Mechanical Engineering Commons^™

Unmanned Research Raft, Jacob Davis, Andrew Fleming, Luke Vickerman, Kahye Yu

Mechanical Engineering

This document serves as the Final Design Review report for the design team conducting the research raft design project for Lawrence Livermore National Lab (LLNL). Our team has taken on a project to design a new research raft for LLNL.

The current rafts are suitable, but engineers have modified and altered the rafts to add more features as needed. This has led to a raft that accomplishes mission goals, but still has room for streamlining. The battery technology has also improved. Our goals were to redesign the raft from the ground up, reducing the size and weight. We also wanted …

Metals Additive Manufacturing Powder Aging Characterization, Thomas Russell Lovejoy, Nicholas Karl Muetterties, David Takeo Otsu

Mechanical Engineering

The metallic additive manufacturing process known as selective laser melting requires highly spherical, normally distributed powder with diameters in the range of 10 to 50 microns. Previous observations have shown a degradation in powder quality over time, resulting in unwanted characteristics in the final printed parts. 21-6-9 stainless steel powder was used to fabricate test parts, with leftover powder recycled back into the machine. Powder samples and test specimens were characterized to observe changes across build cycles. Few changes were observed in the physical and mechanical properties of the specimens, however, there were indications of chemical changes across cycles. Potential …