Zirconia alumina is commonly used as a sand-blasting medium. It is typically used as an abrasive

Abrasive

An abrasive is a material, often a mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away...

 in casting

Casting

In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process...

 and foundry

Foundry

A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal in a mold, and removing the mold material or casting after the metal has solidified as it cools. The most common metals processed are aluminum and cast iron...

 processes. Zirconia alumina is a mixture of zirconium oxide and aluminium oxide

Aluminium oxide

Aluminium oxide is an amphoteric oxide with the chemical formula 23. It is commonly referred to as alumina, or corundum in its crystalline form, as well as many other names, reflecting its widespread occurrence in nature and industry...

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Zirconia toughened aluminum typically consists of alumina with a 10 to 20 percent zirconia concentration, which enhances the strength of the alumina. To achieve the increase in the composite’s strength, a process known as stress induced transformation toughening takes place. Stress induced transformation toughening results in uniform internal strain, which causes the zirconia structure to crack, and the zirconia particles to switch phases. Because of this phase switch, the amount of zirconia particles increases and creates stresses within the alumina’s structure. These stresses effectively heal the crack and block further cracking—the added zirconia doubles the composite’s strength and enhances toughness between two and four times.