ADVANCED MATERIALS & PROCESSES | MARCH 2025 20 density cube include characterizing the thickness of walls, density resulting from geometry changes or the trueness of horizontal through-holes, as well as large cross-sections. Such variations provide unique opportunities for innovative fixturing, mounting, polishing, and microscopic techniques. Delicate samples or large monolithic samples that require hand polishing have been used to characterize the outcomes of new hardware innovation such as build control software powered by in-situ monitoring systems in LPBF AM systems. Figure 4 shows a complex geometry used during early stages of development of an in-situ energy input control software. Document plane of polish and in-process work. Keeping notes of AM density cubes in the as-received condition, and at each stage of grinding and polishing, including the finished plane of polish, will help build good in-house standard operating procedures and workflow optimization. Analyzing more than one plane of final polish on samples provides more certainty. Documenting each step in between records the state of large pores and whether enough material has been removed to polish through them by the final plane. After all, a density cube and its pores are three dimensional and metallographic inspection is a two-dimensional view. If complete documentation through different planes of the preparation procedure and more than one final plane of polish is examined, this provides a 2D+ analysis. While not a fully 3D analysis, metallography still provides a cheaper and more adaptive analysis technique (in terms of geometry) than computed tomography. The AM-focused metallographic laboratory is a combination of traditional metallographic knowledge and skill applied to analyses that provide insight into the optimization of the LPBF manufacturing process. Knowledge gained through metallography in AM laboratories has and will continue to advance additive manufacturing. ~AM&P For more information: Dana Drake, senior lab engineer-metals, EOS North America, 3813 Helios Way Suite 298 B, Pflugerville, TX 78660, dana.drake@ eos-na.com, www.eos.info. STAY AHEAD OF YOUR PROFESSIONAL JOURNEY WITH ASM EDUCATION & TRAINING. EARN CEUs, ENJOY DISCOUNTS, NETWORK, AND LEARN FROM INDUSTRY EXPERTS. SCAN TO ENROLL TODAY Education
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