Machining behaviour analysis of PBF-LB warped components with internal lattice microstructures

Abstract

Metal additive Powder Bed Fusion, Laser Based (PBF-LB) manufacturing offers significant improvements in the design of complex parts of inner components areas for several sectors, from dies and moulds, to blades and aerofoils. Generating internal structures helps to move fluids, work as heat exchanges, or achieve dramatic weight relief, only possible by additive manufacturing, concretely PBF-LB. Along with these designs, sculptured surfaces and warped surfaces are also common in blades and other aerodynamic pieces. However, it is mandatory that these designs accomplish the final required mechanical properties without surface damage and non-admissible dimensional deviations. In this study, the five-axis milling of a part containing internal structures has been investigated. Two types of PBF-LB Inconel® 718 blades were manufactured, one solid and one with internal microstructures. They were finished using two types of ball-ended mills, ball and barrel-lens tooltip. The analysis of the blade with internal structures shows better machining behaviour, dynamic behaviour, and surface quality.