Laser Deposition of Metals for Shape Deposition Manufacturing

A laser/powder deposition process has been added to the Shape Deposition Manufacturing system at Stanford University. This process is more robust than previous SDM metal deposition processes, consistently producing fully dense, near-net shape deposits with excellent material properties Material is deposited by scanning the laser across a surface while injecting metallic powders into the melt-pool at the laser focus. A number of parts have been produced with the system, including an injection molding tool, multimaterial structures and simple mechanisms. Currently research is being perfonned to improve the finish quality of the parts. One of the main areas of research involves controlling thermal stresses which can lead to warpage and delamination. Selective deposition techniques and the use of low coefficient of thennal expansion materials such as INVARTM show promise for reducing defonnations caused by internal stresses.Mechanical Engineerin