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Lead hafnate antiferroelectric ceramic material and preparation method thereof

A ceramic material and antiferroelectric technology, which is applied in the field of antiferroelectric ceramic materials, can solve the problems of poor material compactness and stoichiometric ratio deviation, and achieve high density, accelerated densification rate, and uniform grain size.

Active Publication Date: 2022-03-08
XI AN JIAOTONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The object of the present invention is to overcome the shortcomings of the stoichiometric ratio of the ceramic material and the poor density of the ceramic material due to the easy volatilization of PbO during the sintering process of lead hafnate-based ceramics, and provide a A kind of lead hafnate antiferroelectric ceramic material and preparation method thereof

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  • Lead hafnate antiferroelectric ceramic material and preparation method thereof
  • Lead hafnate antiferroelectric ceramic material and preparation method thereof
  • Lead hafnate antiferroelectric ceramic material and preparation method thereof

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Embodiment 1 (three-layer crucible sintering method prepares PbHfO 3 ceramics):

[0038] The chemical composition of antiferroelectric ceramics is PbHfO 3 Include the following steps:

[0039] (1) Weigh PbO powder and HfO powder according to the molar ratio of 1.04:1 2 For powder, mix the weighed material, zirconium balls, and absolute ethanol according to the mass ratio of 1:2:1, then ball mill for 15 hours. After the ball milling, dry, grind and briquette in sequence, and keep warm at 850°C for 4 hours to obtain Pre-fired powder;

[0040](2) Grind the calcined powder, mix the raw materials, zirconium balls and absolute ethanol according to the mass ratio of 1:2:1, and then conduct secondary ball milling for 15 hours; after drying, grind through a 120-mesh sieve, add The polyvinyl alcohol aqueous solution (PVA) of its quality 8% carries out granulation, and the mass concentration of PVA is 5%; Cross 40 order and 80 mesh sieves respectively after granulation to obta...

Embodiment 2

[0043] Embodiment 2 (three-layer crucible sintering method prepares PbHfO 3 ceramics):

[0044] The chemical composition of antiferroelectric ceramics is PbHfO 3 Include the following steps:

[0045] (1) Weigh PbO powder and HfO powder according to the molar ratio of 1.045:1 2 For powder, mix the weighed material, zirconium balls, and absolute ethanol according to the mass ratio of 1:2:1, then ball mill for 15 hours. After the ball milling, dry, grind and briquette in sequence, and keep warm at 850°C for 4 hours to obtain Pre-fired powder;

[0046] (2) Grind the calcined powder, mix the raw materials, zirconium balls and absolute ethanol according to the mass ratio of 1:2:1, and then conduct secondary ball milling for 15 hours; after drying, grind through a 120-mesh sieve, add The polyvinyl alcohol aqueous solution (PVA) of its quality 8% carries out granulation, and the mass concentration of PVA is 5%; Cross 40 order and 80 mesh sieves respectively after granulation to ob...

Embodiment 3

[0049] Embodiment 3 (three-layer crucible sintering method prepares PbHfO 3 ceramics):

[0050] The chemical composition of antiferroelectric ceramics is PbHfO 3 Include the following steps:

[0051] (1) Weigh PbO powder and HfO powder according to the molar ratio of 1.05:1 2 For powder, mix the weighed material, zirconium balls, and absolute ethanol according to the mass ratio of 1:2:1, then ball mill for 15 hours. After the ball milling, dry, grind and briquette in sequence, and keep warm at 850°C for 4 hours to obtain Pre-fired powder;

[0052] (2) Grind the calcined powder, mix the raw materials, zirconium balls and absolute ethanol according to the mass ratio of 1:2:1, and then conduct secondary ball milling for 15 hours; after drying, grind through a 120-mesh sieve, add The polyvinyl alcohol aqueous solution (PVA) of its quality 8% carries out granulation, and the mass concentration of PVA is 5%; Cross 40 order and 80 mesh sieves respectively after granulation to obt...

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Abstract

The invention discloses a lead hafnate antiferroelectric ceramic material and a preparation method thereof. According to the preparation method, excessive lead and a three-layer crucible sintering method are combined for preparation, when the three-layer crucible sintering method is used for sintering, a PbZrO3 buried material is heated and decomposed at high temperature to generate a large number of oxygen molecules, so that local saturated vapor pressure is formed, evaporation-condensation mass transfer can be promoted at the initial stage of sintering, and the densification rate of a sintered product is increased; the aluminum oxide powder stably exists at the sintering temperature, and a sintering environment with the uniform temperature is provided; sintering is carried out under the conditions of relatively oxygen enrichment and uniform temperature, the grain size of the sample obtained through sintering is uniform, and the microstructure is compact; and the stoichiometric ratio of Pb to Hf in the sintered product can be accurately controlled by controlling excessive lead and sintering conditions, so that the stoichiometric ratio is closer to 1: 1. The ceramic prepared by the preparation method disclosed by the invention is simple in components, can obtain relatively large electrostrictive strain of 0.51% at room temperature, and has relatively good temperature stability in a temperature range of 100-175 DEG C. The method is simple in preparation process, low in cost and good in repeatability.

Description

technical field [0001] The invention belongs to the field of antiferroelectric ceramic materials, in particular to a lead hafnate antiferroelectric ceramic material and a preparation method thereof, which is a functional material with large strain at high temperature and simple composition. Background technique [0002] Due to their excellent properties, antiferroelectric materials play an irreplaceable role in applications in the fields of medicine, transportation, power electronics, and energy. Because antiferroelectric materials are accompanied by huge strain during the field-induced antiferroelectric → ferroelectric phase transition, they are widely used in the field of large displacement actuators. However, the current research mainly obtains larger strains by performing element doping, solid solution, and improving the preparation process in PLZST-based antiferroelectric materials, and the strain size can reach 0.1%-0.8%. But as far as its practical application is con...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/48C04B35/64
CPCC04B35/48C04B35/64C04B2235/3296C04B2235/6562C04B2235/96C04B2235/6567
Inventor 刘增辉万红艳李璟睿杨豪任巍叶作光
Owner XI AN JIAOTONG UNIV