The preparation method and application of aluminum alloy flux-cored wire for wire arc additive manufacturing

Ceramic phase modification is a effective method to improve the performance of wire arc additive manufacturing (WAAM) aluminum alloy component. In this paper, a preparation method of ceramic aluminum alloy flux-cored wire was developed. An advanced apparatus was developed for the preparation of flux-cored wires. The preparation system comprises three integral units: a wire forming module, a drawing module, and a coiling module. The wire forming module features a configuration of three forming rollers and three closed dies, while the drawing and reduction module incorporates 12 sets of wire drawing dies with varying diameters, with each stage maintaining a controlled compression ratio of 20%. The fluidization properties of the core powder mixture were systematically examined, revealing that optimal powder flow characteristics were achieved when the constituent particles were sized as follows aluminum particles at 300 µm, copper particles at 250 µm, and silicon particles at 200 µm. The pre-heat treatment parameters for the aluminum strip substrate were optimized, with the process conditions established as follows heating temperature of 230°C, soaking duration of 120 min, and air cooling as the cooling method. Through a sequential series of 12 drawing and reduction operations, a 1.2 mm diameter Al-Cu-NiO aluminum alloy flux-cored wire was successfully fabricated. During the WAAM process employing the developed Al-Cu-NiO flux-cored wire, the process exhibited stable arc combustion, consistent droplet transfer, and minimal spatter. The developed flux-cored wire was successfully utilized to fabricate the aircraft skin, demonstrating high formability and suitability for such applications.