Search

Additive manufacturing offers great potential for various industrial solutions; in particular, the binder jetting method enables the production of components from various materials, including sand molds for casting. This work presents the results of an extensive set of experiments aimed at enhancing the structural strengthening of 3D-printed sand molds. Structural strengthening was achieved by impregnating the sand-printed structures with two polymer materials: epoxy resin and silicone varnish. Impregnation was performed with variable parameters, such as temperature, pressure, and time. Structural strengthening using polymers was investigated by analyzing the flexural strength and impact resistance of the impregnated products and comparing these obtained values with the reference material in terms of impregnation parameters and the polymer used. Microstructural observations and an analysis of the pore filling were also performed. This approach allowed for a full assessment of the influence of processing parameters and the type of polymer used for impregnation on the properties of sand-printed structures, which allowed for identifying the most optimal method to be used to strengthen the sand molds for casting the components for electrical devices. As a direct proof of concept, it was shown that impregnation with polymeric materials could effectively strengthen the sand mold, increasing its flexural strength and impact resistance by over 20 times and 5 times, respectively. A full-scale mold was printed using binder jetting, impregnated with epoxy resin at 65 °C, and used to successfully fabricate a fully functional electrification device. [ABSTRACT FROM AUTHOR]

This article presents a comparative analysis of the crucial physical properties of electrically conductive components made of pure copper, produced by various additive manufacturing technologies such as binder jetting (BJ) and direct metal laser sintering (DMLS). The comparison concerned the assessment of critical parameters important from the application point of view, such as: electrical conductivity, hardness, yield point, microstructure and the occurrence of internal material defects. Same-sized components made in a conventional casting and subtractive method (machining) were used as a reference material. Comprehensive tests and the comparison of a wide range of parameters allowed us to determine that among the selected methods, printing using the DMLS technique allowed for obtaining arcing contact with mechanical and electrical parameters very similar to the reference element. Therefore, the obtained results showed the possibility of using the copper elements made by additive manufacturing for the switching and protection devices used in electrification and energy distribution industrial sectors. [ABSTRACT FROM AUTHOR]

Material used as an electrical insulation has to combine many features, mainly dielectric, mechanical, and thermal parameters should be preserved. Appropriately selected polymer matrix and a suitable filler allow to obtain a multifunctional material for electrical devices. In the presented work, different types of commercial aluminosilicate fillers were used in order to obtain electrical insulation with enhanced properties in relation to reference silica‐epoxy resin composite. Thermal conductivity, mechanical parameters, dielectric properties and structure‐properties relationship were studied in order to examine the influence of size, amount and type of silanization of the filler. Composites filled with aluminosilicates exhibit much better mechanical properties as well as enhanced dielectric properties with 61% relative increase of thermal conductivity when they were compared with silica‐epoxy resin sample. The obtained results indicate that aluminosilicates are very attractive fillers for epoxy‐based composites used as an electrical insulation in power devices. POLYM. COMPOS., 40:3182–3188, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]