Aerospace Key Components Integrated Thin Film Thermal Resistance Sensor

In the aerospace industry,in order to avoid large-scale accidents and losses,it is necessary to strictly control and test the working temperature of various parts.In order to further understand and study the temperature changes during the use of aviation components,thin-film temperature resistors stand out from traditional temperature resistors.Compared with traditional temperature resistors,thin film temperature resistors have many advantages that cannot be ignored.Thin-film micrometer or even nanometer thickness structures do not occupy the space of components.And different sensor structures can be designed according to the shape of different devices.This sensor structure is flexible and can be applied to various shapes of devices.The direct growth form of the film on the component results in the rapid heat transfer and the minimum heat loss of the component,which can accurately measure the real temperature of the component to a large extent.In practical applications,the materials of most parts will deform and crack at high temperature,thus losing normal working ability and causing functional failure.Therefore,it is essential to prepare the thermal resistance of the film through the low temperature preparation process and measure it at the normal or low temperature stage.In this study,on the one hand,electron beam evaporation was used to prepare an insulating layer with better insulation;on the other hand,the process of preparing the thermal resistance of the Ni thin film at low temperature was studied by DC magnetron sputtering.The experiment is divided into three steps for research:Firstly,the alumina insulating layer is prepared on the bearing surface by electron beam evaporation.This paper mainly studies the insulation layer with different thickness and structure,and finally achieves the goal of complete electrical insulation between the bearing and the functional layer film.We have found that an insulating layer prepared multiple times by using the same insulating material has better insulation and adhesion than an insulating layer prepared once.Secondly,the DC magnetron sputtering method was used to prepare the functional layer film.The process of low-temperature film thermal resistance was discussed,and the effects of different substrate temperatures,deposition pressure and sputtering power on the film were also discussed.Finally,we determined that a process with a normal temperature of 0.3 Pa and a power of 60 W is the most suitable.It can stabilize the TCR of the film at 3000 ppm / ° C,and conduct a series of tests under these conditions.Finally,prepare the insulating layer and the functional layer on the bearing in sequence,and test the entire bearing.On the one hand,the TCR test is performed in the temperature range of 200 ° C to study its linearity and repeatability.The TCR value on the bearing can reach 2000 ppm / ?,with better repeatability and better linearity;on the other hand,according to the working environment of the bearing,the adhesion of the prepared bearing was tested to ensure that the working environment of the bearing will not affect the performance of the functional layer.