Efficient optimisation of machining processes based on technical specifications for surface roughness: application to magnesium pieces in the aerospace industry

Magnesium is one of the lightest metallic materials and is well known and widely used in the aeronautic and aerospace industries. The pieces machined in these industrial fields must satisfy stringent surface roughness requirements to achieve a product quality that conforms to the design specifications. The aim of this investigation is to optimise efficiently the dry turning of magnesium pieces to achieve a surface roughness within technical requirements. A cost-effective and flexible statistical optimisation procedure, which is based on the technical specifications of surface roughness as well as on a robust experimental design, identified different optimal cutting conditions that provide a surface finish which meets the roughness specifications in magnesium parts. Furthermore, as a consequence of such optimisation procedure, the machining time was reduced, and the aerospace companies could select among the optimal operating conditions by also considering productivity, safety and environment criteria to control production of the surfaces finish.