C/C composite material surface carbide derived carbon/rhenium/iridium coating layer and preparation method thereof

Abstract

The invention discloses a C / C composite material surface carbide derived carbon / rhenium / iridium coating layer and a preparation method thereof. The coating layer takes a C / C composite material as a matrix; a carbide-derived carbon layer, a rhenium coating layer and an iridium coating layer are sequentially arranged on the surface of the C / C composite material from bottom to top. The preparation method comprises the steps: preparing a pure Si layer on the C / C composite material matrix, carrying out heat treatment to obtain an SiC layer, carrying out chlorine etching to form the carbide-derivedcarbon layer, and sequentially depositing the rhenium coating layer and the iridium coating layer on the carbide-derived carbon layer. The carbide-derived carbon / rhenium / iridium coating layer can perfectly consider coating layer combination, coating layer matrix thermal mismatch alleviation and coating layer system high-temperature thermochemical compatibility, and has a wide application prospect.

Description

technical field [0001] The invention belongs to the technical field of high-temperature materials, and relates to an ultra-high temperature oxidation-resistant coating system and a preparation method thereof, in particular to the structure of a carbide-derived carbon / rhenium / iridium (CDC-C / Re / Ir) coating on the surface of a C / C composite material Design and method of preparation. Background technique [0002] The carbon / carbon composite material (C / C composite material) with carbon fiber as the reinforcing phase and carbon as the matrix has a series of excellent properties such as low density, low thermal expansion, high specific strength ratio modulus, thermal shock resistance and creep resistance, especially It is the characteristic that the strength increases with the increase of temperature in an inert environment of 1000-2300 ° C. It has been closely concerned by researchers and is widely used in solid rocket motor nozzles and throat linings, thermal protection systems ...

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Problems solved by technology

Chen Zhaofeng et al. prepared a W transition layer between the C / C composite material and the Ir coating, which improved the combination of Ir and the C / C composite material, but due to the formation of brittle compounds between W, C and Ir at high temperatures, resulting in its Insufficient thermal shock resistance at high temperature; Pemsler et al. first treated the surface of the C / C composite material to selectively oxidize the carbon matrix on the surface, leaving only carbon fibers, and then prepared the Ir coating to form a C fiber-reinforced Ir coating structure , this coating structure significantly enhanced the bonding between Ir and C / C composites, but still could not overcome the coating cracking caused by thermal expansion mismatch; Mumtaz et al. first deposited pyrolytic carbon on the surface of C / C composites As a transition layer, it enhances the combination of the Ir coating and the substrate and uses the thermal expansion coefficient of the pyrolytic carbon to relieve the thermal mismatch to a certain extent. The difference is too large and the brittleness of the pyrolytic carbon layer itself, the problem of cracking still exists; considering that Re has good thermochemical compatibility with Ir and C (no low melting point phase or brittle compound is formed at high temperature), Huang Yongle et al. Re is used as a transition layer, and Co is used as an alloying modifying element at the same time. Through alloying, the plasticity of Re near the crack is improved, and the crack on the Re surface is repaired, and a crack-free Ir coating is prepared. However, this method introduces low The Co element at the melting point reduces the service temperature of the coating system to a certain extent, especially in cracks with high Co content, there is a risk of melting when used at high temperatures

These studies have played a certain role in coating bonding or coating-matrix thermal expansion transition, but none of them can perfectly take into account coating bonding, coating-matrix thermal mismatch mitigation, and high-temperature thermochemical compatibility of the coating system (such as forming at high temperature). Brittle compounds, low melting point substances, etc.)

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