– Metal working
The drawing and forming or machining of the surfaces of metals demands the following properties from the plant, machine and equipment components in direct contact with the metal during metal working:
- High mechanical resilience
- High hardness
- High wear resistance
- High-temperature stability
- High thermal shock resistance
- Optimized topography in the area of contact to the metal part
- No contact reactions with the metal
- Suitable for use without lubricants
- No mechanical damage of formed metal parts
- High and uniform surface quality of the formed metal parts
- Long service lifetime in operating conditions
For working metallic surfaces by turning or milling, depending on the specific application, various materials on ceramic basis are used.
- Mixed ceramic on the basis of Al2O3
- Doped ZrO2, usually of the type Mg-PSZ
- Cubic BN
- Cutting inserts made of carbide, a composite material usually on the basis of WC-Co
Components made of such materials exhibit pronounced resistance to wear as well as reliability in operating conditions.
For plants for metal component forming like, for example, wire and sheet metal drawing or deep drawing machines, ceramic components made of Al2O3, Al2O3-ZrO2-mixed ceramics, doped ZrO2, and Si3N4 has been the established standard for decades in some cases. They are usually the precondition for cost-effective operation of such equipment.
A ceramic type proven for more than 60 years for the machining of metallic surfaces per hand is Al2O3 ceramic doped with Cr3+. The incorporation of this ion in the structure of the Al2O3 effects a significant increase in the hardness of the ceramic, which consequently enables efficient working of the surfaces.