Designer's Guide Results
The following is a list of materials, selected and ranked per your specification.

MaterialMaximum Working Temperature
Cubic Zirconia2500 °C
Zirconia-TZP2400 °C
Sapphire2000 °C
Boron Nitride850-3000 °C
Inert Atm
Alumina 99.9%1900 °C
Alumina 99.5%1750 °C
Alumina 94%1700 °C
Sialon1700 °C
Silicon Carbide Reaction Bonded1650 °C
Silicon Carbide Sintered1650 °C
Zirconia Toughened Alumina (ZTA)1650 °C
Reference Materials
Stainless Steel1800 °C
Tool Steel800 °C
Diamondn/a

All properties values are at room temperature unless otherwise noted. Engineering data are representative, and are not intended as absolute nor warrantable. Data shown is blended from multiple sources and therefore illustrates the marketplace. The relative rankings are approximate and are based on representative values if the particular material has a range of values for a given property.

Wikipedia Definition(s) :  Maximum Working Temperature;

Check Different Properties

Please Note:  This Designers guide is compiled of materials currently machined by Insaco and a few others included for reference.