Functional gradient metallic prototypes through shape deposition manufacturing

Stanford's SDM laser deposition system has been recently improved to enable the deposition of functionally graded metals through the use of powder mixing. While Shape Deposition Manufacturing has always had the capability to produce multimaterial artifacts, powder mixing enables the deposition of single layers in which material properties can be smoothly varied without discrete interfaces between dissimilar materials. It has been shown that certain materials will completely mix during deposition and form alloys which exhibit material properties intermediate to those of the constituent feed powders. To date, oxidation and hardness have been effectively controlled through appropriate mixing of powders. Functional gradient material deposition has been exploited to construct an advanced injection molding tool which transitions from Invar in the center to stainless steel on the outside. The resulting tool exhibited minimal distortion from thermal stress and excellent exterior corrosion resistance.