飼料自動(dòng)混合攪拌機(jī)設(shè)計(jì),飼料自動(dòng)混合攪拌機(jī)設(shè)計(jì),飼料,自動(dòng),混合,攪拌機(jī),設(shè)計(jì) FSW-C Current Status and Development 1 Preface In 1991, the British Welding Research Institute (The Welding Institute-TWI) invented the FSW (Friction Stir Welding-FSW), the invention is excellent welding technology advances in manufacturing technology for the world to contribute. At Abroad, friction stir welding has been achieved in many large-scale manufacturing, the application level of industrialization. Areas such as shipbuilding, in 1996, friction stir welding in Norway MARINE successfully applied to fast ship aluminum deck, side panels and other structural parts of the assembly line manufacturing. In the rail equipment manufacturing field, the first Japanese company in 1997 HITACHI friction stir welding technology in the train body fast low-cost manufacturing, successful implementation of a large panel of industrial aluminum profiles manufacturing. Aerospace manufacturing in the world, instead of friction stir welding has been successfully implemented large-scale fusion, such as launch vehicles and space launch vehicles and other large-scale space shuttle fuel tank manufacturing high strength aluminum, Boeing DELTA II rocket type and IV have all been Friction stir welding manufacturing implements, and in 1999 the first successful launch. 2000 world automotive industry, automobile companies, such as the U.S. TOWER on the use of friction stir welding to achieve the car hanging bracket, light alloy wheels, anti-collision buffer, engine mounting bracket and the aluminum body of the weld. August 2002, the United States Air eclipse technology developed by the entire FSW FSW light commercial aircraft, and the first successful test flight. 2 The technical characteristics of friction stir welding The technical characteristics of friction stir welding friction stir welding as a new welding method, using a very short time to complete the invention to the industrial application from the course. At present, no international publication for the unity of friction stir welding technology terminology standards, patent licensing in the friction stir welding under the influence of the Association, the industry has been friction stir welding method of the involved technical terms are defined and recognized. The following figure shows the use of friction stir welding of the main descriptive terms. FSW is a frictional heat in the mechanical and solid under the action of the connection method. Shown in Figure 1, friction stir welding process, a cylindrical shaft with a special convex shoulders and pin head spinning slowly stirred into the workpiece to be welded, welding materials mixing head and is the shear resistance of the friction between the friction heat generated , So that mixing the first neighborhood of thermal plastics (welding temperature normally does not reach and exceed the melting point of welding materials), when the mixing head spinning move forward, the hot plasticized metal back from the forefront of the pin Along the transfer, and in the mixing head shoulder and the workpiece surface friction and heat and forging together, form a dense solid connectors FSW with automation and robotics operations for the many advantages, for non-ferrous materials (such as aluminum, copper, magnesium, zinc, etc.) connection, welding, mechanical properties of joints and productivity that has no other welding methods Compare the advantages, it is an efficient, energy saving, environment-friendly new connection technology. However, friction stir welding also has its limitations, such as: weld at the end there is usually a key hole (hole-free now for welding); large mechanical force during soldering, welding equipment need to have good rigidity; and arc phase Ratio, the lack of flexible welding operations; can not be achieved filler metal welding. FSW adaptability of materials, almost all types of aluminum alloy welding, friction stir welding process because the lower temperature and smaller welding heat input, the general deformation of friction stir welding head with a small, joint performance And so on; to fusion welding current "can not be welded, " and so-called "hard to weld" the metal materials such as: Al-Cu (2xxx series), Al-Zn (7xxx series) and Al-Li (such as 8090,2090 and 2195 aluminum Alloy) and other aluminum alloy. In addition, friction stir welding for magnesium alloy, zinc alloy, copper alloy, lead alloys, and aluminum matrix composites and other materials, the connection plate butt or lap welding method is preferred; present, friction stir welding has also successfully achieved Stainless steel, titanium or high-temperature alloys high-quality connections. Fsw of dissimilar materials can be more easily achieved the connection, such as aluminum and stainless steel by friction stir welding, the use of friction stir welding of aluminum can be more easily achieved - the connection between steel plates and copper and aluminum composite joints. 