The emergence of new special ceramic tool materials is the first time that humans have revolutionized the mechanical cutting process by using inorganic ceramic materials. About a hundred years ago, in Europe, Germany and the United Kingdom, they began to seek to replace traditional carbon steel tools with ceramic tools. Special ceramic materials have become a new generation of tool materials due to their high hardness and high temperature resistance. However, ceramics are also limited by their well-known brittleness. Therefore, how to overcome the brittleness of ceramic tool materials and improve its toughness has become a hundred years. The main topic of ceramic tool research. The range of applications for ceramics is also growing. The main reasons for the engineering and technical community to develop and promote ceramic knives: (1) can greatly improve the production efficiency of metal cutting and processing (2) Considering the precious resources on the earth This is due to the global depletion of tungsten resources, which constitute the main component of high-speed steel and cemented carbide. According to preliminary estimates from relevant parties in the geological department in recent years, the proven tungsten resources in the world are only enough for 50 years. Tungsten is the most scarce resource in the world, but its consumption in cutting tool materials is very large, which leads to the rising price of tungsten ore, which has risen many times in several decades. This has also promoted the development of ceramic tools to a certain extent. Promotion, the development of ceramic tool materials has achieved remarkable results. The materials currently used as special ceramic knives have formed alumina ceramics, alumina-metal ceramics, alumina-carbide ceramics, alumina-carbide cermets, alumina-nitride cermets and the latest research successful nitriding. Boron ceramics, and silicon nitride ceramic tools and other materials. However, as far as the world is concerned, German ceramic tools have not only been used in ordinary machine tools, but have been used as an efficient and stable tool for digital control machine tool processing and automated production lines; Japanese ceramic blades in product types, output and quality The company has an international advanced level; the United States has always been a world leader in the development of oxide-carbide-nitride ceramic tools. At the same time, the research, development, and application of special ceramic tool materials in China are also achieving many results. Next page Glass Jug,Glass Teapot,Glass Pan Door Hardware Co., Ltd. , http://www.nsdhardware.com
1. Alumina ceramic knives: In special ceramic materials, the use of pure Al2O3 and other additives is beneficial to strengthen the flexural strength of Al2O3, but the high temperature performance is reduced, so it is better to use pure alumina ceramic materials. Al2O3 ceramics have higher room temperature hardness and high temperature hardness than cemented carbide materials. Although the flexural strength of Al2O3 ceramics is low at room temperature, its flexural strength decreases less as the temperature rises during use. It is quite suitable for high speed cutting based on this characteristic. Al2O3 ceramics have good compressive strength at room temperature and high temperature, and can overcome the disadvantages of deformation and collapse of the high-speed steel cutter and carbide cutting blade. In addition, Al2O3 ceramics can be used in physical thermal properties and resistance to oxidation, adhesion and chemical inertness. However, alumina ceramic cutters are more prone to bond wear and notch wear when cutting iron alloys and steel parts. As the longest used tool material, alumina ceramic tools are ideal for cutting hard and brittle metal materials such as chilled cast iron or hardened steel at high speeds; for cutting large parts and for cutting high precision parts. machining. Alumina ceramic cutters are inferior in short-cutting, small-part, intermittent cutting of steel and single-material materials such as Mg, Al, Ti and Be, and their alloy materials. It is easy to cause diffusion wear or spalling and chipping of the tool. Such defects, it is clear that this is a shortcoming of its inadequacy.
2. Alumina-metal ceramics: In order to improve the toughness of Al2O3 ceramic tools, less than 10% of metal elements such as Cr, CO, MO, W, Ti, Fe are introduced into the material, thereby forming Al2O3 cermet, so that the material density and resistance Strong bending strength and hardness are improved. However, due to the low creep strength of the alumina-cermet tool, the oxidation resistance is poor, and the promotion is not good.