| 摘要 |
1. A process for the shaping of dense polycrystalline ceramic components, characterized in that a ceramic material is chosen which has a mean initial particle size (D0 ) not exceeding 10 mu m, a range of forming temperatures is determined by measuring the rate of growth of particles of the material prior to forming, the said temperature range being such that the relationship see diagramm : EP0094354,P6,F1 where Dmax =maximum tolerable particle size in the shaped component when in service, and the relationship see diagramm : EP0094354,P6,F2 where epsilon max=maximum necessary local deformation, are satisfactory, and this material is heated within a temperature range suitable for producing an increase in the mean particle size, through out the operation, up to a final size (D) equal to at most 20 mu m, and in that the forming operation is carried out simultaneously, during the growth of the particles at a rate of local deformation see diagramm : EP0094354,P6,F3 (where epsilon=Ln l/l0 , l0 being the initial linear dimension of the particles and l their linear dimension after formation), which is continuously correlated with the particle growth parameter see diagramm : EP0094354,P6,F4 (D being the mean particle size and see diagramm : EP0094354,P6,F5 being the instantaneous growth rate) so as to satisfy the condition see diagramm : EP0094354,P6,F6 where alpha=maximum tolerated cavitation factor in the material when forming is complete, expressed in % by volume. |
