It is well known that silicon improves the form-filling and deoxidation of castings. Up until now, it has been believed that silicon alone, and its reaction with oxygen and the formation of silica, could explain this improvement. This could be only partially true. Investigations suggest that silicon forms a high surface-tension compound in the molten alloy and, therefore, lets the liquid metal flow more easily, improving mold filling. This work aims to clarify the real mechanism of silicon's effect in investment casting of gold alloys. It will also study the possibilities of obtaining a partial or total alternative to silicon.

Author(s): Daniele Maggian, Paolo Baretta, Silvano Bortolamei, Iader Milani,  Alessandro Zocca