magnesium is magnesium-based alloy by adding other elements. Its characteristics are: low density (1.8g/cm3 magnesium alloy or so), high specific strength, elastic modulus, good heat dissipation, eliminating shock resistance, ability to withstand impact loads than aluminum, resistance to alkali corrosion of organic matter and good . Main alloying elements of aluminum, zinc, manganese, cerium, thorium and zirconium or a small amount of cadmium. Currently the most widely used is magnesium alloy, followed by magnesium and magnesium alloy zinc manganese zirconium alloy. Mainly used in aviation, aerospace, transportation, chemical, rockets and other industrial sectors. In practical metal is the lightest metal, magnesium aluminum is about the proportion of 2 / 3, is the iron 1 / 4. It is the lightest metal in practical metal, high strength, high stiffness.
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characteristics of magnesium alloy magnesium alloy used in aerospace applications in the application of digital SLR cameras on the set of patented technology of magnesium alloy magnesium alloy corrosion chemical conversion treatment method of anodic oxidation coatings of metal laser for other surface treatment of magnesium alloy production strategies of fire prevention and fighting of the cutting process of magnesium alloy fire risk in the metal cutting process factors that affect the cutting temperature processing of magnesium alloy cutting chips for fire prevention fire fighting purposesmagnesium alloy sheet Magnesium alloy
characteristics of magnesium alloy and the corrosion process and its mechanical properties have many characteristics: good heat dissipation, light weight, rigid, with some corrosion resistance and dimensional stability, impact resistance, abrasion resistance, attenuation good and easy to recycle; in addition to high thermal and electrical conductivity, non-magnetic, non-toxic and good shielding characteristics. Application: Magnesium alloy is widely used to carry the type of equipment and automotive industries, to achieve the purpose oflightweight magnesium alloy castings 1
. Although the proportion of magnesium alloy weight than plastic, but the unit weight of strength and high elasticity rate than plastic, so the intensity of the same parts in the case of magnesium alloy parts can do better than plastic, thin and light. In addition, the specific strength of magnesium alloy aluminum and iron than high, therefore, does not reduce the intensity components, aluminum or iron components reduce weight. Magnesium alloy compared to the intensity (strength and mass ratio) the highest. Specific stiffness (stiffness and mass ratio) close to the aluminum and steel, much higher than the plastic. In the elastic range, magnesium alloy under impact load, the absorbed energy larger than the aluminum alloy half, so the magnesium alloys have good seismic noise reduction performance. Magnesium alloys with low melting point melting point than aluminum, die-forming performance. Tensile strength of magnesium alloy castings and aluminum castings rather, generally up to 250MPA, up more than 600 Mpa. Yield strength, elongation and aluminum is also less. Magnesium alloy is also a good corrosion resistance, electromagnetic shielding, radiation performance can be achieved 100%magnesium alloy castings 2
recycling. Higher stability of magnesium alloy die casting parts casting line processing of high dimensional accuracy, high precision machining can be. Die-casting magnesium alloy has good formability, die castings minimum wall thickness up to 0.5mm. Adapt to the car manufacturing all kinds of die castings. However, a large linear expansion coefficient of magnesium alloy, to reach 25 ~ 26 μm / m ℃, while the alloy was 23 μm / m ℃, brass of about 20 μm / m ℃, structural steel 12 μm / m ℃, cast about 10μm / m ℃, rock (granite, marble, etc.) is only 5 ~ 9 μm / m ℃, glass 5 ~ 11 μm / m ℃. Magnesium alloy is a magnesium-based alloy by adding other elements. Its characteristics are: low density, high specific strength, elastic modulus, eliminate shock resistance, ability to withstand impact loads larger than the aluminum alloy, good corrosion resistance. Main alloying elements of aluminum, zinc, manganese, cerium, thorium and zirconium or a small amount of cadmium. Currently the most widely used is magnesium alloy, followed by magnesium and magnesium alloy zinc manganese zirconium alloy. The proportion of magnesium alloy used in all structural alloys are the lightest, therefore, does not reduce the intensity components, aluminum or iron components reduce weight. Magnesium alloy