Preparing method for micron cBN particles wrapped by nano SiO2 film

The invention discloses a preparing method for micron cBN particles wrapped by a nano SiO2 film, and belongs to the technical field of materials. The preparing method comprises the steps of (1) proportionally preparing liquid A comprising TEOS and ethyl alcohol, liquid B comprising ammonia water, water and ethyl alcohol, and liquid C comprising ethyl alcohol and cBN powder; (2) ultrasonically sealing the liquid C, dispersing the liquid C, immediately placing the liquid C into a water bath kettle, and stirring a water bath; (3) dropwise adding the liquid A and the liquid B into the liquid C, and stirring the water bath; (4) enabling the dispersing agent obtained by a complete reaction to stand or centrifuging the dispersing agent, and obtaining the wrapped micron cBN particles and colloidal soil; (5) drying the wrapped micron cBN particles in a drying oven after the wrapped micron cBN particles are cleaned with ethyl alcohol, and obtaining the micron cBN particles wrapped by the nano SiO2 layer. According to the preparing method, the problem that lifting packaging, suspension packaging and PVD and CVD packaging are difficultly carried out on the cBN particles is solved, the wrapped particles can keep the original dispersity, the impurity of powder obtained after wrapping is high, the quantity of impurities is small, the wrapping time and the thickness of the wrapping layer are controllable, equipment is simple, the cost is low, and operation is easy.