Bismuth ferrite-barium titanate lead-free piezoelectric ceramic as well as preparation method and application thereof

Abstract

The invention relates to bismuth ferrite-barium titanate lead-free piezoelectric ceramic and an application thereof. The chemical formula of the bismuth ferrite-barium titanate is (1-x)BiyFeO3-xBaTiO3, x and y are mole fraction, x is 0.3-0.4, y is 0.6-1.2, the raw materials for preparing the bismuth ferrite-barium titanate comprise Bi2O3, Fe2O3, BaCO3 and TiO2, and the preparation method comprises the following steps: reacting Bi2O3, Fe2O3, BaCO3 and TiO2 at 780-850 DEG C to prepare a precursor; and performing granulation treatment, forming treatment, glue discharging treatment, sintering treatment, specific annealing treatment, silver firing treatment, quenching treatment and polarization treatment on the precursor. The microstructure, density and charge defect concentration of the ceramic are improved through annealing treatment, the ceramic generates lattice distortion in the high-temperature quenching process through quenching treatment after silver firing, and the piezoelectric property of the ceramic is cooperatively improved.

Description

technical field [0001] The invention belongs to the technical field of perovskite-type lead-free piezoelectric ceramics, and in particular relates to a preparation method and application of bismuth ferrite-barium titanate lead-free piezoelectric ceramics with high-voltage electrical properties. Background technique [0002] Piezoelectric ceramics is a functional ceramic material that can realize mutual conversion between electrical energy and mechanical energy. It is widely used in electronic components and is the cornerstone of the electronic information industry. Since the invention of piezoelectric ceramics, researchers have conducted a lot of research on it, and made many gratifying achievements, which greatly promoted the development of piezoelectric ceramics. Among them, lead-based piezoelectric ceramics are the most widely used, such as the most commonly used lead zirconate titanate (PZT) material, but lead-containing piezoelectric ceramics will inevitably cause serio...

AI Technical Summary

Problems solved by technology

where BaTiO 3 The earliest application of ceramics, but with the development of science and technology, BaTiO with low Curie temperature (Tc=120°C) 3 Ceramics can no longer meet the needs of the rapid development of electronic equipment performance

Although bismuth sodium titanate-based lead-free piezoelectric ceramics have a large Curie temperature and remnant polarization at room temperature, it is difficult to completely polarize, the piezoelectric performance is not high, and the temperature stability is poor.

Although lead-free piezoelectric ceramics with bismuth layer structure has a high Curie temperature, it is difficult to completely polarize, and its application is greatly limited.

Potassium sodium niobate-based lead-free piezoelectric ceramics have made great progress after a lot of research. The modified potassium sodium niobate-based ceramics have high piezoelectric properties, but their Curie temperature is usually not high, and Due to the volatilization of K and Na elements, the sintering temperature range is narrow, and the temperature stability of its performance is poor.

BiFeO 3 Ceramics have received a lot of attention because of their extremely high Curie temperature, but since pure BiFeO 3 Ceramics are difficult to prepare and have poor piezoelectric properties, so the researchers used BiFeO 3 and BaTiO 3 Bismuth ferrite-barium titanate lead-free piezoelectric ceramics with high Curie temperature have been prepared by mixing, which will become a strong competitor that is expected to replace lead-containing piezoelectric ceramic materials

[0004] Although researchers have done a lot of research on bismuth ferrite-barium titanate lead-free piezoelectric ceramics, their piezoelectric performance is still not ideal, and the performance has a great relationship with the preparation process of ceramics.

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