Preparation method of boron nitride nanotube-intensified silicon oxide ceramic

Abstract

The invention relates to a preparation method of a boron nitride nanotube-intensified silicon oxide ceramic, which comprises the following steps of: A. pre-treating boron nitride nanotubes; B. weighing the boron nitride nanotubes and nano-grade and micron-grade silicon oxides; C. treating with different surface active agents; D. adding to a ball-milling pot, and compounding; E. drying, and screening; F. carrying out the hot pressed sintering in a multifunctional high-temperature sintering furnace in the shielding gas atmosphere; G. maintaining the temperature, then stopping heating, and naturally cooling to the room temperature; and H. machining the sintered ceramic block, and then testing the performance. The invention is a method which effectively improves the mechanical property of the silicon oxide, and greatly improves the mechanical property of the silicon oxide. The bend strength of the boron nitride nanotube-intensified silicon oxide ceramic is up to 130MPa, and is 6.5 times higher than that of the pure silicon oxide ceramic (19.6MPa).The process improves the mechanical property of the silicon oxide ceramic, and has the advantages of simple process, stability, high safety, easy operation and large scale production.

Description

[0001] technical field [0002] The invention relates to a method for preparing silicon dioxide ceramics, in particular to a method for preparing silicon dioxide ceramics reinforced with boron nitride nanotubes. Background technique [0003] Boron nitride nanotubes are energetically stable, have a constant wide energy gap (about 5.5eV), have high chemical stability and oxidation resistance, and the energy gap does not change with the change of chirality and tube layer number , and its oxidation temperature is as high as 900°C. These advantages make it widely used in high temperature, high-strength fibers, semiconductor materials, etc., especially in the strengthening and toughening of ceramic materials. [0004] Common ceramic toughening methods include: phase transformation toughening, whisker and particle toughening, fiber toughening, nanowire and nanotube toughening, and the like. However, the effect of phase transformation, whisker and particle toughening is not partic...

AI Technical Summary

Problems solved by technology

However, the effect of phase transformation, whisker and particle toughening is not particularly obvious; the operation engineering of fiber toughening is more complicated, not easy to operate, and the product density is poor; at present, many people use carbon nanotubes to toughen ceramics, but carbon The high-temperature oxidation of nanotubes and the easy reaction with matrix materials at high temperatures limit its application.

[0005] The traditional mixing process of ceramics is difficult to ensure uniform dispersion, which makes the performance of ceramics unstable, and the repeatability of the experimental conclusions is poor. Using surfactants to disperse materials can make boron nitride nanotubes more uniformly dispersed, and silica powder The body is not easy to agglomerate, so that the various properties of ceramics are more stable

[0006] The application number is 200910015758.1, which discloses the following technology in the Chinese patent application. The preparation method includes weighing raw materials, ball milling, sintering, heat preservation and cooling, and preparing finished products. However, the ball milling process uses a dry mixing process, and the uniformity of the mixed powder is relatively poor. Affect the quality of the product; no protective atmosphere is used in the sintering process, which affects the quality of the product; and in the process of preparing the finished product, the efficiency is low and the quality is poor

Images