Study On The Preparation And Properties Of Limiting Current Oxygen Sensor Based On Dense Diffusion Barrier Layer

The dense diffusion barrier layer limit current oxygen sensor is a new type of oxygen sensor developed in recent years,with the advantages of high accuracy,fast response and no need to reference gas etc..Laser cladding technology is in the substrate surface added cladding material,and the use of high energy density laser beam to and the surface of the base material layer with melting method,used for the preparation of oxygen sensor,and solid electrolyte with more solid dense diffusion barrier layer,from and to improve the performance of the oxygen sensor.In this paper,Solid mixed conductor consisting of La0.8Sr0.2Ga1-xFexO36(x=0.6?0.8?1)was prepared from a stoichiometric mixture of La2O3(3.5N),SiCO3(99%),Ga2O3(4N)and Fe2O3(4N)using solid-phase method under high temperature;use La2O3(3.5N),SrCO3(99%),Ga2O3(4N)and MgO style(98.5%)as the synthesis of solid electrolyte materials;Use 5 mol yttrium stabilized zirconia sintering as the solid electrolyte materials 5YSZ.Based on use LSF as cladding layer material,LSGM and 5 YSZ as base material,by laser cladding experiment to find the reasonable laser parameters.Use part of the laser cladding sample do analysis by scanning electron microscopy(SEM)and EDS spectrum.Dense diffusion barrier limiting current oxygen sensors are prepared by ceramic composite process and pressure sintering together method,and then test performance of sensor,get the main conclusions as following;1.The cladding layer thickness with laser power increased and increased with the increase of the scanning speed decreases,decreases with the increase of spot diameter;the width of cladding layer increases with the increase of laser power,decreases with the increase of the scanning speed,with increasing beam diameter increases.Laser power,scanning speed and laser spot size are the geometrical morphology of the cladding layer..2.When the quality of the preset powder is 0.3 g(about 2mm thick),the optimum parameters of laser cladding are:laser power 29W,scanning speed 1mm·s-1,the spot diameter is 1mm.3.Compared with the conventional sintering method,the dense diffusion barrier layer prepared by laser cladding is more compact,and solid electrolyte with solid electrolyte..4.The oxygen sensor ceramic composite prepared by the existence of the limit current platform in 3%oxygen volume fraction and 700?850?.