Zirconia Toughened Alumina

Zirconia Toughened Alumina (ZTA) is a composite of alumina and zirconia. The main advantage of zirconia toughened alumina is the additional strength and toughness lower cost. The combination of aluminum oxide and 10-20% zirconium oxide provides much higher strength, toughness, hardness, and wear resistance than alumina alone. A process called transformation toughening is the phenomenon that increases the fracture toughness of ZTA. When placed under stress, the zirconia particles change their crystal structure from a tetragonal to a monoclinic structure, causing a volume expansion that compresses the surrounding crack in the alumina matrix.