摘要 |
A ceramic comprising: a) between 20 w/o and 90 w/o unnecked composite grains comprising: i) between 5 w/o and 100 w/o silicon nitride and ii) between 0 w/o and 95 w/o free silicon, said composite grains having lengths of at least 50 microns and widths of at least 10 microns; and b) between 10 w/o and 80 w/o matrix grains having lengths of less than 20 microns. |