EPS bead fusion effects on fold defect formation in lost foam casting of aluminum alloys

The effects of bead fusion in the polymer pattern on fold defect formation in castings produced by the lost foam process have been investigated. Castings of aluminum alloy 319.1 were produced with commercial patterns that were molded with varying levels of bead fusion. Each casting was broken into over 40 pieces to identify the fold defect on the fracture surface. The results indicate that castings produced with patterns with high bead fusion exhibit a greater number and a larger area of folds than parts obtained by using foams with low bead fusion.