Molding shell preparation process based on microwave dewaxing technology

Abstract

According to the shell preparation process based on the microwave dewaxing technology, the microwave heat effect of a prepared wax mold can be enhanced by adding the nano silicon carbide powder into the wax liquid, so that the wax is quickly lost in the final dewaxing step, the dewaxing speed in the preparation process is increased, and the preparation efficiency of the shell is improved; and according to the overall size of the shell needing to be dewaxed, the shielding covers allowing the shell to pass through different sections are selected, so that the requirement for completely removing a wax mold in the shell is met, and the power consumption of a microwave dewaxing system can be reduced.

Description

technical field [0001] The invention relates to the technical field of investment precision casting, in particular to a mold shell preparation process based on microwave dewaxing technology. Background technique [0002] It is well known that most of the investment casting industry uses high-pressure 0.8Mpa steam to remove the wax mold in the shell, but because the steam source is an oil-fired boiler or an electric boiler, the steam is emptied after dewaxing, so that the mold shell does not crack during dewaxing. , it is usually necessary to preheat the dewaxing kettle to 150 ℃ before it can work, which will inevitably consume a lot of energy, and the temperature in the dewaxing kettle is very high. The wax mold is heated and expanded and cracked, which affects the quality of the casting. Usually, the process requires that the shell reach 0.4Mpa within 14 seconds after loading. There are three processes of closing the kettle door, opening the steam valve, and charging and pr...

AI Technical Summary

Problems solved by technology

(1) Only one shell can be dewaxed at a time. For factory production, the dewaxing efficiency is low, which slows down the overall production progress of castings;

(2) When the wax liquid flows out from the lower side of the metal chamber in the microwave generating equipment, it will remain on the metal wall, and in the high-energy-density metal chamber, the residual wax liquid will quickly carbonize and become a conductor and ignite and burn. In severe cases, electronic ignition and back-bombing will burn internal components such as microwave generators and dewaxing carts in the microwave generating equipment, resulting in complete damage to the device;

(3) Due to the different size and weight of each shell in the actual dewaxing production, that is, the load entering the chamber of the microwave generating equipment is different every time. If only fixed power is used for dewaxing, when the load is too small, it will appear If the energy density in the chamber is too high without load absorption, it will form a lightning-like ignition phenomenon, and in severe cases, the magnetron will be directly burned;

(4) The microwave emitted by a single microwave emission port has a single mode and a single propagation direction in the chamber, so the heating is uneven, which will cause uneven heating of the mold shell and cracks, resulting in dewaxing failure;

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