Influence of Reverse-Polarity Plasma Cutting Parameters on Structure and Surface Roughness of Aluminum Alloys

The paper focuses on plasma cutting of AA5056 and AA2024 aluminum alloy sheets. It is shown that at the minimum thicknesses, the upper edge of the sheet tends to undercut when using reverse polarity. This phenomenon considerably diminishes when using the best cutting conditions. In the case of the AA2024 alloy, most of the material remains in the cutting zone, adhering to the surface and forming a substantial zone of melting or beading. The AA2024 alloy demonstrates a greater oxidation and hardening of the cutting surface. Degraded material layers and surface roughness reduce when using the best cutting conditions. The upper edge of both alloys is more homogeneous and exhibits less roughness than the lower edge. This is attributed to a more complex displacement of the metal relative to the lower edge undercut.