Method for preparing ZrC coating

Abstract

The invention discloses a method for preparing a ZrC coating. The method comprises the following steps: (1) surface processing of a base material; (2) sample arrangement: respectively putting the base material and metal zirconium in a deposit zone and a halogenating reaction zone of a chemical vapor deposition furnace; (3) system temperature rise, raising the temperature of the deposit zone to the deposit temperature, and raising the temperature of the halogenating reaction zone to the halogenating reaction temperature; and (4) preparation of the ZrC coating: introducing an H2 steady air flow to the chemical vapor deposition furnace, introducing Br2 steam into the halogenating reaction zone through a carrier gas Ar to generate an in situ halogenating reaction with the metal zirconium to produce a zirconium source precursor ZrBr4 steam, introducing a carbon source gas to the furnace and depositing on the surface of the base material of the deposit zone to obtain the ZrC coating. The preparation method provided by the invention is simple in process, low in cost, convenient to operate and wide in application scope, the use amount of the zirconium source precursor can be precisely controlled and the prepared ZrC coating is close to the stoichiometric ratio.

Description

technical field [0001] The invention belongs to the field of material preparation, and relates to a method for preparing a ZrC coating, in particular to a method for preparing a ZrC ultra-high temperature coating by chemical vapor deposition, which is suitable for carbon / carbon composite materials, carbon / ceramic composite materials, graphite, carbonization Surface coating and thermal protection of materials such as ceramics. Background technique [0002] The new generation of hypersonic vehicles that serve in extreme environments such as long-term flight, reentry, transatmospheric flight, and rocket propulsion systems have put forward urgent requirements for ultra-high temperature and ablation-resistant structural materials. need. Among the existing high-temperature structural materials, high-purity graphite, C / C, C / SiC composite materials and ultra-high temperature resistant ceramics and their composite materials have low density, high strength, high toughness, chemical c...

AI Technical Summary

Problems solved by technology

At present, the commonly used zirconium source output form is complicated in equipment, low in raw material utilization, high in cost, and poor in repeatability. For example, in the direct evaporation zirconium halide method, by controlling ZrCl 4 The heating temperature and carrier gas flow to control the ZrCl 4 The dosage, due to the ZrCl 4 Sublimation can only be done at 331°C, so it is easy to condense in the pipeline, the operability is poor, and the dosage control is not accurate; ZrCl is used 4 In the solid blanking mode, the powder is easy to condense and adhere to the furnace wall during the process of converting into steam in the furnace, resulting in a large amount of raw materials, high production costs, and unstable control of the zirconium source; a spiral powder feeder is used, and an evaporation tank is added. In this way, although the stable supply of zirconium source can be realized, the equipment is complicated, and the pipeline needs to be equipped with heat preservation measures above 400 ° C. Due to the ZrCl 4 Strong corrosion, high temperature sealing performance requirements for equipment

In addition, ZrCl 4 It is easy to deliquesce in the air, difficult to store raw materials, and easy to be polluted during transfer

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