Research On Correlation Between Structures And Property Of Wide Band Lambda Sensor

With the rapid development of the world economy,car amount is increasing rapidly.Incomplete combustion of fuel in consequence of defects of internal combustion engine causes large amounts of pollutants emitted.Lambda oxygen sensors are widely used in gasoline engines which can reduce pollution and energy consumption effectively.But for fuel efficient combustion engine such as diesel engines and gas engines,which lambda is not equal to 1,use wide band lambda sensor to control fuel combustion.This article is based on preparation process our laboratory has,and analysis difficulties encountered in the experiments,optimizes tape casting slurry preparation,tape casting,screen printing,laminate,YSZ and alumina oxide high temperature total sintering,and discusses the preparation and detection method of wide band lambda sensor.The main research conclusion are as follows:?Optimization of tape casting slurry preparation.YSZ organic tape casting slurry formula is 2.5g fish oil,30 g methylbenzene,30 g ethanol,11 g PVB,3g PEG-400 and 2.5g BBP every 100 g YSZ powder.YSZ water-based tape casting slurry formula is 4g TEA,20 g DI water,18 g 30wt%PVA solution,5g PEG-400 and 1g BBP every 100 g YSZ powder.Aluminium oxide organic tape casting slurry formula is 3g fish oil,40 g methylbenzene,40 g ethanol,15 g PVB,5g PEG-400 and 4g BBP every 100 g aluminium oxide powder.We can get fault-free green tapes with above-mentioned formula.?Optimization of screen printing parameters.We can use 300?m8YSZ laminated tape casting green tape as substrate and 200 meshes 20×15cm polyester halftone to get good results when take 3mm between stencil and mesh,55?60? baking temperature lasting 20?25 minutes as parameters.?Optimization of lamination.Laminating green tape for 10 minutes under condition 1Mpa pressure and 80?,we can not get good laminate effect using ethanol or methylbenzene saparately as additive;we can get good laminate effect both using 2wt%BBP+98wt%methylbenzene solution and 1wt% organic carrier +99wt% methylbenzene solution.?Optimization of YSZ and alumina oxide high temperature total sintering.Glass poder can promote alumina oxide sintering as fluxing agent during YSZ and alumina oxide high temperature total sintering.We can use 2.5wt% glass powder with leveling technology of lasting 4h under 1350? to get YSZ and alumina oxide high temperature total sintering sanple with flat surface and well combined interface.We can use 70?m thickness alumina oxide green tape instead of alumina oxide printing layer as insulating layer to reduce deformation and promote interface combining of YSZ and alumina oxide high temperature total sintering sanple.?Glass seals leaking air channel.Glass with sodium silicate added is not good for combination of ceramic substrate.Glass with YSZ added is not good for combination of ceramic substrate and make the glass turbidity because YSZ is unable to melt into the glass.We sinter 1000? glass powder under 1100? for 30 min,then cooling it at the rate of 1?/min between 1100??800?,then furnace cooling between 800? and room temperature,can get good sealing effect.?Extraposition of heating resistor.Using structure with external heating resistor can well heat oxygen sensors and increase finished product ratio.?Rapid detection methods of wide band lambda sensor in laboratory.Alcohol lamp test can detect air tightness of air channel,combined with glass seals can get sample with air tight air channel.Electrochemical impedance spectrum can test solid electrolyte conductivity of cell,electrode resistance and determine the best working temperature.