Today, Longhua Die Casting Machine introduces some operation requirements of aluminum alloy die casting machine, let's take a look together! 1. Strictly monitor the die casting process The temperature of the molten aluminum in the holding furnace should be controlled at ± 3 ° C in order to stabilize the stirring temperature. The temperature after stirring must be adjusted according to the chemical composition of each furnace to ensure that the solid phase rate is stable at ± 2%. The temperature of the mold must be checked and controlled so that the alloy can be smoothly filled and orderly solidified. It is necessary to rationally formulate and timely adjust the process parameters of the die casting machine, and make regular inspections on the die casting to ensure the quality of the die casting. 2.Precautions for release agent spraying operation Pay attention to how much paint is applied to the release agent to avoid too much paint, too little or missing paint. More paint can be sprayed on the parts that are difficult to be demolded, and less paint can be sprayed on the parts that are easy to demold. When spraying paint, use a spray gun to move from top to bottom in layers to let the water accumulated in the cavity flow from top to bottom and blow excess water out of the cavity. The cavity is easily adhered to the mold, first spraying at a short distance to cool down, and then spraying at a longer distance to form a coating film. Do not spray too close to prevent paint water from flowing in the cavity. After spraying, use air to blow away the excess and accumulated paint in the cavity, especially pay attention to the paint in deep cavities or dead corners to prevent the water from vaporizing into a large amount of gas after the heat, making the casting appear pores. , Under casting, cold insulation, blistering, this has a very important role in eliminating the occurrence of pores in the casting. 3.Precautions for hot film of die casting machine After using the mold temperature machine hot mold, when starting the die casting hot mold, you can use the liquid alloy low speed die casting hot mold 5-10 mold, and then use the normal semi-solid alloy and semi-solid die casting parameters for die casting production, which can protect the mold, It can also prevent flashing and flying materials.

1. What is shot-to-shot specific pressure and how to adjust it?     Answer: The shot pressure is the pressure per unit area of the metal liquid in the pressure chamber. On the premise of ensuring product quality, use a lower specific pressure as much as possible. The specific pressure of lighting die casting is generally less than 50MPA. The larger the product wall thickness, the higher the specific pressure requirement. The more complex the product structure, the higher the specific pressure requirements. 2. What is shot speed and how to adjust shot speed?     Answer: The injection speed refers to the speed of the injection head during die casting. It is divided into slow injection speed and fast injection speed. Generally speaking, the injection speed refers to the fast injection speed. The size of the slow shot speed is that when the shot head passes through the sprue, it is better not to splash the metal liquid, generally 0.1 ~ 0.5M / S, and the fast shot speed aluminum alloy is generally 0.1 ~ 1.1M / S. The thinner the wall thickness of the casting, the faster the injection speed, the more complex the shape of the casting, the faster the injection speed, the larger the projection surface of the casting, the faster the injection speed, and the longer the casting ball path, the faster the injection speed. 3． What is the pouring temperature and how do I choose a pouring temperature?     Answer: The pouring temperature generally refers to the average temperature of the molten metal poured into the injection chamber and filling the cavity. Generally, the lowest possible temperature is used while ensuring the molding and the required surface quality. The casting temperature of aluminum alloy is 650 ℃ ～ 720 ℃, the casting alloy has good fluidity, and the casting temperature can be lower; the casting temperature of thin-walled and complicated castings can be higher; the mold is large, the heat dissipation is fast, and the casting temperature can be high some. 4． What is the mold temperature, and what is the mold temperature during normal production of aluminum alloy die-casting molds?     Answer: The mold temperature is the temperature of the mold during the production process. The temperature of the aluminum alloy die-casting mold during normal production is: 200 ° C to 280 ° C. Generally, the thinner the casting, the more complicated the structure, and the higher the mold temperature requirements. 5． What is the filling time? How to choose the filling time?     Answer: The time required for the metal liquid to start to fill the cavity is called the filling time. Filling time of aluminum alloy die-casting: 0.01S ~ 0.1S. The principle of selecting the filling time is: (1) the alloy pouring temperature is high, the filling time should be longer; (2) the mold temperature is high, the filling time is longer; (3) if the thick wall part is far away from the inner gate, the filling is The time should be lo...