3 FSW development abroad FSW in the development of friction stir welding abroad as a preferred light alloy welded connection technology, has moved from technical studies, into a high level of engineering and industrial application stage, the formation of a new industry: friction stir welding equipment Manufacturing, processing and friction stir welding products. If the aerospace manufacturing industry in the United States, the Nordic shipbuilding industries, manufacturing, and other high-speed train in Japan manufacturing, friction stir welding has been widely used, have been the formation of new industries. 4 Laser assisted friction stir welding Laser assisted friction stir welding (LAFSW) is a new and improved friction stir welding, friction stir welding is a technique developed nearly 10 years. In friction stir welding, the welding heat from the heat of friction between tool and workpiece. Since this process requires a relatively large force, therefore, the use of friction stir welding equipment cumbersome and expensive. Laser assisted friction stir welding using laser energy heating the workpiece, and the pin connecting the main role is to stir and the workpiece 2. For this reason, laser assisted friction stir welding is a relatively simple and inexpensive methods. In order to overcome the friction stir welding deficiencies, such as (1) welding the workpiece clamping fixture larger force to move forward requires a lot of welding tools, welding tool wear rate is relatively high; (2) the method of induction heating coil is not To ensure the correct position, welding mixing head and fixtures are subject to the impact of the induction coil and heated by induction coil for heating and only for the media conductor material, and can not be used for other non-metallic and non-conductive material. It has developed a laser assisted friction stir welding. This approach by the general milling and Nd: YAG laser converted into a. Laser energy in the rotating mixing head warm in front of the workpiece within a limited range. In this way, rotating the workpiece in front of the volume mixing head, the plastic increase (Figure 1). Then, the FSW process and ordinary connection the same way as the workpiece. Softening the front rotary tool workpiece, and clamping fixture may not be able to guarantee a strong connection. Welding tools to move forward only a small force, so a reduction of wear and tear. The advantages of this technology of laser energy also welding with higher welding does not cause excessive wear and tear. Commercial use of the laser, the laser has a very precise diameter control device, therefore, control of the workpiece and the laser heat source to reach the regional number of jobs and keep other parts of the heating system is relatively easy. Currently laser assisted friction stir welding of the welding process has been proven. Preheat the workpiece to the use of laser marks in the welding tool and the workpiece in the need to provide a larger reduction in force, with this improved method simplifies the use of, the use of economical welding method is possible. In addition, the higher the welding speed to obtain a better in improving the efficiency. 5 FSW - Aluminum high-connectivity ZL114A alloy widely used for the Chinese Center for friction stir welding of the friction stir welding process of adaptation to the development, test data show that the friction stir welding process well adapted, the joint tensile strength of the base metal 91 %, overall performance is better than the mechanical joints such as electron beam welding methods. ZL114A alloy (the old grade is ZAlSi7Mg1A), is based on the increase in ZL101A Mg alloy element content developed Al-Si-Mg system high strength cast aluminum alloy. It has excellent casting properties, but also has higher than the mechanical properties of ZL101A alloy. Because of its superior characteristics, in the aerospace manufacturing industry, the important parts are widely used in the manufacture of large thin-walled structure. ZL114A alloy and promising, resulting in high connectivity for the urgent material needs. By using fusion method, a large amount of heat input, welding deformation, difficult to meet the requirements of thin-walled precision parts; and prone to weld porosity, slag, lack of penetration, burn, cracks and other defects, defect rate; and treatment before welding after welding process more cumbersome. Friction stir welding is a new solid metal connection technique, the metal is not melted during the welding process, a small amount of heat input; weld metal connection is accomplished by squeezing the state, the welded joint does not produce fusion welding pores and cracks, welded joints, and other similar defects, fewer weld defects; similar mechanical friction stir welding process, easy automation, and does not