Plasma-sprayed ceramic of aluminum oxide with 3, 13 or 40 percent titania. Titania lowers the melting point and raises toughness and density, turning the coating from white alumina to gray and then nearly black. It is used on pump parts, rolls, textile guides and sealing surfaces. Pure white alumina is chosen instead where electrical insulation matters.
Go with the 87/13 alumina-titania on the guide rolls, the straight white alumina keeps chipping.
Also heard as
- Al2O3-TiO2
- 87/13
- 97/3
- gray alumina
Related terms
Chrome oxide
Plasma-sprayed chromium oxide, a hard, dense ceramic for wear parts and polished sealing surfaces.
Plasma spray
Spraying powder through an electric arc plasma jet hot enough to melt ceramics and refractory metals.
Fused and crushed
Describes powder made by melting material into an ingot, then crushing and screening it to size.
Sealer
A thin liquid resin brushed or soaked into a sprayed coating to fill its connected porosity.