| 摘要 |
PURPOSE: To impart the electric conductivity so as to enable the electric discharge machining by specifying the TiN content and making a continuous phase of TiN superfine particles present in interstices among Al2 O3 fine particles in Al2 O3 -TiN two-component-based composite ceramics. CONSTITUTION: The alumina-based composite ceramics comprise a sintered compact, containing 20-5wt.% TiN and a continuous phase of TiN superfine particles present in interstices among Al2 O3 superfine particle and having >=95% relative density and 1×10<0> to 1×10<-3> Ω.cm resistivity. The ceramics are produced by coating substantially spherical Al2 O3 particles, prepared by granulating Al2 O3 fine powder and having 0.1-100μm average particle diameter with TiN superfine particles having 0.005-0.1μm average particle diameter, press forming the resultant particles and then sintering the formed compact at >=1600 deg.C in an inert gas atmosphere. The sintered compact maintains physical, mechanical and chemical characteristics essential to alumina-based ceramics, has a high density and is capable of carrying out the electric discharge machining. |
