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Aluminum die castings Aluminum die casting is a kind of pressure casting parts, which uses a pressure casting mechanical die-casting machine equipped with a casting mold to pour the aluminum or aluminum alloy heated to liquid into the feeding port of the die-casting machine, and then cast the aluminum parts or aluminum alloy parts with the limited shape and size of the mold by the die-casting machine. Such parts are usually called aluminum die castings. Aluminum die castings have different names in different places, such as aluminum die castings, aluminum die castings, aluminum die castings, aluminum alloy die castings, etc. Because the l aluminum and aluminum alloy have good fluidity and plasticity, and the casting process is cast in the pressure die-casting machine, the aluminum die-casting can make a variety of more complex shapes, and can also make higher precision and finish, so as to greatly reduce the mechanical processing of castings and the casting allowance of l aluminum or aluminum alloy, which not only saves power, l materials, but also greatly saves labor costs; Aluminum and aluminum alloys have excellent thermal conductivity, small specific gravity and high machinability; Therefore, aluminum die castings are widely used in automobile manufacturing, internal combustion engine production, motorcycle manufacturing, motor manufacturing, oil pump manufacturing, transmission machinery manufacturing, precision instruments, landscaping, power construction, architectural decoration and other industries. classification Aluminum die castings can be manufactured into aluminum die-casting auto parts, aluminum die-casting auto engine pipe fittings, aluminum die-casting engine cylinders, aluminum die-casting gasoline engine cylinder heads, aluminum die-casting valve rocker arms, aluminum die-casting valve supports, aluminum die-casting power accessories, aluminum die-casting motor end covers, aluminum die-casting housings, aluminum die-casting pump housings, aluminum die-casting building accessories, aluminum die-casting decorative accessories, aluminum die-casting guardrail accessories, aluminum die-casting aluminum wheels and other parts. Stainless steel balls are widely used in the surface treatment of non-ferrous l die castings, castings, aluminum profiles, auto parts, machinery manufacturing, hardware, pump and valve industries. It mainly focuses on removing the oxide skin on the product surface, burrs on the edge surface, surface roughening, matte fruit, leveling and strengthening, and rust removal. Stainless steel shot, commonly known as stainless steel wire cut shot, is refined by wire drawing, cutting, rounding and other processes. Its appearance is bright, rust free and round (cut shot, cylindrical). Stainless steel shot has moderate hardness, pure ingredients and large coverage. Because it does not have the shortcomings of general cast steel shot, such as pores and abnormal shapes, its service life is longer. The performance of this product can completely replace imported products, and the price is significantly lower than imported products, saving costs for customers. The surface of castings treated with stainless steel shot is bright and clean without rust, and there is no need for post-treatment such as pickling, which is conducive to environmental protection. You can choose two different shapes of products: pre polished round and non pre polished shot. technological process The four basic processes in die-casting aluminum industry are annealing, normalizing, quenching and tempering, which are called "four fires" in die-casting. In the process of die-casting, quenching and tempering are closely related, and both are indispensable. It is understood that annealing is to heat the workpiece. When it is heated to the appropriate temperature, the die casting is cooled slowly according to the different materials selected, so that the internal structure of the l is close to equilibrium. Normalizing is to heat the workpiece to a suitable temperature and then cool it in the air. It is mainly used to improve the cutting function of materials, and it can also be used to end die-casting for some parts that need less. Quenching is to heat and keep the workpiece warm, and then quickly cool it in water or other quenching media such as inorganic salt solution. After this process, the steel parts produced will become hard and brittle at the same time. In order to reduce the brittleness of steel parts, quenched steel parts can be placed at a temperature below 650 ℃ higher than the normal temperature for a long time, and then cooled, which is called tempering. The application of aluminum die castings aluminum materials and aluminum alloys have good fluidity and plasticity, so various die castings with complex shapes and great difficulties can be made. The castings cast with aluminum alloys and l aluminum have high precision and surface finish, which greatly reduces the mechanical processing volume of castings, greatly reduces the labor intensity, and saves electricity and l materials at the same time. Because of its high internal and external quality, aluminum die castings are widely used in automobile manufacturing, internal combustion engine production, motorcycle manufacturing, motor manufacturing, transmission machinery manufacturing, precision instruments, landscaping, power construction, and other industries, and become the new favorite of the die casting industry.

