Research status of dual liquid bimetallic composite casting technology for wear resistant castings

Bimetallic material is a new type of functional material composed of two metals with different mechanical, physical and chemical properties. Its composite interface presents a solid metallurgical bonding state. 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 anti-wear ability, initial impact resistance, corrosion resistance, etc. the combination of some hard and brittle materials and good plastic materials can overcome the deficiency of weak deformation ability. 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 composite casting method belongs to liquid-liquid composite method. It is widely used in the early washing casting composite milk auxiliary production. In recent years, this method has also achieved success in manufacturing wear-resistant castings, especially in the production of high chromium cast iron carbon steel bimetallic ball mill lining plate, crusher glume plate, plate hammer and fan grinding strike plate.

In this process, the winding and riser systems must be set for the two kinds of liquid metal. First, one metal is Rao in, and then another metal is wound after a suitable cooling time, so as to prepare a bimetallic casting taking into account the properties of the two materials. Among them, the horizontal and vertical winding compound method with intermediate diaphragm, the horizontal Rao injection compound method without diaphragm and the transformation mold compound method with double liquid winding are widely used in production.