USE OF SURFACTANTS ADDED TO REFRACTORY SLURRY IN PRECISION FOUNDRY AND INVESTMENT CASTINGS WITH ALUMINUM
Abstract:
<p align="justify"> The investment casting process, involving wax models invested with clays to give ceramic molds from which metal castings are made, is characterized by the obtainment of parts of high metallurgic quality, especially as far as dimensional aspects the complexity of design and surface finishings are concerned. The high-precision parts have a wide application in the electronic, aeronautical, biomedical, textile, and food industries. Twenty-one different surfactants, added to refractive zirconite slurry, were tested for their efficiency in obtaining wetting and adherence to the surface of the wax and good quality finished aluminum parts. Only five surfactants, including sodium dodecylbenzene sulfonate, sulfonic acid, dioctyl sodium sulfosuccinate, and ethoxylated long-chain alcohols, gave satisfactory results. Analysis of the specimens manufactured from 98% aluminum, poured at 710 °C, by visual observation, rugosity, optical photography, and electron microscopy showed that they were of high quality. The present paper describes the results obtained with sulfonic acid C <sub>8-l6</sub> and sodium dodecylbenzene sulfonate and explains the effect of the surfactants by the formation of a monolayer film or hemi-micelles between the wax and the ceramic slurry. </p>
<p align="justify"> The investment casting process, involving wax models invested with clays to give ceramic molds from which metal castings are made, is characterized by the obtainment of parts of high metallurgic quality, especially as far as dimensional aspects the complexity of design and surface finishings are concerned. The high-precision parts have a wide application in the electronic, aeronautical, biomedical, textile, and food industries. Twenty-one different surfactants, added to refractive zirconite slurry, were tested for their efficiency in obtaining wetting and adherence to the surface of the wax and good quality finished aluminum parts. Only five surfactants, including sodium dodecylbenzene sulfonate, sulfonic acid, dioctyl sodium sulfosuccinate, and ethoxylated long-chain alcohols, gave satisfactory results. Analysis of the specimens manufactured from 98% aluminum, poured at 710 °C, by visual observation, rugosity, optical photography, and electron microscopy showed that they were of high quality. The present paper describes the results obtained with sulfonic acid C <sub>8-l6</sub> and sodium dodecylbenzene sulfonate and explains the effect of the surfactants by the formation of a monolayer film or hemi-micelles between the wax and the ceramic slurry. </p>
DOI: 10.48141/SBJCHEM.v2.n2.1994.43_1994.pdf
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