21st century, materials, energy, information is the three cornerstones of modern industrial development, their level of development, on behalf of a country's overall scientific and technological development. In materials science, and double metal technology is a very important tool to increase the service life of mechanical parts, ordinary metal material as the parent composite another layer alloy has a special role in the mechanical parts of the work surface, with In order to improve the anti-wear, anti-corrosion performance of the parts and increase component life. To obtain the best value for money in the most economical material structure, bi-metal technology have become a driving force behind the sought-after in the world materials sector. As an emerging, with unparalleled development potential of the new technology, bi-metal technology in China's industrial development in all areas of showing an increasingly important role.

    With the rapid development of the plastics processing industry, a variety of new modified plastic materials continue to emerge. High strength reinforced plastic materials, it is often added, such as carbon, asbestos, glass, boron and other reinforcing fibers; addition, in order to reduce production costs in order to obtain a variety of special properties, or the purpose of a plastic resin, they often need to be added a certain proportion of various fillers, such as chalk, silica, heavy crystal white, clay, cellulose, mica, talc, alumina, and metal powder or the like. These reinforcing agents, fillers and inorganic colorant Add or recycled plastic or recycled sediment impurities are exacerbated by a plastic extruder machine, plastic injection machine cardiac member - melter cylinder and the corrosion of the conveyor screw or wear failure, so that the processing machinery production efficiency, product quality is unstable, the frequency of maintenance of machinery and replacement parts, increased costs, a great impact on the economic efficiency of enterprises of various plastic processing industry. Production situation is increasingly urgent appeal: instead of conventional nitriding treatment with high wear-resistant, corrosion-resistant bimetallic barrel and screw screw and barrel as the heart of the machine parts to extend the life of the machine.

    What is a bimetallic barrel? With different types of high wear resistance, high corrosion-resistant alloy composite materials as the working layer of the inner bore surface at a cylinder (or as sol cylinder). Alloy material thickness of 2.0 to 3.0 mm, the Rockwell hardness is generally 60 degrees or more, then after the special mechanical processing from the barrel, is a bimetallic barrel; Bimetallic screw is in its spiral rib lot work surface, or the entire spiral edge face, the thickness of the composite layer is generally 1.0 to 2.0 mm and special alloys (alloy Rockwell hardness is generally more than 58 degrees), from the processing of by special mechanical screw. Bimetallic barrel and bi-metal screw unique advantages than conventional nitriding screw barrel sales price is less than 1 times the theoretical service life for the ordinary nitriding screw barrel 4 times or more, the price is quite significant .