| 摘要 |
PURPOSE:To enhance resistance to chipping properties and specular finishing without deteriorating hardness by specifying the content of composite oxide of Y, Yb and Al and the content of composite oxide of Mg, Ca and Al in the material having the specified composition contg. Y, Yb, Mg, Ca and Zr. CONSTITUTION:In ceramic material incorporating 0.5 to 4.0 pts.wt. one or more kinds of Y, Yb expressed in terms of oxide, 2.0 to 6.0 pts.wt. Zr expressed in terms of oxide and 1.0 to 5.0 pts.wt. one or more kinds of Mg, Ca expressed in terms of oxide for 100 pts.wt. main component consisting of 60 to 80wt.% Al expressed in terms of oxide and 20 to 40wt.% Ti expressed in terms of carbide, the composite oxide (A) of one or more kinds of Y, Yb and Al is incorporated at 0.2 to 4.6% for the whole amount and also the composite oxide (B) of one or more kinds of Mg, Ca and Al is incorporated at 0.7 to 16%. When the composite oxide A is less than the lower limit, the improving effect of sintering property is not obtained. When it exceeds the upper limit, strength is lowered. When the composite oxide B is less than the lower limit, the inhibiting effect of particle growth is made small and resistance to chipping property is impaired. When it exceeds the upper limit, a crack is caused in crystal. |