I Human factors: 1. Is the release agent sprayed too much? Due to the large amount of stripping gas, when the amount is too much, it is not burnt out before pouring, so that the volatile gas is wrapped in the surface of the casting. Therefore, under the same conditions, some workers will produce more pores during operation. The demoulding agent with small gas output is selected, the dosage is thin and uniform, and the mold is closed after burning. 2. Overflow trough and exhaust duct are not cleaned frequently? 3 is mold opening too early? Is the mold preheated? Whether all parts are heated slowly and evenly, so that the surface temperature of the cavity and core is 150 ℃ ~ 200 ℃. 4 is there any isolation of products produced when the mold temperature is low at the beginning? 5 if there is no preheating device, whether to use aluminum alloy material to slowly push into the cavity for preheating or use other methods for heating? 6. Whether clean molten aluminum is taken and whether the oxide is injected into the pressure chamber? 7. When pouring, whether the spoon is close to the injection port of the pressure chamber to avoid splashing, oxidation or involvement in air cooling. 8. As soon as the liquid l is poured into the pressure chamber, whether the pressure injection is carried out immediately, and whether the temperature is reduced?. 9. Cooling and mold opening, whether the mold opening time is selected according to different products? 10 is there any fear of using normal die-casting pressure for fear of aluminum liquid flying out (water flying)? I dare not try to increase the specific pressure.? 11 does the operator strictly follow the die casting process? 12 is quantitative pouring adopted? How to determine the pouring volume? II Factors of machine (equipment, mold, tooling): It mainly refers to mold quality and equipment performance. 1 is the design of Die-casting Die reasonable, and will it lead to pores? Reasons for die casting die: 1. Whether the choice of gate position and diversion shape are improper, resulting in the frontal impact and vortex of molten l entering the cavity. (reduce the injection speed and avoid vortex aeration) 2. Is the sprue shape poorly designed? 3. Is the inner gate speed too high, causing turbulence? 4. Is the exhaust blocked? 5. Is the mold cavity too deep? 6. Is the machining allowance too large? Penetrating the dense on the surface, exposing subcutaneous pores? The mechanical cutting allowance of die castings should be smaller, generally about 0.5mm, which can not only reduce the weight of castings, reduce the amount of cutting to reduce costs, but also avoid the exposure of subcutaneous pores. The allowance should not be greater than 0.5mm. In this way, there are basically no pores on the machined surface, because it is protected by a hard . 2 is the exhaust hole blocked and the air cannot be discharged? 3 is there too much lubricant in the punch, or is it burnt? This is also one of the sources of gas. 4. Gate position and diversion shape. Is there any overflow system on the parting surface closed by molten l first? 5 is the position of the inner gate unreasonable? The l after passing through the inner gate immediately impacts the mold wall and generates eddy current, and the gas is drawn into the l flow? 6. The position of the exhaust duct is incorrect, resulting in poor exhaust conditions? 7 is the area of the overflow duct large enough, blocked, and located at the last filling place? Is the exhaust part of the mold often cleaned? Avoid losing exhaust effect due to blockage of release agent. 8 is the mold temperature too low? 9. Is the channel turning smooth? Appropriately increase the inner gate? 10 is there an exhaust plug set at the deep cavity, or is the exhaust increased by splicing? 11 is there any part that is difficult to exhaust due to unreasonable die-casting design? 12 is the total cross-sectional area of overflow gate less than 60% of the total cross-sectional area of inner gate, and the slag removal effect is poor? 13 is it possible to increase the thickness of the inner gate to reduce the filling speed under the condition of satisfying good molding? Is there any high speed of the inner gate, excessive turbulent movement, and serious involvement of l flow into gas? 15 is there any inner gate with too small sectional area and serious spraying? Whether there is sequential filling to facilitate the discharge of cavity gas, and whether the sprue and runner have sufficient length? III Material factors: 1. Is the composition of raw materials of suppliers well controlled? What is the iron content? (below 0.7) 2 is the purity of aluminum guaranteed? 3 is the secondary material (nozzle material) used too much and the slag removal action is not done well? 4. There is no excessive waste slag ladle added to the molten aluminum in the production process, which is poured together with the oxide skin during pouring? 