Shielding gas, metal vapors, and gases trapped inside powders during atomization can result in gas porosity, which is known to degrade the fatigue strength and tensile properties of components made by laser powder bed fusion additive manufacturing. Post-processing and trial-and-error adjustment of processing conditions to reduce porosity are time-consuming and expensive. Here, we combined mechanistic modeling and experimental data analysis and proposed an easy-to-use, verifiable, dimensionless gas porosity index to mitigate pore formation.
View Article and Find Full Text PDFThis paper reports synthesis of a bioreducible hyperbranched (HB) polymer by A+B approach from commercially available dithiothreitol (DTT) (A) and an easily accessible trifunctional monomer (B) containing three reactive pyridyl-disulfide groups. Highly efficient thiol-activated disulfide exchange reaction leads to the formation of the HB polymer ( = 21000; = 2.3) with bioreducible disulfide linkages in the backbone and two different functional groups, namely, hydroxyl and pyridyl-disulfide in the core and periphery, respectively, of the HB-polymer.
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