Preparation method of chromium nitride nanometer powder

Abstract

The invention discloses a preparation method of chromium nitride nanometer powders. The method utilizes the high temperature and etching effects produced by high-frequency induction plasma to realize a chemical vapor synthesis and obtain chromium nitride superfine powders. The method comprises the steps of vacuumizing the whole equipment, producing hyperthermal plasma, adjusting the flux of ammonia gas, congealing solid nanometer powders, collecting congealed chromium nitride nanometer powders, packaging and the like. By the means of using the preparation method, chromium nitride nanometer powders with an average grain diameter of 40nm are obtained, wherein the size distribution of the chromium nitride nanometer powders is pretty narrow and the shape of the powders is spherical. The preparation method has the advantages of simple processing steps, a rapid burning rate, high reaction temperature, ease for controlling in the reaction process, no pollution and the like.

Description

technical field [0001] The invention relates to the field of nano-powder manufacturing, in particular to a method for preparing chromium nitride nano-powder. The method utilizes the high temperature of high-frequency induction plasma and the etching effect of plasma to realize chemical vapor phase synthesis to obtain superfine chromium nitride. powder. Background technique [0002] Nanopowders have different physical and chemical properties from ordinary materials, and show special properties in the fields of machinery, electromagnetism, light, heat, and chemistry, and are an important part of today's new materials. [0003] Chromium nitride (CrN) has good physical and mechanical properties, high hardness, good acid and alkali corrosion resistance, high chemical stability, good wear resistance, high melting point, etc. At the same time, chromium nitride is the only nitride with Antiferromagnetic materials. It is widely used in magnetism, electronics industry, high temperat...

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Problems solved by technology

[0007] 3. High-temperature self-propagating method: put loose-packed chromium powder with an average particle size of 2 microns into a graphite crucible, place it in a stainless steel airtight container, pump nitrogen into it after vacuuming and maintain a certain pressure, and then heat the resistance wire by electric current and ignite it Chromium powder, a point of chromium powder heated by resistance wire, once burned, the chemical reaction will continue to spread with the support of its own heat release, until the entire crucible, and the obtained product is Cr 2 N and CrN, the process and equipment of this method are simple, but there are also disadvantages that the finished product particles are too large, secondary crushing is required, and the combustion rate, reaction temperature, and reaction process are not easy to control.

If will contain Cr 2 S 3 The quartz tube is placed in a muffle furnace, fed with flowing ammonia, heated to 800°C and kept for 48 hours, then naturally cooled to obtain CrN powder, and its by-product is H 2 S, its disadvantage is that the reaction time is long and the finished product particles are large, H 2 S causes environmental pollution

Also Ammonolysis CrCl 3 , Ammonolysis of Cr 2 o 3 , Ammonolysis of urea chromium salt, etc., all require higher reaction temperature and longer reaction time, and are accompanied by the generation of pollutants

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