5 does the company control the secondary use proportion of waste materials? How to implement? Who checks? 6 can scrap be added to the aluminum melt of important customer products? 7. Try to change the ratio of new material to recycled material? 8 is the charge clean? IV Method factors: It mainly refers to the pressure casting parameters and operation process. 1 is there any process parameter selected according to different products? (molten aluminum temperature 630-670 o C) reasonably select the die-casting process parameters, especially the injection speed. Adjust the starting point of high-speed switching. 2 is there any reduction in the moisture content of demoulding oil? Is there a mold release agent with low gas evolution? 3 is the alloy melting temperature too high? 4 how to measure the temperature of molten aluminum? Is the thermometer accurate? 5 is there a conversion point between the injection speed and the slow injection speed and the fast injection speed adjusted in time according to the product? 6 is there a large machine for casting small parts, and the filling of the pressure chamber is too small? V Environmental factors: Is the air humidity high in the die casting environment? Generally, the hydrogen content in the surrounding air is not much, but if the relative humidity in the air is high, it will increase the solubility of the gas in the molten aluminum and form seasonal pores. For example, in the rainy season, due to the high air humidity, the phenomenon of pinholes during aluminum alloy smelting is more serious. Of course, when the air humidity is high, aluminum alloy ingots, smelting equipment, tools, etc. will also increase the adsorption of surface moisture due to the humidity of the air, so we should pay more attention to taking strong preheating and drying protective measures to reduce the generation of pores. Explanation of terms and small data of aluminum die casting

Die casting machine is one of the necessary machines in die casting factory. Therefore, it is very important for the die-casting factory to choose the die-casting machine and what kind of die-casting machine to choose. 1、 Selection steps of die casting machine 1) Calculate the technical parameters and processability of the die-casting machine according to the technical requirements, service conditions and die-casting process specifications of the die-casting factory, and preliminarily select the appropriate model. 2) According to the technical parameters and process requirements of the die-casting mold initially conceived, the die-casting process parameters and the overall dimensions of the die-casting mold are calculated, and the appropriate model is selected. 3) Evaluate the working performance and economic effect of the die casting machine, including the yield, qualification rate, productivity, stability, reliability and safety of operation. 2、 Selection method of die casting machine In actual production, the choice of die-casting machine is mainly d on the type of die-casting alloy, the size and weight of the casting, and the use of hot chamber or cold chamber die-casting machine. For zinc alloy castings and small magnesium alloy castings, it is usually determined to use hot chamber die casting machine. For aluminum alloy, copper alloy castings and large magnesium alloy castings, cold chamber die casting machine is mainly selected. Vertical cold chamber die casting machine is suitable for castings with central radial and cylindrical shape and the conditions for opening central sprue.

Die casting can produce l parts with complex shape, clear outline and thin wall and deep cavity. Because molten l maintains high fluidity at high speed, l parts that are difficult to be processed by other processes can be obtained. Die castings require high dimensional accuracy, and can be assembled and used after a small amount of machining. Some die castings can be assembled and used directly. The material utilization rate is about 60% - 80%, and the blank utilization rate is as high as 90%. Die casting production efficiency is high. Due to the high-speed mold filling, the mold filling time is short, the l industry solidifies rapidly, and the operation cycle speed of die casting is fast. Among various casting processes, die casting method has the highest productivity and is suitable for mass production. Easy to use inserts. It is easy to set a positioning mechanism on the die-casting die, which is convenient for inlaying the insert and meets the local special performance requirements of the die-casting. All kinds of problems encountered in die-casting production technology, such as the selection of parting surface, the opening of gate, the layout of ejection, the mastery of shrinkage law, the assurance of accuracy, the types of defects and their degrees, are d on the advantages and disadvantages of the process of the die-casting parts themselves.