significantly higher than the strength of aluminum and steel, aluminum and steel than the stiffness and quite. In the elastic range,[url=http://www.uggonlineoutlet.us/][b]title=UGG Outlet[/b][/url], magnesium alloy under impact load, the absorbed energy than aluminum pieces large, so the magnesium alloys have good seismic noise reduction performance. In the same load, vibration damping is 100 times the aluminum, titanium 300 ~ 500 times. Excellent electromagnetic shielding, 3C products, housing (phone and computer) to be able to provide excellent protection against electromagnetic effects, and magnesium alloy enclosure and completely absorbed over 100db frequency electromagnetic interference. Texture, appearance and touch of magnesium alloy excellent texture, make our products more luxury, and, in the air are less likely to corrode. Magnesium alloy heat relative to alloy it has the absolute advantage: According to the formula: Q = dvC △ t which Q-heat; d = specific gravity; V = volume; C = specific heat capacity; △ t = (t1-t2) changes in temperature ; when the same size and shape of the magnesium alloy and aluminum, subject to the same heat Q, the ratio of the temperature change between the two: △ t / △ t = 2.74x0.23/1.81x1.05 = 1 / 3; that magnesium alloy of aluminum 1 / 3; magnesium alloy thermal conductivity 54W/mk; aluminum thermal conductivity 100W/mk; difference doubled. Means for the same size and shape of the magnesium alloy and aluminum alloy radiator, a heat production of heat (temperature) aluminum heat sink more easily by the roots to the top of the pass rate, the top easier to achieve high temperatures. That the roots of aluminum alloy radiator with the top of the temperature difference, the heat sink than the magnesium alloy material small. This means that the magnesium alloy material of the heat sink the roots of the air temperature and the temperature difference between the top of the air temperature than the aluminum alloy produced by a large heat sink, thus accelerating the spread of the air convection inside the radiator, the cooling efficiency. Therefore, the same temperature, magnesium alloy heat half the time has not aluminum. Therefore, magnesium alloys are used in LED and other lighting, automotive parts, and other requirements of high quality, high strength, high toughness accessories ideal material. Magnesium alloy used in aerospace applications of magnesium alloys are aircraft, missiles, spacecraft and rockets used in the manufacturing industry lightest metal structure material. Magnesium aluminum light weight, specific gravity of 1.8, the intensity is low, only 200 to 300 MPa (20 to 30 kg / mm 2), mainly for the manufacture of low load-bearing parts.magnesium alloy castings 3
Magnesium alloys in wet air oxidation and corrosion easily, so the parts before use, the surface need to chemically treated or painted. The first German aircraft production and the use of aluminum in the magnesium alloy. Magnesium alloy has a high vibration capability, by the impact load can absorb greater energy, as well as good heat-absorbing properties, which is to create an ideal material for aircraft wheels. Magnesium alloy in gasoline, kerosene and lubricating oil is very stable and suitable for manufacture of the engine gear casing, pump and tubing, because of the rotating and reciprocating inertia force generated was used to make the smaller arm, flaps, doors and control surfaces and other moving parts. Civilian and military aircraft machine, especially the widespread use of magnesium alloy products bombers. For example, B-52 bomber's body parts on the use of magnesium alloy sheet 635 kg, 90 kg extrusion, casting more than 200 kg. Magnesium is also used on some of the missile and satellite components, such as China's Chinese rare earth rich in natural resources, was developed 70 years plus yttrium magnesium alloy, magnesium alloy castings to improve4
strength at room temperature, 300 ° C lower in long-term use in the aerospace industry application. At present, the magnesium alloy parts in automotive applications can be classified into two categories. (1) housing category. Such as clutch housings, valve covers, dashboards, gearbox, crankcase, engine front cover, cylinder head, air conditioners shell. (2) Bracket. Such as steering wheel, steering bracket, brake bracket, seat frame, mirror frame, distribution frame and so on. According to the study, vehicle fuel used in 60% of consumption in the vehicle weight, vehicle weight each reduced 10%, its fuel efficiency can be increased by 5% or more; vehicle weight decreasing by 100 kg, per hundred kilometers