A Novel Benchtop Open-Architecture Direct Energy Deposition System (BenchDED): Design, Manufacturing, Optimization, and Characterization
Additive manufacturing (AM) promises to change the way manufacturing companies do business in terms of product to market, complexity of manufactured parts, waste reduction, etc. AM technologies, which include laser-based powder-bed fusion (PBF) and direct energy deposition (DED), have been used successfully for producing near net shape complex metal parts; however, the cost of equipment, the cycle time, and the cost of parts can be prohibitively high. As a result, AM is not considered to be a sufficiently mature process for production. DED technology can be used in unique applications, such as part repair and cladding, and 3D printing of functional grading materials. Further investigations into the design and operation of DED are required to optimize equipment and cycle costs. The primary objective of this research is to investigate the feasibility of developing a low-powered, low-cost DED system. Phase one of this work involved designing and manufacturing a DED experimental setup to enable research and development. The BenchDED is a 200-watt DED modular and open architecture laser printer that was built in house at the Advanced Manufacturing Lab (AML). The BenchDED enables data collection and process monitoring. The knowledge and experience gained from the BenchDED were invaluable and helped to better understand the mechanics of the DED process. The second phase involved optimizing and tuning the BenchDED so that it would be able to create 3D printed parts. This phase involved refining the main components of the BenchDED. It also involved identifying the operating range for these components. The third phase of this research involved the microstructural analysis and mechanical characterization of the test coupons manufactured using both the BenchDED and commercial AM machines. A comparison of the microstructure of the different coupons confirmed the functionality of the BenchDED. The microstructural analysis of SS316L steel revealed that the grain structure and the hardness values for both the industrial and the BenchDED samples were comparable. The primary discrepancy was seen in the irregularity in the grain size, due to the difference in spot size used for the industrial samples ( 3 mm ) and the BenchDED samples ( 0.5 mm ).