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Description
Since the years of the first semiconductor transistors and even more so after the popularization of miniaturization of machines by Richard Feynman, thin and thick films exhibit a great demand in the fields of electronics and MEMs. Additive manufacturing is a key step in the manufacturing of modern thick and thin film components for these industries. The following thesis presents, a novel rapid additive manufacturing process: Ballistic Manufacturing (BM). The process, as investigated in this effort, consists of accelerating a substrate through a molten curtain of metal producing a film coating. A San Diego State University built BM prototype machine was tested and the resulting films analyzed. Lead free solder (Sn-0.7Cu) was used as an initial testing material. Velocities of up to 37.1m/s and incidence angles from 5° to 30° were investigated as the main processing parameters in the present study. The increase in processing velocity was found to increase cooling rate, and decreases film thickness, and microstructure dimensions. Conversely the increase in incidence angle was found to decrease cooling rate, and increase film thickness, and microstructure dimensions. Thickness as low as 1.56_m were produced under the investigated processing parameters. The resulting films were crystalline in nature exhibiting 2D-hypoeutectic cellular structures with diameters ranging from of 70_m to 166_m depending on processing conditions. Relative cooling rates were calculated from the cell sizes with the use of dendrite arm spacing (DAS) cooling theories. Overall results prove the viability of BM as a new thick and thin film manufacturing process.
