Silicon nitride ceramic piece and processing method thereof

Abstract

The invention discloses a silicon nitride ceramic part and a processing method thereof. The silicon nitride ceramic part comprises a first cylinder, and two ends of the first cylinder are respectively provided with a first end face and a second end face; a first fixing seat is arranged in the first cylinder body, and the first fixing seat is connected with the first end face in a penetrating manner; a second fixing base is arranged on the upper surface of the second end face and connected with the second end face in a penetrating mode. The preparation method of the silicon nitride ceramic part comprises the following steps: granulating, carrying out cold isostatic pressing molding to obtain a primary green body, carrying out finish machining to obtain a second green body, pre-sintering to obtain a third green body, and finally sintering to obtain the silicon nitride ceramic part. The silicon nitride ceramic piece is uniform in internal density distribution, high in strength, low in density, large in size, easy to process and high in finished product percent of pass.

Description

technical field [0001] The invention relates to the field of processing silicon nitride ceramic parts, in particular to a processing method of a silicon nitride ceramic grading wheel. Background technique [0002] In order to meet the development of information technology, biotechnology and new material technology, higher requirements are put forward for the purity and particle size distribution of powder products. With the development of crushing technology, air classifiers are constantly updated. The classifying wheel is a key part of the air classifier, which affects the fineness and purity of the crushed powder. [0003] Traditional classification wheels are mainly made of stainless steel, alumina, zirconia and other materials. During the crushing process, due to the high density of the material, the classification wheel requires high energy consumption to achieve high-speed rotation. High content of impurities; [0004] The density of traditional materials is high, a...

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Problems solved by technology

[0003] The traditional classifying wheel is mainly made of stainless steel, alumina, zirconia and other materials. During the crushing process, due to the high density of the material, the classifying wheel requires high energy consumption to achieve high-speed rotation. High content of impurities;

[0004] The density of traditional materials is high, and the density of stainless steel is 7.6g / cm 3 , alumina density 3.9g / cm 3 , zirconia density 6.1g / cm 3 , seriously affects the speed increase of the classifying wheel, and then affects the fineness of the classifying powder, which cannot meet the high-purity and ultra-fine requirements of the country in the high-tech field for material performance;

[0005] Silicon nitride ceramics have excellent properties such as low density, high bending strength, high toughness and high hardness. However, due to the high hardness of silicon nitride ceramics, it is difficult to process the finished product, and it is easy to appear in the green body during sintering. The volatilization of solvent or organic matter causes high porosity, which leads to a decrease in the strength of silicon nitride ceramics after sintering and uneven density distribution inside the ceramics, resulting in uniform density distribution inside the material, resulting in polarization and grading wheels appearing when the silicon nitride grading wheel rotates at high speed. serious wear or damage;

[0006] At the same time, problems such as deformation or size change are prone to occur when the green body is sintered;

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