Single-handed spring actuated powder sampler for additive manufacturing

Abstract

Additive manufacturing (AM) is a rapidly expanding manufacturing technique due to its ability to produce complex-shaped parts on demand. Laser powder bed fusion (LPBF) is an additive manufacturing process that involves melting thin, ideally uniform, but not necessarily so, spread powder layers through selective laser or electron beam rastering. This process requires spreading high-quality powders, preferably those with a narrow size distribution and spherical morphology, to form a compact powder bed suitable for selective melting and the formation of high-density components. During the AM process, powder morphology and size may change due to agglomeration, partial sintering, spatter formation, and other defects; therefore, careful monitoring of these changes is essential to maintain suitable flowability and spreadability. Standard powder sampling devices, for example, as used in pharmaceutical and agricultural industries, are too large to extract AM samples without significant interlayer particle mixing. Therefore, a new compact, single-handedly actuated powder sampler was designed and fabricated for use within a selective laser melting printing chamber to sample AM powders at shallow depths. Samples can be analyzed for changes in size distribution, morphology, and composition (e.g., surface degradation) after each build.