Performance and application range of the hottest h

Performance and application range of high-speed cutting tool material

from the study of high-speed cutting mechanism, we can see that with the increase of cutting speed, the metal removal rate has been greatly improved, and the high strain rate of the material (at the cutting speed of 500m/at high temperature, various adhesives can still be used for bonding, min is about 1.67 × 105/s, and the cutting temperature reaches 1400 ℃. The chip forming process and various phenomena on the contact surface between the tool and the workpiece are different from those under traditional cutting conditions. The thermal hardness and tool wear of tools become the key. In order to realize high-speed cutting, there must be tool materials and tool manufacturing technology suitable for high-speed cutting

there are nine kinds of metal cutting tool materials used now, including high-speed steel with the lowest cutting speed and the worst wear resistance to polycrystalline diamond tools with the best high-speed performance. High speed cutting also requires tool materials with good toughness, impact resistance and wear resistance

generally speaking, tools with low performance, such as high-speed steel and uncoated cemented carbide, are widely used in ordinary cutting, but their high-speed performance is not good. High performance tools, such as polycrystalline diamond tools, are the hardest of all tool materials, with very high wear resistance and speed ability. Cutting heat has little impact on them, which fully reflects its advantages in high-speed machining of non-ferrous and non-metallic materials. But its impact resistance is poor, and its thermal performance in cutting steel and cast iron materials is very poor. Because when cutting ferrous metals at high speed, the carbon atoms in the tool material will diffuse to the workpiece, resulting in increased tool wear

cemented carbide tools have the largest application, accounting for 80% of the total sales of various tools. 90% of metal cutting at ordinary speed adopts cemented carbide tools, and the measuring range of experimental force is 4% - 100% (equivalent to 3 gears). Cemented carbide has good impact toughness, but its high-speed performance is not good. In addition, high-speed cutting tools also have high thermal hardness and chemical stability, and cemented carbide can not meet the requirements in this regard

cb through repeated loading on different curve segments, n tool has excellent heat resistance and can cut hard materials at high temperature, but it is expensive and cannot process soft metal materials. Aluminum based ceramic materials with good chemical stability are just suitable for this kind of processing, but they lack thermal hardness and cannot be used for high-speed processing

it is one of the main problems to be solved in the research of high-speed cutting tools to concentrate the advantages of tool materials with different characteristics and develop new tool materials to make them have impact toughness and high wear resistance at the same time. On the tool base material with better impact toughness, the surface coating with materials with good thermal hardness and wear resistance to produce new tools often has the advantages of two materials. This kind of tools has a great range of application in high-speed cutting

under the guidance of this idea, new composite tools such as cemented carbide coated tools, CBN coated tools and PCD coated tools have appeared successively, which are suitable for high-speed cutting of different metal materials

coated cemented carbide tools suitable for high-speed cutting. Due to the use of coating materials with good heat resistance and high hardness and multi-layer coating technology, coated cemented carbide tools have a wide cutting range and long service life, and their cutting performance is much better than uncoated cemented carbide. Therefore, coated cemented carbide has a great tendency to replace ordinary uncoated cemented carbide

tool coating technology can be used not only on hardened alloy tools, but also on other tool materials, such as cermet, ceramics, etc

ceramic tools are also tools that can be used for high-speed cutting, and are an important part of the research and development of tool materials in recent years. Whisker reinforced ceramic tool is a kind of tool made of special materials. Because of its good impact toughness and strong thermal shock resistance, it is very suitable for high-speed machining

high speed cutting tools should have excellent impact toughness and thermal shock resistance, better heat resistance, wear resistance and chemical stability, as well as better chip breaking effect, and be suitable for larger gold. The experiment carried out by grinding one steel ball with three steel balls belongs to the cutting range. (end)