The physical and mechanical properties of bimetallic composites are different. Although the two metals maintain their original characteristics, their comprehensive physical, chemical and mechanical properties are much superior to those of a single metal. With appropriate metal materials and composite molding process, the service performance of metal materials can be greatly optimized, such as wear resistance, initial impact resistance, corrosion resistance, etc. by combining some hard and brittle materials with materials with good toughness, the deficiency of weak deformation ability can be overcome.
At present, the forming methods of bimetallic composites mainly include: composite casting, diffusion bonding, rolling composite, extrusion molding, chemical coating, powder metallurgy and so on. Among them, cast composites have the advantages of firm interface bonding, simple process, high production efficiency and low manufacturing cost, and their application has been greatly developed. According to the physical state of metal in composite casting, it can be divided into liquid-solid composite and liquid-liquid composite.
Bimetallic liquid compound casting method belongs to liquid-liquid compound method. It is widely used in the early production of flushing casting composite roll. In recent years, this method has also achieved success in manufacturing wear-resistant castings, especially in the production of high chromium cast iron
Satisfactory results have been obtained in terms of carbon steel bimetallic ball mill lining plate, crusher jaw plate, plate hammer and fan mill striking plate.
In this process, it is necessary to set respective pouring and riser systems for two kinds of liquid metal. First, one metal is spared, and then another metal is poured after appropriate cooling time, so as to prepare bimetallic castings taking into account the properties of two materials. Among them, the middle diaphragm / horizontal vertical pouring compound method, double liquid horizontal pouring compound method without diaphragm and double liquid pouring / transformation mold compound method are widely used in production.