Zirconia Ceramics

Zirconia ceramics materials provide excellent erosion, corrosion and abrasion resistance along with temperature resistance, fracture toughness and strength. These ceramic components are used in extreme service applications that take advantage of their superior wear and corrosion resistance. Its fine grain size enables excellent surface finishes and the ability to hold a sharp edge.

Although it retains many properties including corrosion resistance at extremely high temperatures, zirconia does exhibit structural changes that may limit its use to perhaps only 500°C. It also becomes electrically conductive as this temperature is approached.

Zirconia is commonly blended with either MgO, CaO, or Yttria as a stabilizer in order to facilitate transformation toughening. This induces a partial cubic crystal structure instead of fully tetragonal during initial firing, which remains metastable during cooling. Upon impact, the tetragonal precipitates undergo a stress induced phase transformation near an advancing crack tip. This action expands the structure as it absorbs a great deal of energy, and is the cause of the high toughness of this material. Reforming also occurs dramatically with elevated temperature and this negatively affects strength along with 3-7% dimensional expansion. The amount of tetragonal can be controlled by additions of the blends above to balance toughness against loss of strength.

Material 

1) Tetragonal zirconia polycrystal (TZP)

Zirconia Yttria blends of approximately 3% are called tetragonal zirconia polycrystal or TZP, and have the finest grain size. These grades of Zirconia exhibit the highest toughness at room temperature, because they are nearly 100% tetragonal, but this degrades severely between 200 and 500°C as these irreversible crystal transformations also cause dimensional change.

2) Partially Stabilized Zirconia(PSZ)

Zirconia PSZ are cream colored blends with approximately 10% MgO and are high in toughness, retaining this property to elevated temperatures. They are somewhat lower in cost but have larger grain structure.

3) Cubic Zirconia

This single crystal optically clear form of ZrO2 has a relatively low fracture toughness and strength, but very high thermal shock resistance.

Characteristics

  • High mechanical strength
  • Excellent wear and abrasion resistance
  • Excellent corrosion resistance
  • High impact resistance and toughness
  • Superior thermal shock resistance
  • Low thermal conductivity

Application

  • Ceramic Valve components
  • Ceramic Pump liners
  • Ceramic Roller
  • Ceramic Plugs
  • Ceramic Sleeves
  • Ceramic Pistons
  • Ceramic Nozzle
  • Precision ceramic balls
  • Ceramic Spools
  • Ceramic Shaft
  • Ceramic Press tooling