Patent 7514383 was granted and assigned to CeramTec on April, 2009 by the United States Patent and Trademark Office.
A material based on SiAlON contain 70-97 vol. % of alpha and beta-SiAlON and an amorphous or partially crystalline grain boundary phase and 3 to 30 vol.% of a hard material. The material has an alpha-SiAlON gradient which decreases from the outside to the inside.