can be reduced 0.7 L or so, each 1 L of fuel savings can reduce CO2 emissions 2.5 g, emissions by more than 30%. Therefore, to reduce vehicle weight and energy of the impact on the environment is very large, lightweight car into an inevitable trend. Mobile phones, notebook computer's LCD screen size increases year after year, their branches in the back of the frame and support the use of a magnesium alloy shell. Although the thermal conductivity of less than magnesium alloy, however, several times higher than the plastic, so the magnesium alloy used in electrical products, can be effectively distributed to the internal heat outside. Internally generated heat in the computer and projector and other parts of the shell and the use of magnesium alloy heat. TV on the use of magnesium alloy casing can be done without cooling holes. Electromagnetic shielding: the electromagnetic wave shielding properties of magnesium alloy than in the plastic film on the plating shielding effect, therefore, the use of magnesium alloy eliminating the need for electromagnetic wave shielding film of the plating process. The hard drive read-out devices near the source of vibration on the use of magnesium alloy parts. If the fan blades on the use of magnesium alloys can be reduced to a low vibration sound show. In addition, in order to be in the car after the crash impact and improve the absorption of light weight, the steering wheel and seats on the use of magnesium alloy. Name of AZ91D alloy application characteristics and good corrosion resistance, high strength and electrical products, such as AM60B shell elongation and impact force on the steering wheel and car seats and other AM50A elongation and impact force on the steering wheel and car seats good creep resistance, etc. AS41B auto gear box on the machining performance such as: magnesium alloy than other metal cutting resistance, mechanical processing, processing speed can be faster. Table: Metal cutting resistance (cutting resistance of magnesium alloy 1) name of cutting resistance of magnesium alloy metal alloy 1.8 Brass 2.3 1.0 3.5 resistance to pitting good cast iron: magnesium alloy and other metal resistance to deformation than force, depression caused by the collision is less than other metals. Impact of vibration absorption: magnesium alloy as the absorption of vibration energy performance, use and transmission of the drive components reduce vibration. In addition, the impact energy absorbing performance, better than the elongation of aluminum magnesium alloy, under attack, it can absorb impact energy without generating fracture. Regeneration: different magnesium alloy and plastic, it can be recycled and not simply to reduce its mechanical properties, and the plastic is not hard to reduce its mechanical properties in recycled use. Compared with other metals magnesium, low melting point, specific heat is small, melting in the renewable energy is consumed when the new material the energy consumption of 4%. Table: Comparison of various physical properties of materials, material name density (g/cm3) Melting point (℃) thermal conductivity (W / Mk) Tensile strength (MPa) yield point (MPa) Elongation (%) Young's modulus than strength (GPa) magnesium alloy (Thixoforming) AZ91 1.82 596 72 280 160 8 154 45 AM60 1.79 615 62 270 140 15 151 45 aluminum alloy (die casting) 380 2.70 595 100,315,160,311,771 7.86 1520 carbon steel steel 425,174,002,266,200 plastic ABS 1.03 90 (Tg) 0.2 35 * 40 34 2.1 PC 1.23 160 (Tg) 0.2 104 * 3 85 6.7 types of magnesium alloys in the application of digital SLR cameras on the magnesium alloy as low density, strength than high, with some corrosion resistance, commonly used to frame SLR cameras. Generally high-end and professional digital SLR cameras do take magnesium alloy frame to make it durable, feel good. Such as Canon's 1D series, 5D series, 7D and 10D-50D, Nikon D3 series, D700, Dx00 series and the latest D7000, Pentax K-7 and K-5 are all magnesium alloy body. The magnesium alloy body with a digital SLR camera is not only a symbol of quasi-professional-level professional, also has a high price. By molding method is divided into wrought magnesium alloys and magnesium alloy casting categories. 1, the alloy magnesium alloy name is the name of the main alloying elements and the percentage added to the name. 2, the main components of the alloy (ASTM specifications) alloy name Mg Al Zn Mn Si Cu Ni Fe AZ91D bal. 8.5-9.5 0.45-0.90 0.17-0.4 <= 0.05 <= 0.025 <= 0.001 <= 0.004 AM60B bal . 