Title:
【発明の名称】特殊金属の溶融および鋳込み
Document Type and Number:
Japanese Patent JP2002508496
Kind Code:
A
Abstract:
Specialty metals and alloys are melted in a crucible typically holding no more than about 100 lbs. of the metal and disposed in a furnace the interior of which is filled with a desired, e.g. inert, gas and subjected to a vacuum in the range of about 5% to 32% of atmospheric pressure. For special circumstances, it would be possible to start in the specified pressure range and then increase the melt chamber pressure to atmospheric or above. The vacuum permits the initiation and formation of long electric discharge arcs between the electrode of an immovable plasma torch mounted to the furnace and the inside of the crucible to provide enough space for charging of the crucible with fresh metal laterally through a charge opening in the upright side wall of the furnace and a vacuum chamber operatively connected with the charge opening. The melted metal is drained from the crucible through a drain hole in the bottom into molds which typically have close to the desired finished shape of the article and which can be removed from the furnace without the need to break the vacuum therein. A skull forming along the inside surfaces of the crucible is lifted off the crucible surfaces after each pour with a closure plate that is pushed from below into the drain hole. The skull is then melted with the plasma torch so that resulting melted metal collecting in the drain forms a drain plug upon solidification.
Inventors:
Haun, Robert E.
Lampson, Robin A.
Lampson, Robin A.
Application Number:
JP2000538822A
Publication Date:
March 19, 2002
Filing Date:
December 16, 1998
Export Citation:
Assignee:
Rockheed Martin Advanced Environmental Systems, Inc.
International Classes:
H05B7/20; B22D1/00; B22D27/02; B22D45/00; F27B3/08; F27B3/19; F27D3/14; F27D3/15; F27D11/08; F27D99/00; (IPC1-7): F27B3/08; B22D1/00; B22D45/00; F27B3/19; F27D3/14; H05B7/20
Attorney, Agent or Firm:
Shusaku Yamamoto