melt welding voltage, current, light, metal dust and other phenomena, the work environment environmental cleaning. The most important is that friction stir welding is superior to the mechanical properties of welded joints. Experimental data show that the tensile strength of welded joints for 91% of the base material, the specimen extension rate of 2.5%, joints grain refinement, uniform and compact, eliminating the base metal casting defects. ZL114A base metal and welded joint microstructure compared to the weld nugget zone can be observed microstructure is no direction, and small equiaxed grains, base metal as a coarse dendritic cast structure. Friction stir welding is a welding and mechanical connections different from the melting of new welding technology, based on its technical advantages in the aviation industry in the application of great potential, for a variety of light alloys and efficient connectivity, and provide a solution methods. 6 FSW applications in launch vehicles Launch vehicle tanks commonly used material is high specific strength and stiffness than aluminum, such as 2014,2219 and 7075 aluminum alloy. Now, the launch vehicle performance and better use of the tank and aluminum-lithium alloy 2195. Aerospace products, especially in the manufacturing launch vehicle tank, the welding process is a key manufacturing technology. Welding techniques such as gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) 50 years since the 20th century onwards, Thor, Atlas, Titan, Saturn and the Delta series of launch vehicles used in the manufacture of tanks Decades, from welding equipment, welding materials, welding technology has done a lot of research work to meet the needs of the welding quality. Meanwhile, in order to improve the welding quality and reduce costs, the 20th century, the United States has adopted 80 of variable polarity plasma arc welding (VPPA) welder, and equipped with advanced computer control system to replace the GTAW and GMAW, welded 2219-T87 Space shuttle external tank, aluminum alloy, so that the welding process in the manufacture of the tank a big step forward. So far, though improved weld quality, weld time has been shortened, but still not completely solve the weld and the crack near the weld area and reduce the porosity and other weld defects. University of Cambridge in 1991, Welding Institute (TWI) the invention of friction stir welding (FSW). The welding deformation of aluminum alloy welding, metallurgical and mechanical properties, low cost and welding time is short. Norway first in the world with FSW welding technique had 6 mm × 16 m2 of 6068-T6 aluminum panels and 20 m long ship's boats, aluminum alloy, welding total length of 10 000 m. Switzerland has developed a FSW welding machine. FSW welding technology in order to accelerate the industrial application, in 1995 co-sponsored an international program led by the TWI Institute continue to study the FSW, and with the Department of FSW welded 2000 (Al  Cu), 5000 series (Al  Mg), 6000 (Al  Mg  Si) and other aluminum alloy, and welding quality are satisfactory. TWI Institute, United States Edison Welding Institute (EWI) and other departments, in addition to welded aluminum alloy FSW for research, but also use it to study welding ferrous metals and other metals. U.S. aerospace industry sector F SW carried out more applied research, such as the Luo  Martin, Boeing invested a lot of development costs, only spent FSW welding process and equipment development and the costs amounted to $ 15,000,000 The successful welding of the Delta launch vehicles Ⅱ ~ Ⅳ tank. Since FSW is welded alloy melting point than the low temperature solid-state under the conditions of complete connection, so there is no melting of metallic materials, welding and mechanical properties of small shrinkage loss is low, and the fusion of traditional GMAW and GTAW welding aluminum technology compared to Has outstanding advantages: a) do not need to argon, helium, shielding gas and filler material, welding need to control the welding current and arc voltage parameters, saving a lot of material consumption. b) do not need to be before welding wire welding material and careful cleaning, pickling, polishing and drying, do not have to be welded material machining profile mouth open and save a lot of operating time. c) does not require a high welding technique. d) welding energy efficient, single-layer welding 6000 series aluminum alloys up to 12.7 mm thickness, and therefore suitable for automated production. e) there is no major defects in aluminum alloy welding, the crack sensitivity of the issue, therefore, easy to difficult welding of aluminum alloy welding materials, such as 7075 aluminum alloy. f) Since FSW metallurgical properties of the alloy can be maintained, so I can weld metal matrix composites and rapidly solidified materials. g) to adopt the best welding parameters, pore-free weld can be obtained. h) can