Negative heat expansion coefficient material quick sintering synthesizing method

Abstract

The rapid sintering synthesis method of materials with negative thermal expansion coefficients is to sinter the raw materials that can generate negative thermal expansion coefficient materials in a high-temperature furnace, so that they can quickly react to form negative thermal expansion coefficient materials. The material with negative thermal expansion coefficient is Hf(WO4)2, the raw materials used are HfO2 and WO3, the molar ratio of HfO2 to WO3 is 1:2-2.2; the sintering temperature is 1300°C-1460°C, and the sintering time is 5 minutes to 300 minutes . The negative thermal expansion coefficient material is Hf(MoO4)2, the raw materials used are HfO2 and MoO3, the molar ratio of HfO2 and MoO3 is 1:2-2.2; the sintering temperature is 800°C-1150°C, and the sintering time is 5 minutes to 300 minutes . The material with negative thermal expansion coefficient is Zr(MoO4)2, the raw materials used are ZrO2 and MoO3, the molar ratio of ZrO2 and MoO3 is 1:2-2.2; the sintering temperature is 900°C-1200°C, and the sintering time is 5 minutes to 120 minutes . The invention has high synthesis speed, low energy consumption, no pollution, high purity and is suitable for large-scale production.

Description

technical field [0001] The invention belongs to the technical field of material synthesis, and in particular relates to a rapid sintering synthesis method of negative thermal expansion coefficient materials. Background technique [0002] The rapid sintering synthetic material technology uses a high-temperature sintering furnace as a heating source, and the raw material components react at high temperature in the sintering furnace to form new materials. Most materials have the property of thermal expansion and contraction, and the thermal stress (or thermal shock wave) generated by thermal expansion and contraction is often the main reason for device fatigue, performance degradation, failure or even fracture and shedding. In the field of aerospace, both functional and structural materials are faced with the severe test of thermal stress (or thermal shock wave). When a spacecraft is in space, it is irradiated by the sun, and the temperature difference between its dark and sunn...

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Problems solved by technology

[0004] From the above, it can be seen that the traditional solid state reaction method takes a long time to sinter at high temperature and consumes a lot of energy. The sample preparation time generally takes a few days to about a week, and the total time is long.

Long time sintering causes WO 3 and MO 3 The large amount of volatilization is another shortcoming of the traditional solid state reaction method

However, the liquid phase synthesis method mostly uses salt compounds as raw materials and reacts in solvents (often need to add acid reagents). The preparation process is complicated and time-consuming, and the prepared precursor still needs to be sintered at high temperature.

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