Preparation Of Silica Film From Soft Magnetic Alloy Substrate And Its Performance Research

Magnetohydrodynamics(MHD)micro-angle vibration sensor is a new type of instrument that can achieve micro-angle vibration and sub-micro-radian measurement.It has the characteristics of low noise,wide frequency band,high precision,and impact resistance.It is mainly used in the space environment.Micro-angle vibration measurement and micro-radian measurement.The working principle of the MHD micro-angle vibration sensor is to use a conductive fluid to vibrate in a magnetic field to generate an induced electromotive force to sensitive vibration information.Normal structural design: the upper and lower surfaces of the cavity of the conductive fluid are made of insulating material,the inner and outer electrodes are made of conductive material,and the conductive fluid cavity is placed in a permanent magnetic field.Its characteristics make the working air gap of the permanent magnetic field increase,the magnetic field strength decreases,and the sensitivity of the MHD sensor decreases.With the development of MHD sensors,miniaturization and high sensitivity,new processes are required in structural design.The insulating cylinder of the conductive fluid cavity is replaced with an insulating film,which is prepared on a permanent magnetic soft magnetic alloy magnetically conductive material and requires: With good insulation,wear resistance and thermal shock.There are few reports on the technology and process of preparing the insulating film on the soft magnetic alloy substrate.This paper studies the technology and process of preparing the insulating film on the soft magnetic alloy substrate,and evaluates the performance of the insulating film.The main contents of the paper are as follows:(1)The working principle of the MHD sensor and the significance of the preparation of the insulating film on the soft magnetic alloy substrate are described.The characteristics and requirements of the soft magnetic alloy substrate on the preparation of the insulating film and the possible impact on the performance and reliability of the MHD sensor are analyzed.(2)Investigating and analyzing the research status of the preparation of insulating films with different substrates.According to the characteristics of soft magnetic alloy substrates and films,silicon dioxide insulating films were selected and prepared by RF balanced magnetron sputtering.(3)In response to the characteristics of the MHD sensor soft magnetic alloy hollow cylinder substrate and the limitations of the plane preparation of the thin film of the balanced magnetron sputter instrument,the tooling of the rotating device was innovatively designed to realize the preparation of the thin film on the inner and outer circular surfaces and applied for a patent.(4)The preparation of silicon dioxide film on the soft magnetic alloy substrate is a new process.The main parameters of the process flow and the working parameters of the insulating film,such as working pressure,sputtering power,and substrate temperature,are studied.In order to further improve the adhesion between the film and the substrate,a titanium transition layer was added,and the process was studied.Aiming at the characteristics of the film and the characteristics of the substrate in this paper,the evaluation method was developed.(5)The method of combining single factor and orthogonal test was used to test the preparation of silica film on the soft magnetic alloy substrate,and the requirements of the film characteristics were realized.The research results show that: firstly,a 60 nm titanium thin film is coated on the soft magnetic alloy substrate,and then the second coating is carried out under the conditions of working pressure of 3m Torr,sputtering power of 70 W,substrate temperature of 250? and sputtering time of 21600 s.Silicon oxide film,the film has the best characteristics and meets the requirements.