Reverse-Polarity Plasma Cutting of Thick Aluminum Alloy Plates

The paper investigates the structure and properties of the surface layers of AA5056 and AA2024 aluminum alloy plates 35 to 40 mm thick after reverse-polarity plasma cutting. It is shown that for alloys with varied parameters of the heat capacity, plasma cutting conditions are the same. At the best plasma cutting parameters, the cut geometry shows the lowest distortion. It is found that the cutting surface distortion occurs in exceeding the optimum heat input of the plasma arc. Conversely, at the reduced heat input, the alloy plate cannot be cut to its full thickness. Most of cutting modes provide the higher surface roughness, while the roughness of the upper edge cut reduces relative to the central and lower areas.