SUOYI Customized 4.5Y Yttrium Stabilized Zirconia Powder for Oxygen Sensors

SUOYI's customized 4.5Y yttrium-stabilized zirconia powder (4.5YSZ) is a core electrolyte material for oxygen sensors, combining high oxygen ion conductivity, good mechanical strength, and thermal stability. It is suitable for high-temperature oxygen measurement applications such as automotive λ sensors and industrial flue gas probes.

Core Principles and Material Positioning of Yttrium Stabilized Zirconia Powder
Pure zirconia (ZrO₂) is a monoclinic phase at room temperature. High-temperature phase transitions are accompanied by dramatic volume changes, making it prone to cracking and lacking oxygen ion conductivity. After incorporating 4.5 mol% Y₂O₃ (4.5Y), a partially stabilized zirconia (4.5YSZ) is formed, consisting mainly of a tetragonal phase with a small amount of cubic phase:

- At high temperatures (>300℃), it generates a large number of oxygen ion holes, exhibiting excellent oxygen ion conductivity and extremely low electronic conductivity, making it an ideal solid electrolyte.

- Following the Nernst equation: the difference in oxygen partial pressure on both sides forms a concentration potential, accurately corresponding to oxygen concentration, which is the working basis of the zirconia oxygen sensor.

  Application Scenarios of 4.5Y Yttrium Stabilized Zirconia Powder

- Automotive Oxygen Sensors (λ Sensors): 4.5YSZ tubular electrolyte, coated internally and externally with Pt electrodes, measures exhaust gas oxygen concentration, and uses feedback to control the air-fuel ratio, reducing emissions.

- Industrial Flue Gas Oxygen Probes: 4.5YSZ sheet/tubular elements are used in boilers, incinerators, and metallurgical kilns to monitor oxygen concentration for optimized combustion, energy saving, and emission reduction.

- Solid Oxide Fuel Cells (SOFCs): 4.5YSZ electrolyte film, combining conductivity and fuel/oxidant barrier functions.

- 3Y (3 mol% Y₂O₃): Highest strength (1000–1200 MPa), but low conductivity; suitable for structural ceramics, not suitable for high-sensitivity oxygen sensors.

- 4.5Y (4.5 mol% Y₂O₃): Optimal balance, balancing conductivity and strength, the mainstream choice for oxygen sensors.

- 5Y/8Y (5/8 mol% Y₂O₃): High conductivity (8Y highest), but low strength (400–600 MPa), prone to cracking, suitable for low-load, low-temperature applications.

4.5Y yttrium-stabilized zirconia powder is the gold standard material for oxygen sensors. By precisely controlling the Y₂O₃ doping amount and powder characteristics, high sensitivity, fast response, and long lifespan oxygen measurement performance can be achieved, widely used in automotive, industrial, and energy fields.