BIMETALLIC PLATE

摘要

Bimetallic plate is produced by providing a substrate (S) of a first metal and, with the preheated substrate (S) positioned in a mould cavity (34) with a major surface of the substrate (S) facing upwardly and to fill a portion of the depth of the cavity (34), a second metal is cast against that surface to form a cladding component and, with the substrate (S), to form the bimetallic plate. Prior to the cladding being cast, the major surface is rendered substantially oxide-free and is protected against oxidation. The cladding is cast by a melt, of a composition required for it, being poured at a superheated temperature whereby, with the preheating of the substrate (S), an overall heat energy balance is achieved between the substrate (S) and the cladding. The heat energy balance causes a diffusion bond to be achieved between the major surface of the substrate (S) and the cladding, and attainment of the energy balance is facilitated by causing the melt to enter the mould cavity (34) through a series of gates (44) which provide communication between at least one runner (40) and the mould cavity (34). The series of gates (44) is disposed laterally with respect to flow of the melt therethrough whereby the melt forms a laterally extending melt front. Attainment of the heat energy balance is further facilitated by causing the melt front to advance away from the gates (44), over the substrate (S) surface, at a rate which is substantially uniform across the lateral extent of the front.