weld dissimilar metals, such as casting and extrusion, casting and forging materials. i) can be welded by FSW welding many often can not be a long and large cross-section parts. J) Large size extrusion welding deformation is small. k) the workpiece before welding, assembly requirements low, the surface of the roots do not have to be welded tight fit, the root of the assembly gap tolerances low, 1.6 mm thickness of the plate assembly space for the roots of 0.2 mm, 12.7 mm thick as 1.25mm. FSW is a welding aluminum is suitable for new technologies. Because it is a solid-state welding technology and welding aluminum, compared with three main advantages: a) elimination of solid-state connection with welding the cracks, that is, liquefied or solidified cracks. Optimum welding conditions in the complete elimination of porosity. b) there is no weld metal evaporation loss of alloying elements, the weld alloy elements are preserved, so the welding quality is guaranteed. c) the welding tool on material produced by crushing, stirring and forging the role of the base metal can be obtained more than fine recrystallized weld metal strength over the HAZ material strength. The material used for launch vehicle tank with high-strength aluminum alloy 2014-T6 (China grades for the LD10) is more difficult to weld metal material, the welding hot cracking tendency of high, welded joint strength factor of about 0.5, the plastic is not high, extending rate of 2% to 3%, welding performance is poor. FSW joints welded bend specimens after the proof: the plastic joints significantly improved, bending angle of 180 °, tensile specimens were broken in the weld metal beyond the heat affected zone. 2014-O state of tensile specimens were broken in the destruction of the base metal. Compared with the welded joints, FSW tensile strength of welded joints and 30% to 50%, welded joint strength factor of 0.7, fracture toughness, fatigue performance and riveting of the same. High-strength aluminum alloy 2519-T87 has excellent impact properties, for the Navy's amphibious attack tanks advanced, but with ordinary welding, the welded joints of low plasticity, the impact can not be acceptance test, after welding by the FSW than the welded joints of welded joints to improve plasticity, strength the same, successfully passed ballistic impact test. 2195-T8 Al-Li alloy by FSW welding, mechanical properties of welded joints than VPPA mechanical properties of welded joints is much higher. FSW has developed rapidly, over 10 years. Since 1995, Europe, the United States and Japan and other countries to carry out the application of FSW research, especially in the U.S. aerospace industry attach great importance to the technology and used it successfully in the past is difficult to weld 7075 aluminum alloy welding of cryogenic fuel tank its good mechanical properties. 5454 aluminum alloy after welding has good corrosion resistance. Different countries are studying the current alloy, the shape of the different joints welded, to establish the mechanical properties of welded materials database, the establishment of aircraft and aerospace industry with aluminum welding standards, and broadened the application of FSW to cars, shipbuilding, railways, construction, pressure vessel and other departments. At the same time of high melting point of titanium materials, including metal-based materials, including the welding of aluminum alloy foam. FSW welding equipment mainly depends on completion of the study focused holder and the special type that sticks. Studies have shown that: Tools determine the shape of the weld metal plastic heating, the flow of thermoplastic material and forging forms; holder size determines the size of the weld, welding speed; tools and materials determines the friction heating rate, grip strength the workpiece temperature; so gripper determine the final weld quality. Patents in various countries, in order to weld the best mechanical properties and metallurgical properties, completely non-porous, smooth surface of the weld on a variety of special type refers to the shape of rods were made of; of the cylindrical clamping the diameter 2rs, geometry, welding speed ω, the downward force F, and welding materials with the thickness W of the best studied, and reached the following conclusions: FSW is a very suitable for the latest technology in welding aluminum, a welding deformation of small, high quality and low cost. Although the development time is not long, tank manufacturing and other fields in the launch vehicle applications have been received, and further expanded. Because of this welding process in the importance of the aerospace industry sector, but also great potential, the current critical welding parameters and tool technology is still in the secret stage. China should be undertaken as soon as possible FSW research in the aerospace industry for high strength aluminum alloy product.