Design and fabrication by Selective Laser Melting of a LIDAR reflective unit using Metal Matrix Composite material

Abstract

The Selective Laser Melting is an Additive Manufacturing technology able to directly fabricate full dense metal part from a virtual model. The geometrical complexity degree of freedom allows the implementation to several industrial applications such as the Laser Imaging Detection and Ranging systems. A key component of this system is the reflective unit which must satisfy functional requirements and a weight reduction is advisable. Aim of this work is to reach these goals by using an integrated product/process methodology which considers all the fabrication steps. A complete redesign allowed to exploit the Additive Manufacturing advantages of a Metal Matrix Composite based on AA 2000 series combined with a high content of ceramic. The component was validated via Finite Element Method simulation focused on the most critical polishing operation. Results on static and dynamic analysis showed the lightened mirror satisfies the requirements. The testing on the physical prototype confirmed the enhanced mechanical properties and the interferometric measurement verified the mirror functionality. The work evidenced that particular care must be provided to the configuration used for the polishing and the assembly in this lightened component.