High Curie temperature lead-free SNKBT piezoelectric ceramic and preparation method thereof

Abstract

The invention discloses a high Curie temperature lead-free SNKBT piezoelectric ceramic with a chemical formula of Sr0.9(Na0.5-xKxBi0.5)0.1Bi4Ti4O15, wherein x equals o 0.12-0.32wt.%. The method comprises the steps of: preparing ingredients of Na2CO3, K2CO3, SrCO3, material TiO2, and Bi2O3 according to their stoichiometric ratio, carrying out ball milling for 4h, drying, sieving, and synthesizing at 850 DEG C; then conducting secondary ball milling, drying, sieving, and adding 7wt.% of PVA water solution for granulation, and molding into a blank; discharging rubber, sintering the blank at 1100 DEG C for, then coating a layer of silver on the upper and lower surfaces of the piezoelectric ceramic, carrying out sintering permeation, and polarizing in silicone oil of 170 DEG C under the electric field strength of 10KV / mm for 5-10min so as to produce the high Curie temperature lead-free SNKBT piezoelectric ceramic. The invention overcomes the shortcomings of doping of other elements and large amount of replacement to obtain high voltage characteristic in the preparation process; and the system reduces the coercive field and low voltage characteristic of the electrical ceramic caused by inadequate polarization, improves the preparation process, and improves the piezoelectric properties.

Description

Technical field [0001] The invention belongs to a ceramic composition characterized by composition, and particularly relates to a high Curie temperature lead-free SrBi 4 Ti 4 O 15 -(Na 0.5 Bi 0.5 )Bi 4 Ti 4 O 15 -(K 0.5 Bi 0.5 )Bi 4 Ti 4 O 15 Piezoelectric ceramics and preparation method thereof Background technique [0002] Piezoelectric ceramics are a kind of functional materials that are researched and developed by countries all over the world, which can realize mutual conversion between mechanical energy and electrical energy. It is widely used in various fields of material engineering, sound and light, as well as human daily life and production. Although since the discovery of barium titanate-based piezoelectric ceramics, piezoelectric ceramics have rapidly been commercialized and used in the pickup of phonographs. However, people's exploration of piezoelectric materials and research on the principle of piezoelectric effect are in the ascendant. At present, traditional pie...

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Problems solved by technology

[0003] Pure MBi 4 Ti 4 o 15 Ceramics have the following disadvantages: First, the piezoelectric activity is low, compared with PZT lead-containing series ceramics, there is still a big gap

Na 0.5 Bi 4.5 Ti 4 o 15 、K 0.5 Bi 4.5 Ti 4 o 15 and SrBi 4 Ti 4 o 15 are three kinds of bismuth layered structure materials with relatively excellent properties. However, so far, there is no research report on the large-scale doping substitution of the three

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