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Post-processing of additively manufactured components, including the removal of support structures and the reduction in surface roughness, presents significant challenges. Conventional milling struggles to access internal cavities, while the Self-Terminating Etching Process (STEP) offers a promising solution. STEP effectively smooths surfaces and dissolves supports without substantial changes in geometry. However, it can lead to compositional changes and precipitation, affecting the material properties and necessitating a design strategy to mitigate them. In this study, STEP is applied to stainless steel 316L (SS316L) produced via laser powder bed fusion, reducing surface roughness from 7 to 2 μm. After STEP, the surface carbon exhibited a threefold increase, leading to the formation of M23C6 clusters. This significantly impacted the yield strength, resulting in a 37% reduction compared to the as-built condition. The key to overcoming this challenge was using computational simulations, which guided the determination of the decarburization conditions: 1000 °C for 60 min, ensuring maximum M23C6 dissolution and surface carbon reduction with minimal grain coarsening. Following these conditions, the yield strength of SS316L was restored to the level observed in the as-built condition. These findings underscore the potential of the proposed design strategy to enhance the mechanical performance of additively manufactured components significantly. 

The Virtual Instrument Software Architecture (VISA)(National Instruments, 2021, 2022c; Wikipedia Contributors, 2021) is a simple Application Programming Interface (API) to com- municate with test and measurement instrumentation from a computer. VISA includes specifications for communicating with resources or instruments over GPIB (General Purpose Interface Bus, IEEE-488) and VXI (VME eXtensions for instrumentation), which are test and measurement specific I/O interfaces along with providing protocols for communicating over PC-Standard I/O standards, such as VXI-11 (over TCP/IP), UCSBTMC (USBTest and Measurement Class, over USB), HiSLIP (High Speed LAN Instrument Protocol).(Wikipedia Contributors, 2021) VISA’s ability to communicate with a wide variety of instruments over a broad range of I/O’s using a common set of APIs makes it an attractive communication API for scientists and equipment manufacturers to write equipment control software with. 

Advances in selective laser melting (SLM) of metals in the past two decades have made metals additive manufacturing more accessible for industrial adoption. Despite printing process improvements, post- processing of SLM components has not improved much, resulting in considerable costs, delay, and design limitations. Building upon recent advances in sensitization-based self-terminating etching processes, this work details a new set iodine-based sensitization and etching chemistries that simplify the post-processing of copper (Cu) alloy components fabricated using SLM. This work demonstrates that iodine can be used to ‘‘sensitize’’ the surface of copper alloy components to form soluble copper iodide salt that can be then dissolved in common solvents, such as acetonitrile. This process removes a predefined amount of material from all interior and exterior surfaces in a self-terminating manner, enabling facile removal of internal and external supports, removal of any trapped powder, and the smoothing of interior and exterior surfaces. We demonstrate this process on GRCop (Cu-chromium-niobium) alloys due to their widespread use by the rocket propulsion industry along with a demonstration in copper (110) for applications in heat exchangers and electromagnetic transmitters/receivers. Our results provide the first systematic study on the effect of iodi- zation temperature and duration on the thickness of the iodide region in GRCop-84 components. Additionally, the surface roughness before and after each iodization–dissolution was also quantified for GRCop-84 and showed 70% reduction in Ra roughness from a high of 10 lm as-printed to a low of 3 lm after four iodization-dissolution cycles.