Fe-based multi-component active high-temperature solder for carbon fiber-reinforced ceramic matrix composites

Abstract

The invention designs an Fe-based multi-element active high-temperature brazing filler metal for carbon fiber-reinforced ceramic-matrix composite materials. Mainly use low-expansion coefficient stainless steel as the master alloy without adding melting elements. During brazing, the liquid phase is obtained by eutectic reaction between Fe in the brazing material and carbon fiber, which can quickly wet non-metallic carbon fiber and is conducive to improving The melting point of the brazing material, the brazing temperature and the service temperature of the joint are also beneficial to avoid brittle intermetallic compounds formed by demelting elements; because the stainless steel master alloy and the added refractory element Mo have the advantages of small thermal expansion coefficient and high thermal strength , so the obtained brazing joint has the advantages of small thermal expansion coefficient, oxidation corrosion resistance, and high thermal strength, which is beneficial to reduce thermal stress and increase the service temperature of the joint, and improve the overall performance of the joint; High, fast wetting response, short holding time, high room / high temperature strength of brazed joints.

Description

technical field [0001] The invention relates to CMC high-temperature solder, in particular to a CMC high-temperature solder f / SiC and other carbon fibers (C f ) Fe-based multi-component active high-temperature solder for reinforced ceramic matrix composites. Background technique [0002] The continuous fiber reinforced ceramic matrix composite (CMC: ceramic matrix composite) obtained by implanting a continuous fiber reinforced phase in the ceramic matrix combines the advantages of carbon fiber (high specific strength, high specific modulus, excellent high temperature mechanical properties) and thermal properties) and the advantages of SiC ceramics (high hardness, strong corrosion resistance, strong oxidation resistance), it has become a relatively safe and practical method to improve the strength and toughness of ceramics. During the load-bearing fracture process of ceramic matrix composites, the external force or energy absorption can be balanced by mechanisms such as cr...

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Problems solved by technology

[0045] For carbon fiber-reinforced ceramic matrix composite base materials, the purpose of the present invention is to break through the existing Ag-based (such as Ag-Cu-Ti), Ti-based (such as Ti-Ni-Cu) solder with low melting point and poor heat resistance of the brazing seam. (The melting point is about 780-950°C), the primary technical problem, and the secondary problems of slow wetting of carbon fibers and too long holding time (such as Ni-based solder must be held for a long time to achieve isothermal solidification to increase the remelting temperature of the joint) , to design a melting element that does not contain de-melting elements (no Fe, Ni, Cr, Mo, to increase the melting point of the solder, forcing the solder to melt into a liquid phase only through the eutectic reaction with carbon fibers, and the joint The brazing temperature and remelting temperature are increased to Fe-C f The eutectic reaction temperature is 1154°C, and avoids brittle intermetallic compounds formed by melting elements), using cheap Fe as matrix element and active element (using Fe-C f The eutectic reaction realizes the wet carbon fiber, so Fe is the active element that wets the carbon fiber reinforced phase) Fe-based multi-active high-temperature solder (the basic alloy system is five-element Fe-Cr-Ni-Mo-Ti, Fe-Cr-Ni -W-Ti, etc. or six-element Fe-Cr-Ni-Mo-W-Ti, etc.)

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