| 摘要 |
PROBLEM TO BE SOLVED: To obtain a ceramic material having superplasticity to enable precision work by using a molded and sintered material of Al2 O3 particles containing dispersed ZrO2 particles and specifying the tensile elongation at a specific elongation speed to a specific level or above. SOLUTION: The objective material has a tensile elongation of >=200% at 1,450 deg.C or 1,500 deg.C under an elongation speed of >=0.1 mm/min. The average crystal particle diameter (dA) of the Al2 O3 in the sintered material is <=0.9 μm as the value calculated by the formula (L is the length of measured line; NAA is the number of alumina crystal boundaries crossing the measured line L; NAZ is the number of boundaries of crystal grains composed of alumina and zirconia crossing the measured line L; V is the volume fraction of alumina). The volume fraction of Al2 O3 is >=85%. The ZrO2 particle is pure ZrO2 or ZrO2 containing Y2 O3 or CeO2 and the volume fraction of ZrO2 in the sintered material is 5-15%. |
