Investigation of the effects of printing parameters on the mechanical properties of sand casting molds produced by additive manufacturing method

Today, in the traditional casting method used in the casting industry, firstly model production, mold production from the model, then casting parts are produced by pouring the molten material into the cavity in the sand mold and solidifying. However, it is difficult to manufacture complex or hollow parts with this method. On the other hand, high model costs increase the initial investment costs. For this reason, the use of a 3D printer, which makes it possible to produce molds and cores directly without the need for a model, and by casting even hollow parts with complex geometries, gains importance. In this study, a binder jetting 3D printer design with a new nozzle system developed as an alternative to the spraying with cartridge method has been produced. 3D printer; It consists of 3 parts, the main chassis, the sand spreader and the spraying. Consumables used in sand mold production are silica sand, furan resin and catalyst. Sand molds were printed with different printing parameters (printhead feed rate, catalyst ratio, sand grain size) in order to produce cheaper, precise and high quality casting parts on the 3D printer. Finally, porosity, compression, bending, dimensional accuracy, gas permeability, loss on ignition test and SEM analysis of the molds printed on the 3D printer were performed and the effects of different printing parameters on these properties were examined. In addition, real size sand molds were modeled and hydrostatic pressure analysis was performed in Ansys program, and the results were examined. According to the test results, the compressive strength of the the samples was found in the range of 0,0472 MPa-0,6471 MPa, the gas permeability was found in the range of 150 GP-180 GP, the porosity ratio was found in the range of %38,69-%56,65, the flexural strength was in the range of 0,0301 MPa-0,3844 MPa, the loss on ignition rate was in the range of %3,06-%7,39 for the samples produced. As a result of the study, it was seen that the produced parts had sufficient mechanical properties to be used as sand molds. This printer has very low initial investment and consumable costs compared to existing commercial printers. With this study, steps were taken for domestic production with the successful production of this printer, which is thought to be useful in the production of sand molds required for casting special design or prototype products in the casting industry.