Fundamentals of the New Rheocasting Process for Magnesium Alloys

Casting of high strength, ductile and pressure tight components at low cost is the prerequisite for the introduction of magnesium alloys into hydraulic and structural applications. This paper introduces the New Rheocasting process (NRC) as a novel approach for semi-solid casting of light metals, in which the slurry is prepared from normal casting alloys directly at the foundry machine. The specialties of the process and the alloy requirements are explained. Ways for increasing ductility and process stability with slight alloy modifications and proper heat treatment are shown. The resulting mechanical properties are compared with data received from classical high pressure die casting parts. New Rheocasting of the alloy AZ71proves to be superior in strength and ductility, and shows excellent KJC values.