Werkstoff auf Siliciumnitrid-Basis, Verfahren zu dessen Herstellung und dessen Verwendung

DE 102006059402 A1 UPAB: 20080627 NOVELTY - Production of silicon nitride-based materials comprises preparing a powdered mixture of 40 - 70 vol% of fine grain alpha - and/or beta -Si3N4, a sintering additive and 25 - 60 vol% of large grain alpha -Si3N4. The mixture is compressed at a temperature above 1450degrees C so that the large grain fraction remains as alpha Si3N4. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for silicon nitride-based materials containing 40 - 75 vol% of acicular beta -Si3N4, at least one sintering additive which produces an amorphous or partially crystalline grain boundary phase, and 25 - 60 vol% of alpha -Si3N4 with an average grain size of 0.2 - 3 microns. USE - As a cutting material (claimed). ADVANTAGE - The materials have high hardness and fracture toughness and good thermal conductivity