Method for preparing high-gas tightness nickel-copper alloy for travelling wave tube

Abstract

The invention discloses a method for preparing a high-gas tightness nickel-copper alloy for a travelling wave tube and belongs to the technical field of alloy material preparation. The method solves the problem of high difficulty of high-gas tightness nickel-copper alloy preparation. The method comprises the following steps of before electrodeposition, polishing an anode pure-nickel plate and a cathode stainless steel plate by sand paper to remove surface oxides, carrying out ultrasonic cleaning orderly by acetone, alcohol and distilled water to remove impurities such as oil stain on the anode and cathode surfaces and to obtain the clean surfaces, and carrying out nickel-copper alloy electrodeposition by an electroplate liquid comprising 305-350g / L of nickel sulfate hexahydrate, 20-50g / L of copper sulfate pentahydrate, 75-90g / L of sodium citrate, 7-12g / L of sodium chloride, 35-50g / L of boric acid and the balance water under the conditions of a pH value of 5-7, current density of 4-8A / dm<2>, a temperature of 25-45 DEG C, electrodeposition time of 5-15h and a stirring speed of 50-120r / min. The method can prepare the high-gas tightness nickel-copper alloy and has simple processes and easily controllable technological parameters.

Description

technical field [0001] The invention belongs to the technical field of alloy material preparation, provides a method for preparing a high-air-tight nickel-copper alloy for traveling wave tubes, and solves the problem of difficulty in preparing a high-air-tight bulk nickel-copper alloy. Background technique [0002] Traveling wave tube is the main type of broadband and high-power amplifier in microwave vacuum devices. It is widely used in data communication, electronic countermeasures, early warning aircraft, fire control radar, precision guidance and other fields, and plays an irreplaceable role in military electronic equipment. . The amplifying chain of the key components of the traveling wave tube is usually made of nickel-copper alloy material, and the normal operation of the amplifying chain of the traveling wave tube depends on its good air tightness inside. Therefore, the vacuum air tightness of the nickel-copper alloy directly affects the performance of the amplifica...

AI Technical Summary

Problems solved by technology

But the problem lies in the preparation of nickel-copper alloy by traditional casting process. Not only is the process complicated, but also large internal stress will remain inside the casting, forming micro-cracks, which are easy to crack during use and affect the actual performance of nickel-copper alloy castings.

During the smelting process, the melting points of nickel and copper are quite different (the melting point of nickel is 1452°C, and the melting point of copper is 1083°C). When the smelting requirements of nickel are met, copper is smelted at high temperature for too long, resulting in copper and oxygen The reaction produces copper oxide inclusions, which makes the material structure not dense; when the nickel-copper alloy is smelted at high temperature, it is easy to absorb gas, which leads to easy generation of pores in the casting, and it is difficult to ensure that the micro-area density of the material is uniform and free of defects

In addition, in the manufacturing process of the workpiece, after the last process—hydrogen burning process, there are many impurities (carbon, silicon, manganese, etc.) in the nickel-copper alloy, and the distribution is uneven, resulting in inconsistent vacuum airtightness of the finished product; At high temperature, the carbon and oxygen impurities in the alloy react with hydrogen to produce organic matter covering the surface of the finished product, the impurities silicon and manganese are oxidized, and the oxides segregate at the grain boundaries, resulting in intergranular fractures in the finished product, making the gas of the nickel-copper alloy Poor tightness

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