| 摘要 |
PURPOSE:To achieve a compact and uniform sintered body by setting the ambiance when increasing temperature from normal temperature to firing temperature and that at firing temperature to a specific ambiance. CONSTITUTION:In the ambiance on firing from normal temperature to firing temperature, helium concentration is 50vol.% or higher and the remaining part is formed by an inactive gas. Then, the helium concentration is 50vol.% or larger, oxygen concentration is 10vol.% or larger, oxygen concentration is 10vol.% or larger, and the remaining part is formed by the inactive gas at the firing temperature. PbO, ZrO2, and TiO2 raw material powders are ground by a ball mill and are ground and dried again by the ball mill after firing. After polyvinyl alcohol is added to the dried powder for granulation, a circular- plate-shaped piezoelectric porcelain formation body is formed by hydraulic press. The piezoelectric porcelain formation body is loaded into an alumina crucible with ZrO2 powder on the bottom, the ambiance when increasing temperature normal temperatures to calculation temperature is set to He concentration: 50vol.% and then that on firing temperature is set to helium concentration: 50%vol.% and O2 concentration: 10vol.% for firing. A constituent other than He and O2 in the ambiance is N2 gas. |
