Method for producing aluminium oxide ceramic composition containing novel four-component sintering additive

Abstract

The invention relates to a method for producing aluminium oxide ceramic composition containing novel four-component sintering additive. The method is characterized in that: the MO-CaO-SiO2-L2O3 additive is mixed in sintering precursor powder, wherein M is one of Mg, Ba and Be, L is a rare-earth element, and is one of Ce, La and Lu, and each substance accounts for 0.1 percent to 0.7 percent of theweight of the whole sintering additive. The particle size of the novel four-component sintering additive is less than 300 nanometers, while the particle size of aluminium oxide powder as matrix is measured in micron. The main materials, i.e. 75 percent to 90 percent by weight of carborundum powder, 5 percent to 20 percent by weight of four-component sintering additive and 1 percent to 5 percent by weight of bonding agent, are produced into sintered aluminium oxide ceramic compact by steps such as ultrasonic, sieving, shaping and high-temperature sintering. A liquid phase is formed, and is eliminated after spinel type substance with a melting point more than 2100 DEG C is gradually formed at the later stage of sintering, the substance can promote sintering, inhibit the growth of crystalline grains, promote the elimination of pores and increase high density, so that fine and uniform aluminium oxide ceramic crystalline grains and grain boundary porosity can be formed, and thereby the aluminium oxide ceramic material has good high-temperature mechanical and wear-resistant properties.

Description

technical field [0001] The invention relates to a method for producing alumina ceramics, in particular to a method for producing an alumina ceramic composition containing a sintering aid. Background technique [0002] Alumina ceramics have many advantages such as stable chemical properties, high mechanical strength, high hardness, high temperature resistance, good wear resistance, high electrical insulation capacity, oxidation resistance, good mechanical properties, rich raw material reserves, and low prices. It is an application field High-performance multi-purpose engineering ceramics with the widest usage, the largest amount, and great application development potential, widely used in various fields such as mechanical chemistry, electronics, aviation, and national defense [E. Medvedovski, Wear-resistant engineering ceramics, Wear, 249, 2001, 821 -828; Boutin P., Arthroplastie Totale de Hance par Prosthes en Alumine Fritte, Rev. Chir. Orthop., 1972, 58: 229-246.], known as...

AI Technical Summary

Problems solved by technology

However, liquid phase sintering also has many disadvantages. First, the liquid phase remains in the grain boundary as a glass phase, which reduces the high-temperature strength and wear resistance, and cannot meet certain high-temperature applications; secondly, it is easy to cause grain Abnormal growth [Edited by Suzuki Hiroshige, translated by Chen Shixing, Engineering Ceramics, Beijing: Science Press, 1989.] and hindering the further improvement of performance

Therefore, it is not enough to form small and uniform ceramic grains simply by forming a eutectic liquid phase to promote mass transfer and reduce the sintering temperature.