   In the last part, we talked about the equipment management of the die casting workshop. Today, Longhua Die Casting Machine will share with you another piece of dry goods knowledge: the installation and acceptance of the die casting machine equipment. (1) Installation of die-casting machine According to the drawing requirements of die-casting machine manufacturers, the traditional equipment installation method is to first build the equipment foundation and reserve embedded holes for the feet (see Figure 2). Then, put the anchor bolts into the grout, and then fine-adjust the equipment after the concrete has solidified. After the fine adjustment is completed, it will take some time for the equipment to be used normally after the surrounding oil and water tanks are completed. It basically takes nearly one month. In the actual installation process, considering that the above installation method takes too long, we can completely use the embedded steel structure to install the equipment. (2) Acceptance after installation The acceptance of the die-casting machine must first be based on the contract and the equipment test and acceptance record sheet, which is carried out one by one according to the acceptance items. When the manufacturer debugs the equipment, be sure to send someone to track the test and acceptance and record the test data.    Among them, the accuracy of the coaxiality of the pressure chamber is extremely critical, which directly affects the service life of the punch and the pressure chamber in the later stage. It is a mandatory inspection item for the newly purchased die casting machine. For PLC-controlled die-casting machines, the inspection of the scale-up board is easily overlooked. The function of the proportional amplification board is to control the output current in proportion to the magnitude of the input voltage, thereby changing the pressure and flow of the proportional valve to control the hydraulic system (if it is a single proportional valve, only the pressure is controlled). Specifically, if the total pressure of the digital adjustment system in the control cabinet is 0 to 14 MPa and the total flow rate is 0 to 100%, the pointers of the two ammeters should generally make     corresponding linear changes from 0 to 0.8 A. The linear error is allowed. About 2%. If the linearity error is too large, the linearity of the proportional plate will be insufficient, which will have a great impact on the adjustment of the die casting process parameters.    The supercharging and building pressure time cannot be measured specifically at the production site, and can only be estimated indirectly through the reaction of the pressure gauge pointer of the injection cylinder. The general approach is to adjust the boost delay, flow rate, and airbag pressure at a medium fast injection speed (such as about 3 m / s), watch the pointer of the injection cylinder pressure gauge change, and then close and clo...

  As we all know, the factors that affect product quality are people, machines, materials, law, and environment. The "machine" is the equipment. This article mainly refers to the die casting machine. It is one of the important factors to ensure the quality of the die casting. Without a well-equipped die casting machine, it is impossible to produce high quality die castings. Talking about equipment must involve equipment purchase, acceptance, and subsequent maintenance. Today, Bengbu Longhua Die Casting Machine focuses on a brief description of the equipment management work in the die casting workshop. Procurement of equipment   As the basic technical equipment of die-casting, the die-casting machine has a very important influence on many factors such as product quality, production cost and production efficiency in the production process. For this reason, the detailed selection of die casting machine and auxiliary equipment must be demonstrated. (1) Die casting machine selection Die casting machine selection is actually divided into two cases to distinguish. First of all, for companies that are just beginning to engage in die-casting production, targeted selection analysis should be performed. The main selection basis is the current product that needs to be produced. It can be verified according to related technical standards such as the projected area of the product and quality requirements. Detailed calculations in this regard can be found in some related die casting books. Secondly, for companies that have already purchased some die-casting machines, the selection of equipment for re-purchasing cannot be based on the current production of the product. It should also take into account the company's subsequent development needs and the consideration of the series of die-casting equipment. Sometimes, we will temporarily adopt a "big horse drawn cart" measure and temporarily purchase a larger die-casting machine for production. When the product batch is large and stable, we can customize and increase or decrease the equipment configuration according to the actual demand to achieve the special machine. The purpose of reducing procurement costs and improving labor productivity. (2) Die casting machine performance requirements The parameters of different types of die casting machines will have great differences, and should be selected according to the different needs of various enterprises. Excessive requirements for the performance of the die casting machine will inevitably increase the price of the equipment. For example, the air injection speed of a die-casting machine is a parameter to be considered. For companies that only produce aluminum alloy products, it is not necessary to choose a die-casting machine with an air injection speed of 8.0 m / s or more. Those who need to produce magnesium alloy castings It is obviously inappropriate for a company to choose a die casting machine with an injection speed below 6.0m / s. The performance a...

In modern production technology, die casting is a very common production form. Common die castings are aluminum alloy die casting and zinc alloy die casting. Today, Longhua Technology will briefly introduce the principle of die casting: Die-casting: (Press-casting) is to quickly press a liquid or semi-liquid alloy into a mold cavity under high pressure, and solidify under pressure to obtain a casting; 1. Inject metal First close the mold cavity, and inject metal liquid into the mold inlet through the injection hole on the pressure chamber; 2. Die-casting The injection punch advances, and the metal liquid is pressed into the mold cavity; 3. Take out the casting. After the casting is solidified, the core pulling mechanism pulls out the cores on both sides of the cavity at the same time. Remarks: 1. The mold cavity is made of a special alloy tool steel (such as 3Cr2W8V2), that is, the mold steel; 2. The cavity should be maintained at 120-280 ° C during die casting (depending on the specific die casting material); 3. The specifications of the die casting machine are generally expressed by the size of the clamping force; Of course, there is still a lot of knowledge involved in the process of die casting. It is impossible to understand everything in a small article. This time I just let everyone know the process of die casting. I hope you can pay more attention to Longhua Die Casting Machine and bring you more information.

