Theoretical and experimental investigation of mold strength in magnetic molding compacts

Magnetic molding process is an economic and environmentally friendly casting technique. In this process, steel shots of size varying from 0.2 to 0.6 mm diameter is packed around an expendable pattern. The steel used in the steel shots has 0.8 wt.% carbon content and has minimum amount of non-metallic inclusions and impurities. It is the grade widely used in conventional shot blasting process. When magnetic field is applied on the shots they are consolidated around the pattern. Molten metal may then be poured over the pattern when the shots backup. In our present work, strength of the mold has been found by theoretical and experimental methods. The pattern of arrangement of the balls in the packing has been experimentally determined in order to aid the theoretical analysis. Mold strength trials have been conducted using 0.4 and 0.6 mm steel shots under different positions at various magnetic fields. The theoretical and the experimental values show varying degrees of correlation. The conditions for the maximum strength of the mold and correlation between the theoretical and the experimental values have been determined thus.