5.6-6.4 <= 0.20 0.26-0.5 <= 0.05 <= 0.008 <= 0.001 <= 0.004 AM50A bal. 4.5-5.3 <= 0.20 0.28-0.5 <= 0.01 <= 0.008 < = 0.001 <= 0.004 AS41B bal. 3.7-4.8 <= 0.10 0.35-0.60 0.6-1.4 <= 0.015 <= 0.001 <= 0.0035 patented technology sets a magnesium alloy, rare earth ferrosilicon magnesium smelting electric arc furnace step alloy process method 2, aluminum, magnesium alloy solid solution or homogenization heat treatment method 3, the surface treatment of magnesium alloy 4, exclusive processing of magnesium alloy die group 5, magnesium alloy in the application of irrigation equipment 6, magnesium alloys in the manufacturing do alloy doors and windows and their profiles in the application of 7, heat-resistant and flame-retardant magnesium alloy die-casting foundry melting process 8, forming a new forging technology of magnesium alloy 9, magnesium alloy magnesium alloy smelting methodcarving board
10, the magnesium alloy containing aluminum processing into liquid, high corrosion resistance of magnesium alloy surface 11 products and their manufacturing methods, high corrosion resistance of magnesium alloy surface treatment products and their manufacturing methods 12, 13 aluminum-magnesium alloy cable tray profiles , aluminum-magnesium alloy cable tray 14, a color film coated magnesium alloy 15, aluminum-magnesium alloy cable tray sections 16, aluminum-magnesium alloy laptop shell of carbon fiber make up 17 law enforcement, high-strength magnesium alloy and its preparation method 18 dedicated level of magnesium alloy casting machine 19, a magnesium alloy production process 20, a flame-retardant magnesium alloy smelting method of protection 21, 22 magnesium alloy surface treatment, surface treatment 23 magnesium alloy, magnesium alloy surface treatment method and 24 magnesium alloy components, magnesium and magnesium alloy environment-friendly anodizing electrolyte and its application 25, a material used in the preparation method of magnesium alloy ingots 26, a magnesium alloy grain preparation methods and products 27, magnesium alloy 28 die casting method of thin-walled, with mg2si strengthening phase refinement of magnesium alloy casting process 29, the car with multi-resistant magnesium alloy and the casting process 30, an ultrafine grain structure of wrought magnesium alloy method 31 , 32 low-cost heat-resistant magnesium alloy, magnesium alloy solidification surface alloying process 33, 34 magnesium alloy die casting, low thermal cracking tendency of the solid solution strengthening of high-strength cast magnesium alloy 35, low thermal cracking tendency of high-strength magnesium alloy die-casting 36 , magnesium alloy and its manufacturing methodmolded magnesium alloy products
37, with a wet blasting machine processing method 38 magnesium alloy, magnesium alloy refining agents and production methods 39, the coated magnesium alloy molded structure and the coating method, and the coating structure as the outer parts of the application of 40, 41 magnesium alloy scrap special milling machine, an electromagnetic pump filling the low-pressure casting system 42 magnesium alloy, magnesium alloy scrap special CNC milling machine 43, a large cross- bridge from aluminum-magnesium alloy profiles 44, 45 aluminum-magnesium alloy anti-corrosion coating, obscene High purity magnesium and magnesium alloy melting crucible 46, the pressure-flow of high purity magnesium and magnesium alloy melting crucible 47 by calcium - magnesium alloy removed from the molten lead bismuth method of 48, amide-based antifreeze concentrates, and for the protection of magnesium and magnesium alloys containing these concentrates coolant composition 49, magnesium and / or magnesium alloy components of the manufacturing method of 50, magnesium alloy die-casting machine furnace structure 51, helplessness magnesium alloy scrap melting furnace structure and recovery system 52, for the chemical conversion reagent magnesium alloys, surface treatment and magnesium alloy matrix 53, 54 anti-creep magnesium alloys, magnesium alloy and its manufacturing method radiator 55, the airbag steering wheel magnesium alloy frame 56, one with nd-sr cast magnesium alloy and its preparation method 57, a compound used in flame-retardant magnesium alloy deterioration process 58, the surface of magnesium alloy multi-composite oxide film 59 of the oxidation treatment, flame-retardant magnesium alloy coating EPC and its preparation method 60, copper, zinc and aluminum magnesium alloy wire 61, the surface of magnesium alloy composite ceramic membrane 62 and the generation method, magnesium alloy vacuum waste recycling 63 technology and equipment, metal forming technology of magnesium alloy solid-state method 64, the furnace heating solid state diffusion of magnesium