Effects of cryogenic cooling on cutting temperature and surface roughness in turning of AA7075 aluminum alloy

The machining process is one of the most widely used methods for converting raw materials into finished products across various industries, owing to its numerous advantages, such as high precision, the capability to produce complex geometries, and superior surface finish. AA7075 aluminum alloy is extensively utilized in the aerospace and automotive sectors due to its exceptional strength-to-weight ratio, moderate corrosion resistance, and fair machinability. During machining operations, the simultaneous imposition of mechanical and thermal loads, coupled with severe plastic deformation, induces changes in the material’s mechanical and metallurgical properties—these alterations must be considered to enhance the component’s performance. Consequently, the surface integrity of the machined part, encompassing metallurgical, mechanical, and topographical aspects, is of paramount importance. Surface roughness, a key indicator of surface texture, directly influences the fatigue life of the component. Employing techniques such as cryogenic cooling with liquid nitrogen can mitigate the temperature in the cutting zone, thereby enhancing surface quality and prolonging component lifespan. In this investigation, the impacts of various dry and cryogenic machining conditions on surface roughness and thermal loads were examined, and the influential parameters were identified.