Zirconia

In its pure form crystal structure changes limit mechanical applications; however stabilised Zirconias produced by addition of Ytrium Oxides can produce very high strength, hardness and particularly toughness. With its biocompatibility and resistance to wear, is ideally suited for a wide variety of medical implant applications, from artificial joints to implantable electronic sensors, stimulators and drug delivery devices. For well over a decade, zirconia and other ceramics have successfully proven their ability to withstand the harsh environment of the human body.

Yttria Partially Stabilised Zirconia exhibits crack resistance properties due to the metastable nature of the tetragonal phase. An applied stress causes the tetragonal phase to convert to monoclinic with the associated volume expansion. This phase transformation can then put the crack into compression, retarding its growth, and enhancing the fracture toughness. This mechanism is known as transformation toughening, and significantly extends the reliability and lifetime of products made with Stabilized Zirconia.

Typical zirconia characteristics include:

• Ultra fine grain
• High density
• Very high mechanical strength
• High strength and fracture toughness
• High hardness and wear resistance
• Low thermal conductivity (20% that of Alumina)
• Good chemical resistance
• Ionic conductivity
• Ceramic-to-metal brazed assemblies

Typical Zirconia applications include:

• Ablation tips
• Neurostimulation housings
• Dental abutments
• Cutting blades