or magnesium alloy products, surface alloying method 65, a new type of corrosion resistant zinc-aluminum-magnesium alloy anode material 66 Rare earth, magnesium alloy helmet or helmet and its preparation method 67, with high corrosion resistance of magnesium alloy and magnesium alloy components 68, a tilting type melting furnace casting magnesium alloy unit 69, high ductility magnesium alloy material manufacturing methods 70, magnesium alloy chromium-free chemical preparation method and the conversion coating film-forming solution with 71, 72 robust flame retardant magnesium alloy, with magnesium and magnesium alloy pelletizing method 73, a 74 Preparation of magnesium alloy, magnesium alloy wheels pressure casting apparatus and method 75, one kind of cast magnesium alloy wheels and the melting and molding method 76, a magnesium alloy with a refiner and its preparation method 77, the magnesium alloy metal casting coatings and preparation methods 78, magnesium alloy iron flux and production methods 79 magnesium alloy melting furnace 80, the magnesium alloy scrap material recycling process 81, the magnesium alloy anode oxidation method of ultrasonic 82, copper wire manufacturing method of magnesium alloy 83, a high magnesium alloy cored wire line core agents and the production process 84, excellent liquidity and its magnesium alloy material 85, hot-rolled magnesium alloy sheet manufacturing method and method of 86 hot-rolled magnesium alloy, magnesium alloy sheet processing methods and specialized devices 87, electroless nickel plating on magnesium alloy method 88, magnesium special alloy preparation methods of ceramic foam filters 89, magnesium alloy surface preparation method of uniform polyaniline thin film 90, large-scale melting of magnesium and magnesium alloy products to prevent shrinkage cracks approach 91, in addition to silicon-magnesium alloy flux and production methods 92, magnesium alloy profiles rough, the continuous casting and continuous casting apparatus 93, a magnesium and magnesium alloy ingot casting method 94 for the motorcycle engine on the left rear cover 95 magnesium alloy, in addition to the coating method, method of preparation of recycled magnesium alloy and the regeneration method of coating 96, for the motorcycle engine on the left front cover 97 magnesium alloy for motorcycle engine on the right crankcase cover 98 magnesium alloy, magnesium alloy sheet hot stamping unit 99, a magnesium and magnesium alloy ingots pouring device 100, horizontal cold chamber magnesium die casting machine present, six magnesium alloy base construction has begun to take shape, formed in Chongqing - Magnesium alloy automobile and motorcycle manufacturing, Qingdao - Information and communication product development, Shanghai - Automotive applications, Shenzhen - magnesium alloy die-casting equipment, Liaoning - magnesium oxide and magnesium mineral development, Ningxia - salt lake magnesium resources development layout. Method of magnesium alloy corrosion chemical conversion treatment of magnesium alloy by the chemical conversion coating solution can be divided into: chromate system, organic system, phosphate system, KMnO4 system, rare earth elements such as lines and stannate system. Traditional chromate film of Cr for the skeleton structure is dense, water-containing structure of Cr is a good self-healing, corrosion resistance strong. However, Cr has a greater toxicity, high cost of wastewater treatment, development of chromium-free conversion treatment is imperative. Magnesium treatment in KMnO4 solution obtained amorphous organization of chemical conversion coatings, corrosion resistance and chromate film fairly. Alkaline stannate chemical conversion treatment of magnesium alloys can be used as pre-treatment of electroless nickel plating, to replace the traditional with Cr, F or CN, and other harmful ions process. Chemical conversion coating of porous structure in the pre-plated activation showed good adsorption, and can change the nickel layer adhesion and corrosion resistance. Department of organic acids obtained by conversion coating process can also have corrosion protection and optics, electronics and other overall performance in the chemical conversion treatment of the new development occupies an important position. Chemical conversion coating is thin, soft, protective capacity is weak, it is generally used as a decorative or protective layer of the middle layer. Anodizing anodizing available chemical conversion better than wear-resistant, corrosion-resistant base coat of paint, and both good adhesion, electrical insulation and thermal shock