Sialon ceramic and method of making the same

Abstract From the Canadian patent

An alpha prime-beta prime SiAlON ceramic body (20 30), as well as a method , for making the same made from a starting powder mixture that includes silicon nitride powder that has a beta-silicon nitride content with a range having a lower limit equal to zero weight percent and an upper limit equal to about 1.6 weight percent of the silicon nitride powder. The powder mixture also includes one or more powders that provide aluminum oxygen, nitrogen, and two selected , rare earth elements to the SiAlON ceramic body wherein the selected rare earth elements are selected from at least two groupings of three specific groupings of the rare earth elements.