Wear Resistance Industrial Ceramic Coated Pistons Alumina Plunger Yellow Color

1. Description

Al₂O₃ is an electrical insulator but has a relatively high thermal conductivity (30 Wm⁻¹K⁻¹) for a ceramic material. Aluminium oxide is insoluble in water. In its most commonly occurring crystalline form, called corundum or α-aluminium oxide, its hardness makes it suitable for use as an abrasive and as a component in cutting tools.

Aluminium oxide is responsible for the resistance of metallic aluminium to weathering. Metallic aluminium is very reactive with atmospheric oxygen, and a thin passivation layer of aluminium oxide (4 nm thickness) forms on any exposed aluminium surface. This layer protects the metal from further oxidation. The thickness and properties of this oxide layer can be enhanced using a process called anodising. A number of alloys, such as aluminium bronzes, exploit this property by including a proportion of aluminium in the alloy to enhance corrosion resistance. The aluminium oxide generated by anodising is typically amorphous, but discharge assisted oxidation processes such as plasma electrolytic oxidation result in a significant proportion of crystalline aluminium oxide in the coating, enhancing its hardness.

Aluminium oxide was taken off the United States Environmental Protection Agency's chemicals lists in 1988. Aluminium oxide is on EPA's Toxics Release Inventory list if it is a fibrous form.

The applications for alumina advanced ceramics are heavy-duty forming tools, substrates and resistor cores in the electronics industry, tiles for wear protection and ballistics, thread guides in textile engineering, seal and regulator discs for valves, heat-sinks for lighting systems, protection tubes in thermal processes or catalyst carriers for the chemicals industry.

2. Technical Property