Piezoelectric ceramic, method for making same, piezoelectric element, liquid discharge head, ultrasonic motor, and dust cleaner

摘要

A barium titanate piezoelectric ceramic having good piezoelectric properties and mechanical strength and a piezoelectric element that includes the ceramic are provided. A method for making a piezoelectric ceramic includes forming a compact containing barium titanate particles, sintering the compact, and decreasing the temperature of the compact. The sintering includes (A) increasing the temperature of the compact to a temperature range of a shrinking process of the compact; (B) increasing the temperature of the compact to a temperature range of a liquid phase sintering process of the compact; (C) decreasing the temperature of the compact to the temperature range of the shrinking process of the compact; and (D) retaining the third temperature.

主权项

1. A method for making a piezoelectric ceramic, comprising:
forming a compact composed of an oxide powder containing barium titanate particles; sintering the compact; and decreasing the temperature of the compact after the sintering, the sintering including
(A) increasing the temperature of the compact to a first temperature within a temperature range of a shrinking process of the compact;(B) increasing the temperature of the compact to a second temperature within a temperature range of a liquid phase sintering process of the compact after (A);(C) decreasing the temperature of the compact to a third temperature within the temperature range of the shrinking process of the compact after (B); and(D) retaining the third temperature after (C), wherein the difference between the first temperature in (A) and the third temperature in (C) and (D) is 30° C. or less, wherein, in (A), the first temperature is retained for 60 minutes or more and 240 minutes or less, wherein, the second temperature is retained for 5 minutes or less after (B), and wherein, in (D), a cumulative time for which the third temperature is retained is 10 hours or more and 70 hours or less.