properties, is commonly used in surface treatment of magnesium alloy technology one. Traditional magnesium alloy anodizing electrolyte generally chromium, fluorine, phosphorus and other elements, not only pollute the environment, but also damage human health. In recent years, research and development of environmentally friendly technology of the oxide film obtained by the more classic anti-corrosion properties and the HAE process Dow17 large degree of improvement. Excellent corrosion resistance from the anodic oxidation of Al, Si and other elements uniformly distributed on its surface, so that the formation of the oxide film has good density and integrity. Generally believed that the existence of pores in the oxide film is affecting the corrosion resistance of magnesium alloy of the main factors. Studies have found the solution by adding to the amount of anodic oxidation of silicon - aluminum sol composition, to some extent to improve oxidation film thickness, density, lower porosity. Sol composition and film speed periodically make rapid and slow growth, but basically does not affect the film X-ray diffraction phase structure. But the anodic oxide film of brittle, porous, difficult to obtain in a complex piece uniform oxide film. Metal-coated magnesium and magnesium alloy plated metal is the most difficult, for the following reasons: (1) the formation of magnesium alloy magnesium oxide surface easily, easily cleaned, seriously affect the coating adhesion; (2) the electrochemical activity of magnesium is too high, all the acid bath will cause rapid corrosion of magnesium matrix, or replaced with other metal ions was very strong, after the replacement of the coating with very loose; (3) The second phase (such as rare-earth phase, γ equal) with different electrochemical properties, may lead to uneven deposition; (4) coating is much higher than the standard potential magnesium alloy substrate, any one hole will increase the corrosion current, causing serious electrochemical corrosion, while the electrode potential of magnesium is very negative, Shi plating caused by hydrogen evolution is difficult to avoid pinholes; (5) the density of magnesium alloy castings are not very high, the surface impurities are present, may become a source of coating porosity. Therefore, the general method of chemical conversion coating of zinc or manganese, the first dip, then copper, then the other plating or chemical plating process, to increase the coating adhesion. Magnesium alloy plating layer with Zn, Ni, Cu-Ni-Cr, Zn-Ni and other coatings, chemical coatings mainly Ni-P, Ni-WP and other coatings. Sometimes a single layer of electroless nickel magnesium alloy to protect well enough. Studies by electroless Ni plating layer and the alkaline Zn-Ni coating composition, about 35μm thick coating after passivation can withstand 800-1000h after the neutral salt spray corrosion. It was also used as the underlying electroless nickel plating, nickel plating and then the DC can be microcrystalline nickel, the average crystal grain size of 40nm, leaving the coating due to grain refinement greatly reduced porosity, structure is more compact. Plating or chemical plating for superior corrosion resistance simultaneously and electrical, electromagnetic and decorative properties of the surface treatment. Drawback is that pre-treatment of Cr, F, and bath and environmental pollution; coating contains heavy metals in the majority, increasing the difficulty and cost recovery. As the magnesium matrix characteristics of the binding force also needs to be improved. Laser treatment, laser treatment are laser surface heat treatment and laser surface alloying two. Laser surface heat treatment, also known as laser annealing, actually is a surface treatment of rapid solidification. The laser surface alloying is a new laser-based surface heat treatment technology. Laser surface alloying can get different hardness of the alloy layer, with a metallurgical bonding interface. The use of laser irradiation effects in high-purity source of magnesium alloy cladding can be obtained on single and multi-alloy layer. The use of broadband laser in the magnesium alloy surface preparation Cu-Zr-Al alloy cladding coating, the coating formed in a variety of intermetallic compounds to enhance the role of the alloy coating has high hardness, elastic modulus, wear and corrosion resistance. And because the presence of rare earth elements Nd, after laser treatment after the rapid melting of laser multi-layer coating, the grain has been significantly refined, can improve the cladding layer of dense and integrity. Laser treatment can deal