Rotary magnetic stirrer for continuous metal castings

ROTARY MAGNETIC STIRRER FOR CONTINUOUS METAL CASTINGS (M.Sc. Thesis) Osman GÜRDAL GAZI UNIVERSITY INSTITUTE OF SCIENCE AND TECHNOLOGY March 1991 ABSTRACT It is known that some of metallurgical defects occur during the solidification of molten metals. These are namely non equiaxed soli dification stuructures, the remains of pinholes, entrapments of slag patches and segregation of non metal particles on the centerline. Du ring the solidification of molten metals, these defects can be reduced by stirring the molten metal around mold with a rotary magnetic fi eld. In this study, an inverter (power source) and a stator for provi ding a magnetic field were designed and a prototype was constructed. In a M.Sc. Thesis, "Effects of Electromagnetic Stiring On Grain Size of Commercially Pure Aluminium", done with the prototype at the M.E.T.U., Metallurgical Engineering Department in September 1990, big reduction (95 %) of ratio of grain size were observed. The Grain size of free solidifiation of aluminium metal is 3.71 mm and 0.18 mm in stirred solidification. Ill