The quality of semi-products of platinum metals and alloys,produced by way of plastic working,essentially depends on or,in many cases,is completely determined by the quality of ingots.Plastic working does not make it possible to eliminate or localize metallurgical defects.In many cases it promotes the occurence thereof.Low-rate casting with directional crystallization can ensure the production of dense ingots free of non-metallic inclusions,shrinkage and gas weakness,with observance of certain temperature/rate modes.After comparative tests of vertical and horizontal molds,preference has been given to horizontal water-cooled molds,allowing to cast all alloys in the conditions of directional crystallization.
展开▼
