It has good development prospects. At present, the electrical steel vacuum coating technology becomes mature and quickly realizes the industrialization of vacuum coating technology.
Practice has proved that steel vacuum electron beam coating has many advantages: (1) choice of zinc oxide material melting point without much restriction. High energy density electron beam can make the coating material in a very short time to reach 3000 ~ 6000 . Therefore, in addition to common galvanized hot dip galvanized, aluminum, tin, almost all of the metal materials can be deposited, but also a wide variety of plated metal nitride film, metal oxide film and metal carbide and a variety of composite membrane. This strip material for the development of new offers great freedom. (2) Coating of high material utilization, environmental pollution. Vacuum coating is a dry coating, no harmful liquids, gases. (3) Steel coating has good quality. It access to uniform, smooth and very thin coating, coating of high purity, corrosion resistance and adhesion. Strip coating by electron beam warm-up prior to surface activation, coating of high purity, and no intermediate brittle alloy layer can be a metal forming, and even rolled into a small tube rather than directly by the coating off. (4) process flexible, easy to change varieties, according to product requirements to achieve a flexible steel plating on single-sided, double-sided, single layer, multilayer, plated two materials can reach plated mixed film. Coating thickness is easy to control, and ultra-thin films can be coated.
However, the steel vacuum coating is still in early stages of development. The share of the strip surface is still far and hot-dip, plating compared. Hinder the development of vacuum coating strip is mainly due to low productivity, high cost. The most effective solution is developed high-speed, high power and stable evaporation source.
The development of high-power electron gun and vacuum coating with Plate conveyors Manufacturers a strip of key technologies. General vacuum evaporation coating resistance heating can be used and induction heating. Its equipment is relatively simple, but the heating temperature and the evaporation rate are low. Industrial production to meet the continuous need for vacuum coating steel strip, you must use heating speed, high melting temperature of the heat source.
Experiments prove that high-power electron gun is the ideal heat source in continuous vacuum coating process. This is because: Electron gun emitted after electron beam can be achieved by focusing a high energy density, bombardment crucible coating material, so the temperature can reach 3000 or more, than the high temperature arc. Electron beam energy conversion rate of 80% -90%, using the magnetic deflection system can be easily e-beam focusing and scanning, uniform heating. Electron beam bombardment only the surface coating material, not because of the incorporation of other materials caused by mixed problems. Use of the electron gun beam diameter, electric power, plus beam voltage, scan path, frequency and other parameters are easy to implement regulation. Use an electron gun can also be coated in the production process of titanium dioxide steel-plated vacuum was warm, clean and strip electron gun is used, to bombard the surface activation. Though the electron beam scanning, strip surface temperature is controlled at 200 ~ 550 . The preheating is necessary for the steel coating to improve the coating adhesion.
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+ نوشته شده در 1398/1/22ساعت 12:02 توسط vacuuclearn | تعداد بازديد :4