초록 ▼

An improved magnesium die casting system incorporates filling of the shot sleeve from the underside and/or in-line re-melting of scrap magnesium using a re-melt furnace. A pump is used to transfer molten magnesium from a casting furnace to the shot sleeve through an underflow filling tube. The shot

An improved magnesium die casting system incorporates filling of the shot sleeve from the underside and/or in-line re-melting of scrap magnesium using a re-melt furnace. A pump is used to transfer molten magnesium from a casting furnace to the shot sleeve through an underflow filling tube. The shot sleeve is filled in a laminar manner, minimizing entrapped gases. The in-line re-melt system allows recycling of scrap in-house and reduces energy cost associated with heating and re-heating scrap. The improved system increases casting quality and reduces scrap rates and recycling costs.

대표청구항 ▼

1. A magnesium die casting system for in-line recycling of scrap magnesium, the system comprising a re-melt furnace in fluid communication with a casting furnace in fluid communication with a pump for supplying molten magnesium to a die casting machine that produces solid castings and solid scrap, t

1. A magnesium die casting system for in-line recycling of scrap magnesium, the system comprising a re-melt furnace in fluid communication with a casting furnace in fluid communication with a pump for supplying molten magnesium to a die casting machine that produces solid castings and solid scrap, the solid scrap re-introduced into the re-melt furnace, the re-melt furnace comprising a plurality of heating zones, each heating zone comprising a heat transfer material, and wherein a different heat transfer material is used in one or more zones.2. The magnesium die casting system of claim 1, wherein each heating zone includes one or more heating elements and wherein the heating elements are located adjacent the heat transfer material.3. A magnesium die casting system for in-line recycling of scrap magnesium, the system comprising a re-melt furnace in fluid communication with a casting furnace in fluid communication with a pump for supplying molten magnesium to a die casting machine that produces solid castings and solid scrap, the solid scrap re-introduced into the re-melt furnace, the re-melt furnace comprising a plurality of temperature sensors located at a plurality of positions within the furnace.4. The magnesium die casting system of claim 3, wherein the temperature sensors are located within different regions within the re-melt furnace.5. A magnesium die casting system that includes in-line recycling of scrap magnesium, the system comprising:a) a re-melt furnace, the re-melt furnace comprising a crucible containing molten magnesium stratified into three regions: an upper region; a lower region; and, a clean region between the upper and lower regions; b) a casting furnace in fluid communication with the re-melt furnace by siphoning through a U-shaped tube having an inlet located within the clean region and an outlet located within the casting furnace; c) a die casting machine comprising a shot sleeve and a die, the die casting machine for producing solid magnesium die castings and solid magnesium scrap; d) a pump located within the casting furnace for supplying molten magnesium directly to the shot sleeve of the die casting machine through a filling tube connected to the shot sleeve; and, e) means for re-introducing the solid magnesium scrap into the re-melt furnace that substantially prevents the ingress of air into the re-melt furnace. 6. The magnesium die casting system of claim 5, wherein the ratio of scrap material to virgin material in the furnace is from 15% to 45%.7. The magnesium die casting system of claim 5, wherein the magnesium die casting system comprises means for monitoring purity of the molten magnesium in the middle zone.8. The magnesium die casting system of claim 5, wherein the magnesium die casting system comprises means for continuously monitoring purity of the molten magnesium in the middle zone.9. The magnesium die casting system of claim 5, wherein the crucible is shaped to promote stratification of the molten magnesium into the at least three regions.10. The magnesium die casting system of claim 5, wherein the re-melt furnace includes a plurality of heating zones that may be independently controlled.11. The magnesium die casting system of claim 10, wherein each heating zone includes one or more heating elements that may be used to deliver different amounts of heat in each heating zone.12. The magnesium die casting system of claim 5, wherein the U-shaped tube comprises a filter for excluding impurities and/or sludge from casting furnace.13. The magnesium die casting system of claim 5, wherein the crucible includes one or more baffles.14. The magnesium die casting system of claim 13, wherein the baffle or baffles is/are removable.15. The magnesium die casting system of claim 5, wherein the means for re-introducing the scrap magnesium comprises an air-lock.16. The magnesium die casting system of claim 5, wherein the re-melt furnace includes means for withdrawal of impurities from the upper and lower regions.17. The magnesium die casting system of claim 5, wherein the re-melt furnace includes means for re-introduction of alloy constituents.18. The magnesium die casting system of claim 5, wherein the re-melt furnace comprises a temperature sensor located within each region of the re-melt furnace.19. The magnesium die casting system of claim 5, wherein re-melt furnace does not use flux.20. The magnesium die casting system of claim 5, wherein the filling tube is connected to an underside of the shot sleeve.