Main casting methods of bimetallic composite lining plate

Bimetallic composite technology is becoming more and more widely used in the manufacture of wear-resistant materials. The fundamental reason lies in the high hardness and low toughness of materials with high wear resistance. If the non wear parts of components can be replaced with ordinary materials with high toughness, it can not only maintain high wear resistance in the working part, but also ensure that the components have high impact resistance. Recently, the price of alloy has risen sharply. Composite casting is also conducive to saving expensive alloy materials, which is of practical significance for the popularization and application of high wear-resistant materials (high chromium cast iron, high vanadium high-speed steel, etc.).

Therefore, alloy white cast iron with excellent wear resistance is combined with low-carbon steel with certain strength and toughness. White cast iron can effectively resist abrasive wear as an anti-wear component, while low-carbon steel has certain strength and impact toughness to withstand impact load. This kind of composite metal material has a broad application prospect under the working conditions of severe abrasive wear and large impact load.

Bimetallic composite lining plate mainly has the following casting methods:

1) Double liquid composite casting

It has the characteristics of good interface combination, but the process operation requirements are strict. Generally, it can only be used for composite plate parts and ring parts. A clapboard is added between the two layers of metal. The two metals are injected into the mold cavity at the same time by two sets of gating systems. The two layers of metal are fused and combined with each other through the intermediate transition layer to form a complex. Its production technology is becoming more and more mature.

2) Liquid solid composite casting

Composite process of high chromium cast iron and medium carbon steel. The surface of medium carbon steel is polished to remove the surface oxide film and reduce the surface tension of liquid metal. At the same time, a layer of borax is coated on the surface to increase its wettability with pouring liquid high chromium cast iron. High chromium cast iron melt is closely combined with medium carbon steel by liquid-solid combination to form a complete casting.

3) Inlay casting

It is a kind of liquid-solid compound method, which generally refers to the hard blocks with high hardness and high wear resistance (such as cemented carbide, ceramic blocks, etc.) embedded in the wear-resistant parts of wear-resistant castings by casting method. In recent years, metal / ceramic composites are a research hotspot, and some research results have been applied.