PRODUCTION OF AL ALLOY CASTING

摘要

PURPOSE:To obtain a casting having excellent strength and toughness by adding a mixture composed essentially of specific components to a molten metal after charging of said metal to a casting mold or mold hopper until the solidification of the molten metal is completed. CONSTITUTION:A vacuum-packed Al can contg. metallic Na is disposed in the intermediate part 7 and/or lower part 8 of a riser part 5 prior to starting of pouring. The molten Al alloy which is melted and degassed and is added with the Na component so as to be improved in a melting furnace is poured from a crucible 9 into the pouring port 10 of the casting mold 1. The Al can is melted by contacting with the molten metal and the metallic Na incorporated in the Al can is melted into the molten metal. As a result, the amt. of the Na metal in the molten metal near the riser part 5 is increased amd the Na metal is diffused, by which the content of Na over the entire part of the molten metal is increased. The decrease in the Na during pouring is thus made up and the formation of the finer eutectic structure in the final casting is made possible.