Industry News

Shenli main product swing chain,iron chain.

« Traditional industries to environmental protection to upgrade the War the South China Sea into a model underwearElectric kitchen cabinet hardware company collapsed superb after-sales is the key focus »

Hardware Knowledge Church: An Analysis of tool material and performance

    Cutting tool material is a fundamental factor in the decision tool, for processing efficiency, processing costs, processing quality, and tool life greatly.
    The use of carbon tool steel as the tool material, cutting speed 10m/min only about; and early 20th century, high-speed steel tool material, cutting speed up to tens of meters per minute; 30 years there carbide, cutting speed increased to every minutes more than 100 meters to hundreds of meters; current ceramic tool and the emergence of superhard cutting tool so that the cutting speed increased to more than 1000 meters per minute; is processed materials also greatly promoted the development of tool materials development.

    First, the performance of tool material should have.

    Excellent tool materials, tool to ensure the basic conditions for effective work. Cutting tool part in the strong friction, high pressure, high temperature work, should have the following basic requirements.

    High hardness and high wear resistance.

    The hardness of tool material must be higher than the hardness of the material can be processed cut metal, which is the basic requirements necessary tool material, tool material hardness are available for more than 60HRC. The more hard tool material, the better its wear resistance, but more complex cutting conditions, wear resistance also depends on its chemical composition and microstructure stability.

    Sufficient strength and toughness.

    Strength refers to the role of resistance to cutting forces they would not collapse broken blade and the arbor with the performance to be broken. Generally used to represent the bending strength.

    Toughness refers to the cutting tool material in the intermittent or the impact of working conditions to ensure no chipping capacity, in general, the higher the hardness, toughness, the lower, the more brittle material. Hardness and toughness is a contradiction, is also the tool material should overcome a key.

    High heat resistance.

    Heat resistance, also known as red hardness is a measure of tool material properties of the key indicators. Which reflects the tool material at high temperature to maintain the hardness, wear resistance, strength, anti-oxidation, anti-adhesion and anti-proliferation capabilities.

    Good technology and economy.

    In order to facilitate manufacturing, tool material should have good manufacturability, such as forging, heat treatment and grinding performance. Of course, in the manufacture and use should be taken into account economy. Current super-hard cutting tool materials and coating materials costs are more expensive, but life is very long, in the bulk mass production, the share of each part of the cost was decreased. Therefore, the choice must be taken into account when.
     Second, common tool materials.

    Common tool materials are tool steel, high speed steel, carbide, ceramics and superhard cutting tool materials, currently used for most high-speed steel and carbide.

    High-speed steel.

    High-speed steel is a more joined tungsten, chromium, vanadium, equal to the high alloying elements of alloy tool steel, has a good overall performance. The strength and toughness is the highest existing tool material. High-speed steel manufacturing process is simple and easy grinding into a sharp cutting edge; forging, heat distortion, present in the complex tools, such as twist drills, taps, broaches, gear shaping tool and tool manufacturing, still occupies the main position.

    High-speed steel can be divided into ordinary high speed steel and high-performance high-speed steel.

    Ordinary high speed steel, such as W18Cr4V widely used in the manufacture complex cutting tools. swing chain The cutting speed is generally not too high, cutting ordinary steel materials when 40-60m/min.

    High speed steel, such as W12Cr4V4Mo is common in some additional high-speed steel carbon content, vanadium content and added cobalt, aluminum smelting and other elements formed. Its durability is 1.5-3 times that of ordinary high speed steel.

    Powder Metallurgy High Speed Steel is the 70's the market of a high-speed steel, iron chain its strength and toughness were increased by 30% -40% and 80% -90%. Durability can be increased 2-3 times. At present, China is still in the pilot study stage, production and use is still low.

    Carbide.

    According to GB2075-87 (reference by 190 standards) can be divided into P, M, K categories, P type carbide is mainly used for processing chip long black metal, with blue as an indicator; M class is mainly used for processing of ferrous metals and non-ferrous metals, with the yellow flag, also known as Universal Carbide, K class is mainly used for processing short chip of ferrous metals, nonferrous metals and non-metallic materials, with red as an indicator.

    P, M, K (behind the Arabic numerals that their performance and processing load to bear the situation or processing conditions. Lower the number, the higher the hardness, toughness worse.

    P class equivalent to our original tungsten titanium drill class, mainly composed of WC + TiC + Co, code-named YT.

    K class equivalent to our original tungsten drill class, mainly composed of WC + Co, code-named YG.

    M class equivalent to our original class of general-purpose tungsten cobalt alloy titanium tantalum, mainly composed of WC + TiC + TaC (NbC) + Co, code-named YW.
    3, coated tools briefly.

