Investigation of the effect of grain refinement and solidification under mechanical vibration on casting properties of etial 177 aluminum alloys in sand and plaster mold casting

In this study, the effect of grain refiner addition and solidification under mechanical vibration on casting and mechanical properties of Etial 177 aluminum alloy in sand and gypsum mold casting was investigated. In this way, the results obtained from castings and mechanical properties of Etial 177 aluminum alloys have been revealed by experimental studies. Etial 177 aluminum alloy was melted at approximately 750°C, and the casting of the designed model was carried out in sand and plaster molds without additives and with the addition of grain refiner. The liquid metal used in the castings was first washed with nitrogen, and then a reduced pressure test was carried out to test the gaseous state. The archimedean density test was applied by cutting the models in different sections, and then samples were taken from the model in different thicknesses and microstructure studies were carried out by applying metallographic sample preparation processes. For each casting method, tensile test was carried out by casting the tensile rods in standard sizes designed into the mold and by processing the tensile rods at standard intervals. Finally, the hardness measurement test was applied to the sections taken from the cast models. As a result, after the casting of Etial 177 aluminum alloys, the results were obtained that the mechanical vibration has a positive effect on the internal structure, the pore value of the castings with grain refiner is further reduced compared to the castings, and the dendrites formed with the increase in the grain size with the increase in the casting section thickness become more coarse with the cooling rate. The hardness values obtained from the experiments were between 50.12 HBN and 62.34 HBN, and the highest hardness value was measured as 59.28 HBN under vibration solidification conditions with the addition of TiB to the sand mold. When the tensile test results were examined, the highest tensile strength was measured as 210.14 MPa in the grain thinner added, solidified under vibration, sand molded samples.