Patent ID: 7550401

Claim:
A method of making a sintered ceramic composition comprising: a. providing a powder comprising at least 50 wt. % boron carbide and 0.05 wt. % to 30 wt. % of at least one oxide selected from the group consisting of oxides of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; b. milling said powder to form a milled powder; c. drying said milled powder to form a milled, dried powder; and d. consolidating said milled, dried powder at a temperature in the range of 1500° C. to 2200° C. to form a sintered ceramic composition having a density of at least 90% of theoretical density, wherein at least one of said providing step and said milling step introduces Zr into said powder so that said sintered ceramic composition comprises zirconium diboride in an amount in the range of 1 wt. % to 10 wt. %.