with complex surface geometry, but the laser processing of magnesium alloys prone to oxidation, evaporation and the resulting vaporization, porosity and thermal stress problems, design the right treatment process is essential. Other surface treatment technology ion implantation in high vacuum, in the ten to hundreds of KV voltage electrostatic field, the high-energy ions accelerated by the (Al, Cr, Cu, etc.) to deal with high-speed impact into the sample surface and internal the method. Ions are injected in the sample and remain in solid solution and the space or gap position, the formation of non-equilibrium surface layer. Some studies show that the improvement of corrosion resistance is due to natural oxide densification and the formation of radiation into the ion magnesium nitride results. The performance obtained with the modified layer into the ion volume and the thickness of modified layer, and the MgO substrate surface modified layer to improve corrosion resistance but also have a role in promoting. Vapor deposition is evaporation deposition coating, physical vapor deposition (PVD) and chemical vapor deposition (CVD) two. It is used to make magnesium alloys Fe, Mo, Ni and other impurities significantly reduced, while the use of coating covering a variety of defects in the substrate, to avoid the formation of localized corrosion cell, so as to achieve the purpose of improving the corrosion resistance. Magnesium alloy with other surface treatment technology, organic coating protection technology with diverse varieties and colors, wide adaptability, low cost, simple process advantages. Widely used are organic solvent-based coatings. Powder-based coatings for organic solvent-free, and with less pollution, thickness uniformity and better corrosion resistance, etc., in recent years in the automotive, computer housings and other parts of the application of magnesium alloy more popular. Magnesium alloy die castings because lack of clamping force, clamping bad, insufficient strength of the mold, and other issues too high melting temperature of soup there will be glitches surface phenomenon, a phenomenon called the product disclosure front, often companies will have to face the post-processing processing operations now are mainly based on the nature of the use of hand-polished product, hydrogen explosion, and Zhao Ling frozen shot blasting machine to solve the production of magnesium alloy fire prevention and fighting measures magnesium alloy cutting process 1.1 chips for fire hazard properties of lively, very high temperatures easy to burn. Magnesium alloy cutting process, chips for most of the incision is not oxidation of magnesium and magnesium alloys. Since magnesium is a case of wet combustible materials, ignition point and the minimum ignition energy is low, combined with a small chip thin, large surface area, so the high temperature combustion in the air easily. 1.2 high-speed cutting will produce heat, ignition of magnesium shavings. Machining, the cutting tool to give full play to improve production efficiency and quality of the workpiece, normally require a higher cutting speed. The high-speed cutting of metal chips tend to make temperatures up to 700 ° C ~ 1 000 ° C, when the lack of effective supply of coolant, the heat will be sufficient to ignite the magnesium shavings on fire. 1.3 chips for high-temperature combustion, the fire spread fast, fighting difficult. Magnesium in the event of fire, the combustion temperature of up to 3 000 ° C, heat of combustion value of up to 25 121 kJ / kg. When the chips were powdered magnesium when mixed with air in a fire can explode. In addition, magnesium and high temperature chemical reaction with water may release hydrogen gas, so the magnesium fire, water, foam, carbon tetrachloride and other extinguishing agents are subject to restrictions, dry powder, Halon extinguishing effect is not obvious, the difficulty of fighting large. Metal cutting process factors that affect the cutting temperature metal cutting process, cutting deformation and 99% of the power consumed by friction into heat, can be used (1), said: Q total = Q1 + Q2 + Q3 (1) where : Q total - the total heat generated during cutting, also known as cutting heat; Q1 - deformation changes in the power consumed by the heat; Q2 - the rake face and chip surface friction calories; Q3 - flank and chip surface, the heat consumed by friction. Cutting heat primarily through the chip, tool, workpiece, cutting fluid (such as coolant, lubricant) and the surrounding air conduction out, when without cutting fluid, then most of the heat from the chip came out. Magnesium alloy machining processes control the cutting of fire prevention 3.1. Cutting heat generation was the same proportion with the increase of cutting speed, cutting speed on cutting temperature so great. In practice, we found that the different cutting speed the cutting heat generated by the surface oxide film will chip the color change. Thus, by cutting under different cutting magnesium oxide film color can estimate the safety of the lathe spindle speed. 