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Formstoffe und Formstoffprüfung
Dokumenten-Nummer: 57707
Zeitschriftenaufsatz
Ramrattan, Sam N.; Makino, Hiroyasu; Hirata, Minoru
Publikationssprache: Englisch
A study of erosion in aeration green sand molds with various alloys
Eine Studie über die Erosion in belüfteten Nassgussformen bei verschiedenen Legierungen
Erosive flow of molten metal in this casting trial compared the abrasion resistance of green sand molding techniques.
The aeration filled molds have shown to have less erosion tendencies than that of gravity filled molding methods. In this
experiment the factors that contributed to green sand erosion losses were lower squeeze pressure and increased
head-height. These results verify the earlier findings using laboratory tests. Friability is reduced with aeration. AFS green
sand friability testing measures the surface brittleness of a sample. Friable sand is one which is unable to withstand the
erosive flow of the molten metal. Molding sands can become very friable if there is too high an influx of core sand or
new sand and bond. Newbond requires several passes through the muller before its properties are developed. Friability
is inversely related to compactability. Lower the compactability, the higher the friability. A small drop in compactability,
or a brief air drying period, will produce a large increase in friability. There is published research that shows aerated
green sand molds can be produced at low compactability levels (