DESIGN AND APPLICATIONS OF POWDER ATOMIZATION SYSTEM
AbstractIn this study, which have been made the design, manufacture and product production of the gas atomization unit. The Gas Atomization Unit consists of seven basic sections. These sections can be identified as; Melting furnace, Atomization tower, Nozzle, Powder collecting division, Cyclones and Gas pressure ramp and control panel. The melting furnace is designed to be capable of operating at temperatures up to approximately 1200 ℃. With the aim of prevent the oxidation of molten metal and produced powder, from the sides the of the melting furnace and from tower Argon gas is continuously being sprayed. The melting process is carried out in stainless steel melting pot according to the chemical composition of the material. Al12Si, AZ91, AM60 and AZ31 of the alloys powders were produced first with the gas atomization unit manufactured and designed. It was ascertained that the powders produced were between 0,1 microns and 750 micron and size of the 90 percent of the produced powders were below 100 microns. Experimental studies were carried out using different temperatures, different nozzle and different gas pressures. Argon gas was used to atomize the melt and frame a protective gas atmosphere. SEM-EDX analyzes were used to determine the phases of the internals of the produced powders and the percentage of these phases, and a laser measurement device was used for powder size analysis to determine the shape of powders. Microhardness measurements were also made to determine the hardness of the powders. Besides it was observed that size of powders was decreased depending on the increase of the gas pressure and changed their shapes from ligament to spheroidal. The fracture surface prior to sintering, where the amount of porosity in the specimens decreased and the volumes of the existing pores decreased with the increase of the pressing pressure, were determined from the SEM images. It has been determined that at low sintering temperatures, fracture occurs between intergranular cracks, while ductile fracture occurs as the sintering temperature increases.