Preparation method of metal chromium powder special for high-performance CuCr electrical contact

Abstract

The invention discloses a preparation method of metal chromium powder special for a high-performance CuCr electrical contact. The preparation method comprises the steps of crushing, specifically, a chromium block is placed into a crusher and crushed into granules; screening the granulated chromium block by using a 10-mm aperture screen, and selecting undersize chromium particles; grinding, specifically, the chromium particles are added into low-temperature grinding powder manufacturing equipment, and a cooling medium is introduced to obtain the metal chromium powder; screening again, specifically, the metal chromium powder is respectively screened by using a 200-mesh screen, a 240-mesh screen and a 320-mesh screen; and detecting, specifically, oxygen content in the metal chromium powder isanalyzed by using a nitrogen-oxygen analyzer and is required to be no greater than 600 ppm. According to the preparation method of the metal chromium powder, the oxygen content in the chromium powdercan be effectively controlled; and the chromium powder is not prone to segregation after being mixed with Cu powder, has good formability, and has good wettability of Cr and Cu after sintered.

Description

technical field [0001] The invention relates to the technical field of metal material processing, in particular to a method for preparing a special metal chromium powder for high-performance CuCr electric contacts. Background technique [0002] Chromium is an important alloying element, which is widely used in industry. 15% is used in the production of chemical raw materials and dyes in the chemical industry; 10% is used in high temperature resistance and foundry industries, such as the production of superalloys, electrothermal alloys, precision alloys, stainless steel, etc.; 75% is used in the metallurgical industry to produce highly corrosion-resistant electroplated metal parts, steel, etc. [0003] Copper-chromium contact material is one of the most important medium-voltage high-power vacuum switch contact materials. Metal chromium is an essential material in copper-chromium contacts. The impurity content in metal chromium has a great influence on copper-chromium contact...

AI Technical Summary

Problems solved by technology

During the ball milling process, the material is between the grinding balls that are strongly stirred, and is subjected to the repeated action of impact force, grinding force, shear force and pressure, so that it is continuously deformed, broken and cold welded. This method can be directly used To produce brittle and hard metal or oxide powder; at the same time, it can also deal with the agglomeration of reduction metal powder, atomized powder or electrolytic powder; however, the oxygen content of chromium powder increases after ball milling, resulting in the oxygen content of CuCr contact Higher; 3. Fluidized bed airflow milling method: The material particles are accelerated by compressed gas in the fluidized bed, and are micronized due to the high-speed particle-particle collision. This method can effectively crush the metal powder to 11μm Below, the average particle size is 3.5μm, and the particle size of chromium powder prepared by fluidized bed jet milling method is too fine to be used for CuCr contacts

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