1 Department of Mechanical Engineering, Technical University of Denmark2 Manufacturing Engineering, Department of Mechanical Engineering, Technical University of Denmark3 FOSECO Sweden4 Vald. Birn A/S
In vertically parted molds it is traditionally difficult to feed heavy sections that cannot be reached by traditional side/top feeders or other conventional methods. This project aims at quantifying the effects of using molded-in ram-up spot feeders as a means of feeding isolated sections in castings made in vertically parted molds and it gives directions towards the effectiveness of this technology. The casting examined is a disc-shaped casting with an inner boss and an outer ring, separated by a thin walled section. Thus, both boss and ring are prone to porosities. The experimental work analyses the effect of different exothermic and insulating spot feeders and their interaction with traditional parting line feeders, with respect to porosities and surface shrinkage. Experiments were performed using EN-GJS-500-7 and EN-GJS-450-10 alloys. The experiment shows that the geometry cannot be cast successfully without the use of both a top and a spot feeder. Leaving out one or both feeders, results in porosities and surface shrinkage. For EN-GJS-500-7 any combination with both feeders present produced sound castings. For the more demanding EN-GJS-450-10 the exothermic spot feeder produced sound castings. All other combinations displayed some degree of porosities.