Preparation method of superfine boron carbide spray granulation powder

Abstract

The invention belongs to the field of nano material processing and discloses a preparation method of superfine boron carbide spray granulation powder. The preparation method includes: using compressed air to well mix boron carbide powder not larger than 500um, deionized water and sodium polycarboxylate, and grinding paste to 0.4-0.5um in granularity; enabling obtained paste to pass a 500-mesh sieve, using 'tu-4 cup' to measure and strip-pasting to 100S, sequentially adding polyethylene glycol 6000 water solution and hydrogen peroxide, and feeding compressed air for well mixing; pumping obtained paste into a centrifugal spray granulator which is already preheated through a peristaltic pump for granulation drying to obtain spray granulation powder; detecting and aging for 48h, and subjecting to boron carbide ceramic sintering to obtain the superfine boron carbide spray granulation powder. Other grading processes do not need to be adopted, one drying process is omitted, production period is short, and energy consumption is low; the superfine boron carbide spray granulation powder creates a condition for non-pressure sintering of boron carbide ceramic.

Description

technical field [0001] The invention belongs to the field of nano material processing and discloses a preparation method of ultrafine boron carbide spray granulation powder. Background technique [0002] Due to the excellent characteristics of boron carbide (high hardness, low density, acid and alkali resistance, etc.) [refer to EVANS A.GPerspective on the Development of High Toughness ceramics [J] J.AM ceram SOC1990.73(2): 186-193], The demand for boron carbide ceramic products is increasing, but the prerequisite for the production of high-quality boron carbide ceramics is high-quality boron carbide powder, so the production of high-quality ultra-fine boron carbide powder has become the first development of boron carbide ceramics A top priority [Tang Lidan, Mu Baichun, Zhang Hui Factors affecting the densification of boron carbide ceramics [J] Journal of Liaoning Institute of Technology. 2005.378:381-6]. [0003] At present, the raw material used to produce boron carbide ...

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Problems solved by technology

[0004] (1) A large amount of iron is brought into the ball milling process, so it must be purified by pickling process, which not only increases the cost of discharged wastewater but also pollutes the environment

[0005] (2) Due to the low density of boron carbide, the settling time is too long when classifying finer powders. The most important thing is that the particles with a particle size of less than 1 micron will be in an unfavorable position when the effect of water molecules is small. The state of precipitation has caused great difficulties to the collection. Some people use ethanol as the fluid medium for sorting, but the cost is too high, the risk of fire is high, it is toxic to the operator and pollutes the environment, so it cannot be used in large-scale production

[0006] (3) The finer boron carbide powder will harden after drying, making it difficult to loosen, and certain impurities will be brought in during crushing

[0007] (4) The material has low natural bulk ratio, poor stability, large particle size, and relatively harsh sintering conditions, which are not conducive to the production of high-grade boron carbide ceramic products [Du Xianwu, Zhang Zhixiao, Wang Weimin, Fu Zhengyi, Wang Hao, powder particle size, hot-pressed sintered boron carbide density Influence of protection and mechanical properties[J]Journal of Inorganic Materials

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