| 摘要 |
PROBLEM TO BE SOLVED: To obtain placing powder not causing the contamination of a body to be fired due to a reaction and easy to recover and reutilize by specifying the particle diameter of zirconia-base sintered spheres. SOLUTION: This placing powder consists of zirconia-base sintered spheres whose average particle diameter is larger than 0.025mm and smaller than the min. length of a face of a body to be fired. The face comes in contact with a setter. The density of the powder is preferably >=90%, especially >=95% of the theoretical density. In the case of <90%, placing powder adheres to a body to be fired or particles of the powder adhere to each other. The pref. shape of this placing powder is prefectly spherical and the sphericity calculated by the equation (sphericity)=(min. diameter of section)/(max. diameter of section) from the projected sections of arbitrary >=10 particles of the powder is desirably >=0.8. The sphericity of a perfect sphere is 1. When the sphericity is >=0.8, point contact with a body to be fired is ensured and adhesion to the body is hardly caused. |
