A kind of anti-high temperature oxidation film sensor and its production method

Abstract

The invention belongs to a high-temperature oxidation-resistant film sensor and a production method thereof. Its thin-film sensor includes an alloy substrate to be tested and a NiCrAlY alloy transition layer attached to its top surface. Above the transition layer is an alumina / aluminum nitride transition layer, an alumina / aluminum nitride ceramic insulating layer, and a sensor composed of electrodes. The functional layer and its Si3N4 isolation layer and the aluminum oxide protective layer arranged on the isolation layer; its production method includes surface treatment of the alloy substrate, deposition of a NiCrAlY alloy transition layer on the alloy substrate, precipitation of metal aluminum, oxidation or nitriding treatment, The Al2O3 / AlN ceramic insulating layer is set, the thin film sensor functional layer and its Si3N4 isolation layer are set, and the Al2O3 protective layer is set. The Si3N4 isolation layer set in this invention can effectively prevent the oxygen atoms decomposed from the insulating layer and the aluminum oxide protective layer from diffusing to the functional layer, and improve the stability and reliability of the sensor in high temperature and high pressure working environment. The research and design of turbine engines provide corresponding and more accurate basic data.

Description

Technical field [0001] The invention belongs to the technical field of thin film sensor design and production, in particular, it uses alloy materials such as turbine engine blades and combustion chamber walls to be tested as substrates, and is directly installed on the surfaces of the turbine engine blades and combustion chamber walls to be tested to resist high temperature oxidation. The thin film sensor method can be widely used to measure the temperature, strain and other state parameters of the surface of structural parts such as turbine engine blades and combustion chamber walls, and provide more accurate basic data for the research and design of turbine engines. Background technique [0002] When modern aero-engines are working, because the turbine blades and combustion chamber are in high temperature, high pressure and other harsh environments caused by gas combustion, the surface temperature of the turbine blades and combustion chamber rises sharply, and at the same time, ...

AI Technical Summary

Problems solved by technology

However, this kind of thin film sensor has the following defects in its work: in high temperature environment, Al 2 o 3 Ceramic insulating layer and Al 2 o 3 Al in protective layer 2 o 3 It will decompose and generate oxygen atoms, so that the functional layer of the thin film sensor is in an oxidizing environment; while the common thin film sensor functional layer materials are very sensitive to oxidation, such as common thin film thermocouple functional layer materials, ITO (indium tin oxide) thermoelectric Take even thin film as an example, ITO thin film is an n-type semiconductor, and the carriers mainly come from the donor Sn 4+ Substitution of In in Indium Oxide 3+ One electron released and two electrons released by the oxygen vacancies of indium oxide in the reduced state, and when the ITO film is oxidized, the oxygen vacancies existing in the ITO film will also be filled by oxygen atoms, making the resistance of the ITO film The rate rises sharply, the carrier concentration decreases, and the conductivity deteriorates, which seriously affects important parameters such as the Seebeck coefficient of the thin-film thermocouple; among the common thin-film strain gauge functional layer materials, NiCr material in the metal thin film is taken as an example, its conductivity The mechanism is that the valence electrons are not bound by atoms and move freely in the metal. When some metal atoms combine with oxygen to form oxides, the conductivity will become poor and will affect the TCR (temperature coefficient of resistance) of the thin film strain gauge to a certain extent. ) and GF factor (gauge factor)

[0004] In the patent document with the publication number CN102212823A, the "Method of Setting a Thin Film Sensor on an Alloy Substrate" is disclosed. After a certain thickness of aluminum (Al) is deposited in the NiCrAlY transition layer, the method of the invention is directly sputtered by magnetron sputtering. Sputtering a layer of metal aluminum (Al), so that the sputtered layer of metal aluminum (Al) and the precipitated aluminum (Al) are fused into one, and evenly distributed on the surface of the NiCrAlY transition layer, and then the metal aluminum (Al) layer Oxidation treatment to generate Al 2 o 3 Connect the transition layer, and then in the Al 2 o 3 Preparation of Al on the connecting transition layer 2 o 3 Ceramic insulating layer, thin film sensor functional layer and Al 2 o 3 Protective layer; the thickness of the NiCrAlY transition layer in this method is reduced from the traditional 100 μm to about 5 μm in this invention, which greatly reduces the difficulty and cost of preparing the NiCrAlY transition layer, and at the same time effectively improves the thin film sensor in the 1000 ° C environment. Safety and reliability; with thin NiCrAlY transition layer, and Al 2 o 3 The advantages of high connection strength of the ceramic insulating layer; but the use of Al 2 o 3 Ceramic insulating layer, thin film functional layer, Al 2 o 3 The traditional structure of the protective layer is very easy to cause Al 2 o 3 insulating layer and Al 2 o 3 Al in protective film 2 o 3 Oxygen atoms produced by decomposition diffuse into the functional layer, resulting in the oxidation of the functional layer at high temperature, which affects the performance of the thin film sensor

[0005] "A metal-based thin-film thermocouple and its production method" is disclosed in the patent document with the publication number CN101894904A. This invention is based on the traditional process of depositing multi-layer composite thin films on the metal substrate, and adopts high thermal conductivity and excellent insulation performance. The AlN ceramic insulating layer to replace the Al in the traditional metal-based thin film thermocouple process 2 o 3 Ceramic insulating layer, thereby reducing the temperature difference between the metal substrate and the surface of the insulating layer and the thickness of the insulating layer, and can effectively reduce the measurement error, improve the consistency and reliability of the temperature measured by the thermocouple and the actual temperature of the metal substrate to be measured; but Thanks Al 2 o 3 The protective layer is easy to decompose and produce oxygen atoms in the high temperature environment, which will oxidize the functional layer of the thin film sensor and affect the performance of the thin film sensor.

[0006] To sum up, in the current preparation of metal-based thin-film sensors, no matter using the traditional technology or the two patented technologies with publication numbers CN102212823A and CN101894904A, the functional layer of the thin-film sensor is easily oxidized in a high-temperature environment, which affects its performance and work. Time stability, reliability and measurement accuracy and other defects

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