    Coated tools are the last 20 years the emergence of a new cutting tool material, tool development is an important breakthrough in solving the cutting tool material hardness, wear resistance and strength, toughness contradiction between an effective measure. Coated tools is better in some tough carbide or high speed steel tool substrate, coating a layer of hard wear high melting metal compounds obtained. Commonly used coating materials are TiC, TiN and Al2O3, etc.. The early 70s for the first time this century in the cemented carbide substrate coated with a layer of titanium carbide (TiC), put the ordinary carbide cutting speed increased from 80m/min to 180m/min. Emerged in 1976, titanium carbide - aluminum dual-coated cemented carbide, the cutting speed up to 250m/min. In 1981 appeared the titanium carbide - aluminum - cobalt III nitride coated carbide, so that the cutting speed up to 300m/min.

    In the high-speed tool steel substrate coated mostly TiN, used physical vapor deposition (PVD method) coating, generally used for drill bits, taps, milling cutters, hobs and other complex tools, the coating thickness of several microns, coating Hardness up to 80HRC, the equivalent of a general carbide hardness, durability can be increased 2-5 times, cutting speed can be increased by 20% -40%.

    Carbide coating is the toughness of the cemented carbide substrate, coated with a layer of several microns to ten microns thick, high wear and difficult to melt the metal compounds, usually by chemical vapor deposition (CVD method) . Production plants in China Zhuzhou Cemented Carbide coated carbide coating thickness up to 9μm, surface hardness up to 2500-4200HV.

    At present the industrial countries of the coated tools of research and promote the use of develop very rapidly. Leading Sweden, in turning using coated carbide inserts have accounted for 70% -80% in milling has reached 50%. But not suitable for machining high temperature alloy coated tools, titanium and non-metallic materials, also are not suitable for rough gravel, the malleable pieces of crust.

    4, diamond cutting tools.

    Divided into natural diamond and diamond tools synthetic diamond tools. Natural diamond has the highest natural material hardness and thermal conductivity c but expensive, processing, welding is very difficult, except for a few special purpose (such as watches, precision components, optical accessories and jewelry engraving and other processing), and few are cutting tools used in industry. With the high-tech and ultra-precision machining growing. Such as micro-mechanical micro-parts, atomic reactors and other high-tech fields of various mirrors, missile or rocket in the top navigation, the computer hard drive chips, accelerator electron gun, such as ultra precision machining, a large natural single crystal diamond to meet these requirements . In recent years developed a variety of chemical methods of diamond tools grinding mechanism and protection of the atmosphere brazing diamond. Make natural diamond tool manufacturing process becomes more simple. Thus, in ultra-precision mirror surface machining of high-tech applications. Played an important role in natural diamond.

    50 years of the 20th century using high pressure technology of synthetic diamond powder after 70 years to create the diamond-based polycrystalline diamond cutting tool (PCD). Xu Xu grain PCD was no arrangement of the state. Non-directional, and therefore uniform hardness. It has high hardness and thermal conductivity, low thermal expansion coefficient. High modulus and low coefficient of friction, the blade is very sharp. It can be very resistant gading various non-ferrous metals and high-performance non-metallic materials such as aluminum, copper, magnesium and its alloys, carbide, fibers plasticized materials, metal matrix composites, wood composite materials.

    Three major diamond cutting tool material - PCD, CVD Thick Film and synthetic single crystal diamond and their performance was characterized by: PCD welding, mechanical grinding and the highest fracture toughness, wear resistance and edge quality center, corrosion resistance worst. CVD thick film the best corrosion resistance, mechanical grinding of, edge quality, and fracture toughness and wear resistance of the middle, poor welding, synthetic single crystal diamond cutting edge quality, corrosion resistance, abrasion resistance and the best welding , mechanical grinding and fracture toughness of the worst.

    Diamond tool is the high-speed cutting (2500 ~ 5000m/min) aluminum ideal tool material, but because of carbon's affinity for iron, especially at high temperatures, diamond can react chemically with the iron, so it should not be on the cutting iron and alloy parts.

    5, cubic boron nitride.

    Cubic boron nitride (CBN) is a pure synthetic material. It is the late 20th century 50 diamond with a similar method of manufacturing the second superhard materials synthesis - CBN powder. As the poor performance of CBN sintered until the 70's was made of cubic boron nitride agglomerate (polycrystalline cubic boron nitride, PCBN), it is by the CBN powder and a small amount of binder phase (Co, Ni or TiN, TiC, or Al2O3 ) sintered at high temperature and pressure. CBN is a dense phase of BN has a high hardness (second only to diamond), and heat resistance (1300,1500 degrees), good chemical stability in parts (much better than diamonds) and thermal conductivity, low coefficient of friction . PCBN and low affinity Fe group elements, it is the ideal high-speed cutting tool ferrous metal materials.

Post comment:

◎welcome to give out your point。

Calendar

Comments

Previous

Zhejiang Pujiang Shenli Chain Co.,Ltd.Professionally manufacture swing chain,iron chain.