Design and Manufacture of Titanium Formula SAE Uprights Using Laser-Powder Deposition

摘要

Laser additive manufacturing technology allows the fabrication of complex metal components that would not be possible to make using conventional methods. Uprights play an important role in the performance of an open-wheel racecar suspension system by transferring forces from the tire to the vehicle frame and shock assembly. The upright design for the 2004 South Dakota School of Mines and Technology's (SDSM&T) Formula SAE vehicle that met all the proposed functional requirements was found using a comprehensive design process. It consisted of a thin-walled hollow structure with minimal supporting ribs that could not be manufactured by a single available conventional manufacturing method and thus was an ideal candidate for laser additive manufacturing. To fabricate this "shell" design, the SDSM&T's laser-powder-deposition (LPD) machine was employed. Deposition of pre-alloyed metal powder into the melt pool formed at the focal point of a laser with motion controlled by CAM-generated paths enables the formation of 3-D solid structures one layer at a time. This process was found to be ideal for producing hollow "shell" style components. In an effort to increase the suspension system performance of the 2004 SDSM&T Formula SAE racecar, FSAE team members utilized this technology to deposit Ti-6Al-4V into the most rigid set of uprights ever produced at this institution. They are almost an order of magnitude stiffer per unit weight than the machined aluminum structures used in the past.