3.2 Choose the correct cutting fluid. Unless the mechanical structure itself is limited, the magnesium alloy cutting should always be an adequate supply of cutting fluid and chips at lower temperature. Taking into account the chemical properties of magnesium, cutting fluid selection should avoid using combustible, with a strong oxidizing and higher water content of the liquid, thereby preventing the cooling fluid when the temperature exothermic reaction of magnesium shavings burning or fire. 3.3 strengthen flammable, combustible materials regulation. Cold cutting process used in lubricants and hydraulic fluids used in precision machine tools, rail oil, spindle oil, mostly flammable liquid, and generally have a larger storage capacity, such as general machine tools hydraulic oil of about 20 kg ~ 70 kg. Therefore, the device should be strengthened in the daily work of repair and maintenance to keep machines in good condition to prevent leakage. Left after the clean machine oil cloth, cotton oil,[url=http://www.ugg-onlineoutlet.com/][b]title=UGG Online[/b][/url], etc., should be promptly cleaned up and isolated with magnesium shavings. Chips for fire fighting 4.1 Do not use water, foam, carbon tetrachloride, carbon dioxide fire extinguishing agent to fight the blaze. 4.2 pairs have been burning magnesium shavings should be used in Class D fire extinguisher. Such as 7150, D class powder, dry sand, etc., taking into account the current domestic market 7150, D type dry powder fire extinguishers are not common, and dry sand on the machine (especially the precision machine tools) damage to the large, can make the best choice based on the actual 75% ~ 80% of the flux powder with 20% coverage to 25% sulfur powder made by mixing powder portable fire extinguisher in the flux in filling out the fire, the effect is obvious. 4.3 chips for fire fighting should be made with fire extinguisher nozzle to maintain a certain distance between the magnesium shavings to minimize fire extinguisher spray process the impact on the role of magnesium dust, magnesium dust to prevent the spread of the formation of explosive mixtures. ① use of magnesium alloy sheet magnesium alloy sheet is the aerospace industry indispensable material. The economic benefits of aviation materials, weight and performance improvement is significant, commercial aircraft and bring the same quality fuel vehicle weight savings, the former is nearly 100 times, and aircraft fuel cost savings is close to commercial aircraft 10 times, more importantly, improve their mobility can greatly improve their combat effectiveness and survivability. Because of this, the aviation industry will adopt various measures to increase the magnesium alloy applications. Now used in aircraft, aircraft aluminum about 85% of the total weight, high strength, corrosion-resistant aluminum magnesium alloy performance than better advantage in aircraft applications. ② magnesium alloy is to reduce the quality of weapons and equipment, weapons and equipment to achieve light weight, the tactical weapons and equipment to improve the performance of the ideal structure of materials. On military applications, such as helicopters, fighters have a lot of use; tanks, armored vehicles, military jeeps, weapons, firearms, etc., integrated combat system allows man down 6.37Kg. Magnesium board manufacturing bullet casings, shell casings, bullet load the man doubled. ③ transport applications, such as cars, trains, ships, etc., to reduce weight, save energy, reduce pollution, countries are to develop. ④ widely used in 3C products. ⑤ In the power supply applications, magnesium products are high-energy non-polluting power supply, such as the manufacture of magnesium manganese dry batteries, magnesium air battery, magnesium seawater battery, torpedo and battery power. ⑥ high potential magnesium sacrificial anode to protect the plate with the metal. ⑦ civilian is also very wide. Such as green building decorative plates, sports, medical equipment, tools, advanced frames, watch cases, travel accessories and other high-level entryAtlas Atlas entry for more pictures (8)
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