a bottom end of a stirring head, maintaining a distance between an outer edge of the stirring pin and the first end surface of the age-hardening aluminum alloy plate to be 0.01-5 mm in a direction from the age-hardening aluminum alloy plate to the dissimilar plate, and rotating the stirring pin into the weld-start plate;
• (3) performing friction stir processing on the age-hardening aluminum alloy plate in an underwater condition or a liquid nitrogen cooling condition, wherein the first end surface is in direct contact with and abuts against the dissimilar plate in steps (1)-(3);
• and
• (4) separating the age-hardening aluminum alloy plate from the weld-start plate, the lead-out plate and the dissimilar plate, and performing aging treatment on the age-hardening aluminum alloy plate.