Tungsten/silicon nitride/tungsten symmetrical laminated gradient composite material as well as rapid preparation method and application thereof

Abstract

The invention discloses a W / Si3N4 / W symmetrical laminated gradient composite material as well as a rapid preparation method and an application thereof, and belongs to the technical field of preparation for ceramic matrix composite materials. According to the tungsten / silicon nitride / tungsten symmetrical laminated gradient composite material as well as the rapid preparation method and the application thereof, the W / Si3N4 / W symmetrical laminated gradient composite material is prepared through an SPS sintering technology; in the method, an electric field is further introduced on the basis of a temperature field and a pressure field, a plasma activation effect on raw materials can be acted, so that a compact composite ceramic material can be rapidly prepared under the conditions of a low sintering temperature and a short heat-insulation time; and meanwhile, the activation effect of plasmas also contributes to the diffusion of atoms, then the interlayer bonding of W and Si3N4 can be promoted, and the high-performance connection between W and Si3N4 is realized. The method has the advantages of being high in heating speed, low in sintering temperature and short in heat-insulation time, and the W / Si3N4 / W symmetrical laminated gradient composite material with high compactness, low impurity content and good interface bonding can be rapidly prepared via the method.

Description

technical field [0001] The invention belongs to the technical field of preparation of ceramic matrix composite materials, in particular to a W / Si 3 N 4 / W Symmetric layered gradient composite materials and their rapid preparation methods and applications. Background technique [0002] Silicon nitride (Si 3 N 4 ) Ceramics have excellent mechanical properties and chemical stability such as high temperature resistance, good thermal shock resistance, high insulation coefficient, high wear resistance, and corrosion resistance. Therefore, they are used in high-temperature structural materials, refractory materials, insulating materials and corrosion-resistant materials. There are broad application prospects in the field. In practical applications, Si is usually required 3 N 4 Combined with metal components such as heat-resistant alloys or stainless steel. And the thermal expansion coefficient of alloy or stainless steel (10~16×10 -6 / ℃) is much larger than that of Si 3 N ...

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Problems solved by technology

But this method also has some disadvantages: first, the automatic grouting molding equipment of this method is complex and expensive, and the lamination process is difficult to realize; second, the sintering process has a high sintering temperature, a long holding time, and requires Third, some elements will segregate on the interface of the sample sintered by this method, resulting in stress concentration and easy formation of defects such as interface cracks, which directly affect the mechanics, physics, chemistry and electricity of the material. Chemical properties; Fourth, due to the addition of some polymer dispersants during automatic grouting, large pores appeared in the middle layer of the sample after sintering, resulting in problems such as low strength and poor air tightness

Therefore, the ceramic / metal gradient materials obtained by the existing preparation methods are still difficult to be used as long-term high-temperature insulating packaging materials for liquid metal batteries, and some structural / functional integrated components.

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