Auxiliary heat insulation device for microwave sintering

Abstract

The invention belongs to the field of microwave sintering, and particularly relates to an auxiliary heat insulation device for microwave sintering. The device sequentially comprises a polycrystallinemullite high-temperature fiber cotton layer, a mullite fiber box and a boron nitride crucible from outside to inside, wherein fiber cotton fills the space between the crucible and the mullite fiber box; the outer layer of the mullite fiber box is wrapped with the polycrystalline mullite high-temperature fiber cotton layer; a temperature measuring hole is formed in the center of an upper cover plate of the mullite fiber box; the boron nitride crucible comprises a crucible main body and a crucible cover, a boron nitride ring is arranged in the crucible main body, a gap between the boron nitridering and the boron nitride crucible and the interior of the boron nitride ring are filled with silicon nitride powder, and a sintered sample is arranged in the center of the boron nitride ring and isembedded in the silicon nitride powder for sintering; and the center of the crucible cover is provided with an inverted funnel-shaped through hole. Based on the wave-absorbing and wave-transparent performance of different materials in the device, the device can play excellent heat insulation and auxiliary heating roles in microwave sintering; and the funnel-shaped temperature measuring hole of thecrucible cover is favorable for heat insulation and discharging volatilized glue in the sintering process of the sample.

Description

technical field [0001] The invention belongs to the field of microwave sintering, and in particular relates to an auxiliary heat preservation device for microwave sintering. Background technique [0002] Microwave sintering is a sintering method introduced in the 1970s. Its biggest feature is to use microwave energy to heat the sintered material as a whole. Because of the overall heating, the material is heated evenly and the temperature gradient is small. The properties of the sintered material are uniform and crystallized. The particles are small and compact. In addition, microwave sintering also has the characteristics of high efficiency, energy saving, and environmental protection, and can achieve structures and properties that cannot be achieved by traditional sintering methods. However, the sintering temperature of some materials (such as ceramic materials) is high, and the microwave absorption performance is poor at low temperatures. Therefore, the design of the ther...

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Problems solved by technology

However, in this device, the area between the crucible and the bottom insulation brick is filled with insulation cotton. During the sintering process, the surrounding temperature of the crucible is relatively high. After several times of use, the local high temperature of the crucible will soften the surrounding insulation cotton, causing the crucible to collapse and affecting the sintering process. , and all insulation cotton needs to be replaced before it can be used again, and the replacement cost is high

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