| 摘要 |
PROBLEM TO BE SOLVED: To heat-treat a ceramic obtained by baking a ceramic containing an evaporating component such as lead without causing the warpage or deforma tion of the ceramic. SOLUTION: PbO, TiO2 , ZrO2 , MgO, Nb2 O5 and Cr2 O3 as starting raw materials are weighed and blended so as to provide a chemical formula of Pb(Mg2/8 Nb5/8 Cr1/8 )O3 -PbZrO3 -PbTiO3 and the resultant blend is then wet mixed, dehydrated, dried and calcined at 900 deg.C for 2hr. A binder is further added and mixed with the calcined powder and the obtained mixture is dehydrated and graded. The resultant graded powder is press formed into the form of a disk having a shape of 30mm diameter × 0.3-1.5mm thickness after the baking and the formed compact is then baked. The baking is carried out under conditions of removing a binder, etc., up to 500 deg.C in the atmospheric air, adding PbO vapor in an amount so as to afford 400Pa into the baking atmosphere to the temperature range of 500-1,000 deg.C and baking the compact at 1200 deg.C maximum temperature for 2hr without any regard to the partial pressure of the PbO when the temperature exceeds 1,000 deg.C. |
