A kind of negative thermal expansion material sc2w4o15 and its solid phase sintering synthesis method

Abstract

The invention belongs to the technical field of inorganic non-metal materials and particularly discloses a negative thermal expansion material Sc2W4O15 and a solid-phase sintering synthesis method thereof. The method includes the steps that firstly, raw materials including Sc2O3 powder and WO3 powder are weighed according to the molar ratio of 1:4, mixed and evenly ground; secondly, the mixed material obtained in the first step is directly sintered or sintered after tabletting for the first time, and then quenching and drying are conducted; thirdly, the sample prepared in the second step is crushed, evenly ground and directly subjected to secondary sintering or subjected to secondary sintering after tabletting, then quenching and drying are conducted again, and the target product Sc2W4O15 is obtained. The negative thermal expansion material Sc2W4O15 has a stable negative thermal expansion property in the range of 176-1073 K, can emit yellow green fluorescence under excitation of ultraviolet, and has engineering application value. Two times of sintering are finished by means of the solid-phase sintering synthesis method, the reaction process is simple, sintering speed is high, reaction time is short, the raw materials react sufficiently at high temperature, and the prepared finished product is high in purity.

Description

technical field [0001] The invention belongs to the technical field of inorganic non-metallic materials, in particular to a negative thermal expansion material Sc 2 W 4 o 15 and its solid-phase sintering synthesis method. Background technique [0002] Most materials in nature have the characteristics of thermal expansion and cold contraction, but there is also an abnormal phenomenon of "thermal contraction and cold expansion" in nature, that is, negative thermal expansion. The difference in expansion coefficient between materials will cause device fatigue, performance degradation or even permanent failure. With the development of science and technology, people have more and more demand for materials with low expansion coefficient or zero expansion coefficient. People hope that by studying negative thermal expansion (NTE) materials, composite positive and negative expansion materials can be made into zero expansion or low expansion materials. the goal of. There are very ...

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Problems solved by technology

For example, commonly studied oxide negative thermal expansion materials include ZrW 2 o 8 This common AM 2 o 8 class material, but ZrW 2 o 8 It is a metastable phase material at room temperature, a phase transition occurs at about 150 °C, and it is easy to decompose when combined with other materials, etc., which seriously restricts its application.

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