Method for preparing high performance piezoelectric ceramics by reactive solid phase growth

Abstract

The invention belongs to the technical field of functional material preparation. The single-crystal or textured leadless piezoelectric ceramic is prepared by a reaction solid-phase growth technology, a pre-synthesis process is saved, the formation of pyrochlore phase is suppressed, the ceramic density is increased, and the electrical performance is improved; meanwhile, the problems of difficult growth, high cost and long cycle of a piezoelectric single crystal are solved; and (K, Na)NbO3(NKN)-based leadless piezoelectric ceramic with high density and good electrical performance is obtained.

Description

Technical field [0001] The invention belongs to the technical field of functional material preparation; the single-crystal or textured lead-free piezoelectric ceramics are prepared by a reactive solid phase growth process, so as to omit the pre-synthesis process, inhibit the formation of pyrochlore phase, increase the ceramic density, and improve the electrical properties. Solve the problems of piezoelectric single crystal growth, high cost, and long cycle; obtain (K,Na)NbO with higher density and good electrical properties 3 (NKN)-based lead-free piezoelectric ceramics. Background technique [0002] With the promotion of environmental protection awareness and the deepening of the concept of sustainable development, the development of environmentally compatible, high-performance lead-free piezoelectric materials to replace lead zirconate titanate (PbZrO 3 -PbTiO 3 , PZT)-based piezoelectric ceramics have become a subject of important scientific significance in the field of dielect...

AI Technical Summary

Problems solved by technology

[0003] Since the early 1960s, people have studied niobate ((K,Na)NbO 3 , NKN)-based lead-free piezoelectric ceramics with perovskite structure; the traditional preparation process of NKN-based ceramics includes two crushing (or ball milling) and two heat treatments of calcination and sintering. The production process is cumbersome, easy to introduce impurities and energy consumption At the same time, because Na and K are volatile, it is generally necessary to adopt methods such as hot pressing and spark plasma sintering to obtain dense NKN-based ceramics; therefore, in order to optimize the preparation process of NKN-based ceramics and improve the pressure of NKN-based ceramics In order to achieve high performance of NKN-based ceramics, it is necessary to develop new ideas

[0004] With Pb(Mg 1 / 3 Nb 2 / 3 )O 3 -PbTiO 3 The successful development of the relaxor ferroelectric single crystal represented by (PMNT) has been called "an exciting breakthrough" in the field of ferroelectricity in the past 50 years; the high performance of PMNT single crystal has guided the new direction of material preparation - pressure The single crystallization of electrical materials is expected to improve the piezoelectric properties of materials; however, due to the complex composition of relaxor ferroelectric single crystals, there is competition between the two phases of perovskite and pyrochlore during melt crystallization, and the high-temperature melt of PbO has great influence on the piezoelectric properties of materials. Pt crucibles will be severely corroded, and the composition segregation, phase transition and domain transition near the best-performing quasi-isomorphic phase boundary (MPB) are more sensitive, making it difficult to prepare large-sized PMNT single crystals

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