Milling ceramic made from metaloxide powders having a bimodal particle size distribution

摘要

Bimodal metal oxide powder or oxide-binder composite with optionally surface-modified metal oxide powder; and optionally surface- modified nanoscalar metal oxide powder is such that (A) has d50 = 0.2-12 microns and (B) has d50 = 10-300 nm, with maximum ratio d50 (A) : d50 (B) = 40 : 1 and amount ratio = 0.1-99.9 : 99.9-0.1; and bimodal powder of gamma-aluminum oxides of average particle size 1 micron and 70-120 nm respectively is excluded. Independent claims are also included for (i) production of the bimodal metal oxide powder by mixing (A) and (B) and granulating the mixture or by granulating (A) and then mixing it with (B); (ii) production of ceramics by cold compressing the powder, pre-sintering at 300- 1100 degrees C for 0.5-8 hours to give a green product and then sintering; and (ii) metal oxide ceramics comprising (A) and (B) as above.