Longhua uses the world's unique liquid nitrogen (minus -196 ℃) die-casting machine assembly structure assembly process (thermal expansion and contraction), which can completely guarantee that the die-casting machine assembly structure has zero failure rate in production. Liquid nitrogen: liquid nitrogen. It is inert, colorless, odorless, non-corrosive, non-flammable, and extremely low temperature. Nitrogen makes up most of the atmosphere (78.03% by volume and 75.5% by weight). Nitrogen is inactive and does not support combustion. Frostbite caused by a large amount of endothermic contact during vaporization. Under normal pressure, the temperature of liquid nitrogen is -196 ° C; 1 cubic meter of liquid nitrogen can expand to 696 cubic meters of pure gaseous nitrogen at 21 ° C. Liquid nitrogen is a colorless, odorless liquid and gas that is cold at high pressure. Liquid nitrogen (often written as LN2) is a liquid form of nitrogen formed at low temperatures. The boiling point of nitrogen is -196 ° C. If the temperature is lower than normal atmospheric pressure, liquid nitrogen will be formed; if pressurized, liquid nitrogen can be obtained at a higher temperature. In industry, liquid nitrogen is obtained by fractional distillation of air. After the air is purified, it is liquefied in a pressurized and cooled environment and separated by the different boiling points of the components in the air. Nitrogen (78.09% of the volume of air) was first leached (and not liquefied), followed by 0.93% of the rare gas in the air, and finally 20.95% of oxygen. There is no problem with the human skin's direct contact with liquid nitrogen immediately, it will frostbite and irreversible after more than 2 seconds.

There will be some defects when casting the die castings. Today, Longhua Die Casting Machine will take you to analyze the causes and solutions of the defects, and let us take a look. Porosity and Bubble Analysis of Cast Aluminum Alloy Defects Defect characteristics: The pores in the wall of the three castings are generally round or oval, with smooth surfaces, generally shiny oxide scales, and sometimes oil yellow. Surface pores and air bubbles can be found by sandblasting, internal pores can be found through X-ray fluoroscopy or mechanical processing. The air bubbles appear black on the X-ray film. cause: 1. Casting alloy is not stable and is involved in gas 2. Type (core) sand mixed with organic impurities (such as coal dust, grass roots, horse dung, etc.) 3. Poor ventilation of molds and cores 4. Shrinkage on the surface of cold iron 5. Pouring system design for non-casting aluminum alloy defect analysis Prevention method: 1. Correctly control the pouring speed and avoid being involved in gas. 2. Mould (core) sand must not be mixed with organic impurities to reduce the amount of gas generated by the modeling material 3. Improving the venting ability of (core) sand 4.Proper selection and handling of cold iron 5.Improved design of the pouring system Defect features: Shrinkage of aluminum castings generally occurs in the thick parts of the riser root near the inner runner, the thickness of the wall, and the thin walls with large planes. In the as-cast state, the fracture is gray, and the light yellow is grayish white or yellowish or grayish black after heat treatment. It is cloud-like and severely filiform on the x-ray film, which can be found by X-ray, low-fluorescence fracture and other inspection methods. cause: 1. Poor feeding effect of riser 2. Too much gas content in the charge 3.Overheating near the pouring gate 4.Excessive moisture in the sand mold, the core is not dried 5.Coarse alloy grains 6. Casting is not properly positioned in the mold 7. The pouring temperature is too high and the pouring speed is too fast Prevention: 1. Refilling metal liquid from the riser to improve the design of the riser 2. The charge should be clean and non-corrosive. 3. A riser is set at the shrinkage of the casting, and cold iron or a combination of cold iron and riser is placed 4.Control sand moisture and core drying 5.Take measures to refine the granules 6. Improve the position of the casting in the mold and reduce the pouring temperature and pouring speed. Defect characteristics: 1. Casting crack. It develops along the grain boundary, often accompanied by segregation. It is a crack formed at higher temperatures. Alloys with larger volume shrinkage and more complex shapes are prone to appear 2. Heat treatment crack: caused by heat treatment overheating or overheating. Often, alloys with large stresses and thermal expansion coefficients are cooled excessively. Or in the presence of other metallurgical defects cause: 1. The structural design of the casting i...

     2020 is another brand new year, and Bengbu Longhua Die Casting Machinery Co., Ltd. has also embarked on a new journey. At the beginning of the new year, Bengbu Longhua received good news—with a professional team, strong technical strength, continuous innovation ability, and scientific business management, Bengbu Longhua Die Casting Machine successfully passed the international SGS field inspection again.