Method of friction stir welding aluminum alloy materials containing second phase particles, and aluminum alloy panel produced thereby

摘要

First and second aluminum alloy materials, each comprised of a 5000-series aluminum alloy containing second phase particles having a diameter less than 5 µm in a distribution density of less than or equal to 10,000 second phase particles/mm2, are welded together by abutting portions of the first and second aluminum alloy materials, and friction stir welding along the abutted portions to form an integrally-welded aluminum alloy panel. The friction stir welding is performed using a tool (8) having a shoulder (10) under the following conditions: (i) the shoulder (10) of the tool (8) has a diameter (d) in the range of 3 mm ≤ d ≤ 8 mm and (ii) the revolution number (r) of the tool (8) is 6 r ≤ 20, wherein r is tool revolutions/length of the weld (4) in millimeters.