A kind of glass-ceramic whose main crystal phase is lanthanum disilicate and its preparation method and application

Abstract

The invention relates to ceramic glass with lanthanum disilicate as a principal crystalline phase, a preparation method and application. The ceramic glass is obtained by carrying out nucleation and crystallization treatment on base glass. The base glass consists of the following oxides in mole percent: 22-26% of La2O3, 3-5% of MgO, 11-13% of Al2O3 and 58-62% of SiO2. The preparation method comprises the following steps: melting the various raw materials at the temperature of 1,520-1,530 DEG C; pouring melted liquid in a mold and annealing at the temperature of 650-680 DEG C to obtain the base glass; heating the base glass until the temperature of the base glass is higher than glass conversion temperature which is 40-60 DEG C, carrying out nucleation, and continuing heating to the temperature which is equal to devitrification temperature + / - 10 DEG C to obtain a ceramic glass material. The preparation method is simple, energy consumption is low, the ceramic glass is environmentally friendly, the production cost is low, and the obtained material can be used as a thermal barrier coating material, a high-temperature-structure material, an anti-friction and anti-abrasion material and the like.

Description

technical field [0001] The invention belongs to the field of material science, and relates to a glass-ceramic whose main crystal phase is lanthanum disilicate, a preparation method and application thereof. Background technique [0002] La 2 o 3 -SiO 2 Common compounds in binary systems are lanthanum orthosilicate (La 2 SiO 5 ), phospholime lanthanum silicate (La 9.33 (SiO 4 ) 6 o 2 ) and lanthanum disilicate (La 2 Si 2 o 7 )Wait. Among them, lanthanum disilicate has two crystal forms, one is a tetragonal crystal phase formed at low temperature, and the other is a monoclinic crystal phase formed at high temperature, and its high-temperature monoclinic crystal has excellent comprehensive properties. For example, it has low thermal expansion coefficient, low thermal conductivity, excellent thermal corrosion resistance and friction and wear resistance, and it has good high temperature performance, such as good high temperature oxidation resistance, excellent high tem...

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Problems solved by technology

Lanthanum disilicate ceramics have high crystal phase content, excellent chemical stability and mechanical properties, and good high temperature performance, but their sintering needs to be carried out under high temperature conditions by hot pressing sintering (sintering of lanthanum disilicate ceramics The temperature is as high as 1700-1800°C), the preparation is very difficult, and there are pores and grain boundaries in the ceramics

However, there are few reports on the technology of glass-ceramics whose main crystal phase is lanthanum disilicate

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