Precision casting technology (Part 1)
precision casting is a casting method relative to the traditional casting process. It can obtain relatively accurate shape and high casting accuracy. The more common method is: first make the electrode of the required blank (with very small or no allowance), and then use the electrode corrosion mold to form a cavity
cast wax by casting method to obtain the original wax mold. Brush the wax mold with high temperature resistant liquid sand layer by layer. After obtaining sufficient thickness, dry it, and then heat it to melt the wax mold inside, so as to obtain a cavity consistent with the required blank. Then cast molten iron in the mold cavity, peel off the shell after solidification, and you can get the finished product of precision manufacturing
wax loss casting, now known as investment casting, is a casting process with little or no cutting. It is an excellent February 9 process technology in the casting industry, and it is widely used. It is our first time to solve for you. It is not only applicable to the casting of various types and alloys, but also the export growth of China's extruder products will show a stable and progressive situation. The dimensional accuracy and surface quality of the castings produced are higher than that of other casting methods, and even the complex, high temperature resistant and difficult to process castings that are difficult to be cast by other casting methods can be cast by investment casting
Investment casting was developed on the basis of ancient wax mold casting. As an ancient civilization, China is one of the countries that used this technology earlier. As far back as hundreds of years BC, the working people in ancient China created this wax losing casting technology, which was used to cast bell tripods and utensils with various fine patterns and words, such as the zunpan of the tomb of Marquis Yi in the spring and Autumn period. The base of the zunpan of Marquis Yi's tomb is a number of intertwined dragons, which are connected end to end and staggered up and down to form a hollow multi-layer moire pattern in the middle. These patterns are difficult to produce with ordinary casting technology, but with the wax loss casting technology, we can take advantage of the characteristics that paraffin has no strength and is easy to carve. With ordinary tools, we can carve paraffin crafts that are the same as the zunpan of Marquis Yi's tomb, Then add the pouring system, coating, dewaxing and pouring, and you can get the exquisite tomb plate of Marquis Yi Zengmodern investment casting methods were actually applied in industrial production in the 1940s. At that time, the development of Aerojet engine required the manufacture of heat-resistant alloy parts with complex shapes, accurate dimensions and smooth surfaces, such as blades, impellers and nozzles. Because the heat-resistant alloy material is difficult to machine and the shape of the parts is complex, it is impossible or difficult to use other methods to manufacture. Therefore, it is necessary to find a new precision molding process. Therefore, drawing lessons from the lost wax casting handed down in ancient times, through the improvement of materials and processes, the modern investment casting method has achieved important development on the basis of ancient processes. Therefore, the development of aviation industry promotes the application of investment casting, and the continuous improvement and perfection of investment casting also create favorable conditions for the aviation industry to further improve performance
China began to apply investment casting to industrial production in the 1950s and 1960s. Since then, this advanced casting technology has been greatly developed, and has been widely used in aviation, automobile, machine tool, ship, internal combustion engine, gas turbine, telecommunications instruments, weapons, medical devices, cutting tools and other manufacturing industries. At the same time, it is also used in the manufacture of Arts and crafts
the so-called investment casting process is simply to use fusible materials (such as wax or plastic) to make fusible models (referred to as investment models or models), coat several layers of special fire-resistant paint on them, dry and harden them to form an integral shell, then melt the model from the shell with steam or hot water, and then put the shell in a sand box and fill dry sand around it for modeling, Finally, put the mold into the baking furnace and bake it at high temperature (if a high-strength mold shell is used, the mold shell after demoulding can be directly roasted without molding). After roasting, the mold or mold shell is poured with molten metal to obtain the casting
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