Patent ID: 7276193

Claim:
A method for forming an article from an ultrafine particle brittle materials, comprising the steps of: applying a mechanical impact force or a pressure to the ultrafine particle brittle material so as to have 10% to 90% in number of all the resultant ultrafine particle brittle material particles have a primary particle diameter less than 50 nm; subjecting the ultrafine particle brittle material to a heat treatment at a temperature in the range of from 200 to 1200° C. that is not higher than the sintering temperature thereof, wherein the heat treatment of the ultrafine particle brittle material particles having a primary particle diameter less than 50 nm extinguishes or reduces the number of said particles to 50% or less in the heat-treated ultrafine particle brittle material; and then applying a mechanical impact force not smaller than the crushing strength of the ultrafine particle brittle material to the heat-treated ultrafine particle brittle material by means of particle collision for generating crushed faces on the crushed ultrafine particle brittle material, thereby joining the individual resultant particle brittle materials together to form said article made of the ultrafine particle brittle material.