Development Of U-type Zirconia Solid Electrolyte Oxygen Sensor

Zirconia solid electrolyte oxygen sensor has been widely used in automobile engines,waste incinerators,power plant boilers,especially controllable atmosphere heat treatment and other industrial fields.It has played a positive role in reducing air pollution,improving fuel combustion efficiency and parts carburizing heat treatment quality.At present,the structure of oxygen sensor(also known as oxygen probe)for controlled atmosphere heat treatment at home and abroad mainly has two forms : one is laser welding structure of cylinder zirconia and corundum ceramic tube;the other is the structure of zirconia ball and corundum ceramic tube pressed and sealed by spring.The task of this project is to develop a new type of oxygen sensor with stable and reliable performance and long service life to replace the imported oxygen sensor.Firstly,the overall structure of the oxygen sensor is designed,and the structure and function of the main components are described in detail.The working principle of oxygen sensor and the preparation process of platinum electrode on the inner side of zirconia tube were introduced.The failure reason of platinum electrode in reducing atmosphere was analyzed.The sealing process of zirconia tube and corundum porcelain tube was tested,and the third sealing method was determined to have the best sealing performance by comparison test.Self-made 1200 °C vertical hightemperature small electric furnace,used for sleeve sealing ceramic glaze sintering;the material and preparation process of the oxygen sensor electrode were tested.Among the three different materials and production processes,the 0Cr20Ni80 heat-resistant wire welded platinum wire disassembly internal electrode has the best performance.Self-made welding time controller for0Cr20Ni80 heat-resistant wire and platinum wire welding;the assembly of the finished oxygen sensor was completed.