Die casting die management and maintenance specification 1. Purpose: Strengthen the management of die-casting die, ensure the normal maintenance of die-casting die, ensure the normal production and product quality of die-casting die, extend the service life of die-casting die and reduce costs. 2. Scope of application and responsibilities: All die-casting die management and maintenance of the company. Die casting workshop is responsible for the daily maintenance of molds; The mold repair personnel of the process department are responsible for mold maintenance and repair 3. Operating procedures: 3.1 the die-casting mold must be placed neatly in the specified area and position. 3.2 special personnel shall be responsible for the maintenance, repair and management of die-casting die. 3.3 acceptance of die casting die: 3.3.1 after the new die-casting mold is made, the die-casting mold shall be accepted by the die-casting mold acceptance team according to the technical conditions of die-casting mold. After passing the acceptance, it can be handed over to the workshop. The die-casting mold administrator shall count the gate sleeve, ejector rod, core and other die-casting mold spare parts, mark them and store them by classification. 3.3.2 when the die-casting die is transferred out or transported back to the workshop due to production needs, the die-casting die administrator should do a good job of handover and relevant personnel should do a good job of acceptance. 3.4 die casting mold Archives: After the acceptance of the die-casting die, a "die-casting die use and maintenance archive" must be established for regular inspection and proofreading. 3.5 die casting mold inspection: 3.5.1 for the die-casting die with cooling water, check the cooling water pipe of the die-casting die with tap water, and it should not be blocked or damaged. 3.5.2 check that the sliding block, ejector rod, guide post, etc. of the die-casting die should run smoothly without fracture and stagnation. 3.5.3 carefully check the die-casting mold cavity and parting surface, and the cavity and core are not allowed to have bumps and foreign matters; Aluminum (copper or zinc) slag and dirt are not allowed on the parting surface and exhaust slot. If any, it must be cleaned up. 3.5.4 check the ejector pin push plate and ejector pin fixed plate of the die-casting die. The connection must be firm, and the thread of the pull rod hole on the ejector pin push plate must be intact. 3.5.5 check that the ring screws of the die-casting die must not have cracks, and the ring screws must be firmly connected with the die-casting die. 3.5.6 when closing the die-casting mold, ensure that the reset rod is flush with the parting surface and the core is inserted in place. 3.6 maintenance of die casting mold: The maintenance of die-casting die is divided into daily maintenance and periodic maintenance Daily maintenance is mainly to clean the aluminum slag and dirt on the outer surface of the mold. Periodic maintenance requirements are as follows: After the die-casting die is removed, the die-casting worker must lift it to the designated position for placement, and the die-casting die repairman shall carry out the following maintenance. a) Clean the aluminum (copper or zinc) chips and dirt on the die-casting die (including slider, cavity, core, exhaust system, etc.) to ensure that the die-casting die is clean and the exhaust is unobstructed. Clean the aluminum part and polish it. b) Clean the oil on the mold and cooling water pipe. c) Check the die casting die according to 3.5. d) Repair or replace the bent, cracked and broken cores and ejector rods. e) After each set of die-casting die is pressed and shot for about 10000 times, the scale of the cooling water channel of the die-casting die is removed with descaling agent to ensure the smooth flow of water. f) Each set of die-casting die passes through zinc alloy: about 30000 die times; Aluminum alloy: about 20000 mold times; Regrinding and polishing the surface, and nitriding treatment if necessary; g) Internal stress treatment must be carried out in the mold cavity of each set of die-casting die every 10000 mold times. 3.7 die casting mold maintenance: For the damaged die-casting mold, after the relevant personnel determine the repair plan, the die-casting mold maintenance personnel shall repair it in time. The repaired die-casting mold can be tested only after it is checked and confirmed to be qualified by the relevant personnel. Only after the pressure test piece passes the dimensional inspection (or trial processing and assembly), can the die-casting mold be confirmed to be normal and put into production. And make records. 3.8 maintenance and inspection of die casting mold: The die-casting die repairman must regularly inspect the die-casting die once a month, and make records at the same time. When repairing or replacing the core at ordinary times, records should also be made.