Low-temperature cold sintering preparation method of barium titanate ferroelectric ceramic

A technology of ferroelectric ceramics and barium titanate, which is applied in the field of sintering and preparation of barium titanate ferroelectric ceramics, can solve the problems of uncontrollable key performance indicators, restrict mass production, increase in grain size, etc., and achieve broad industrial application Prospects, effects of excellent dielectric properties and impact toughness, low energy consumption

Active Publication Date: 2017-04-26
HARBIN ENG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For ceramic materials, the increase of sintering temperature and the extension of holding time are conducive to the realization of densification; but the grain size of the material will increase accordingly (making key performance indicators such as dielectric constant uncontrollable), and at the same time, high temperature sintering It will bring great cost loss, which restricts its mass production in industry

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Ba(OH) 2 and TiO 2 The powder is put into the solvent (the solvent is deionized water) according to the molar ratio of 1.2:1, ultrasonically dispersed and stirred for 20-40min to prepare a suspension with a Ba(OH)2 concentration of 0.1mol / L.

[0021] Select BaTiO with a purity of 99.5% and an average particle size of 40 nm 3 Nanoscale powder and BaTiO with a purity of 99.9% and an average particle size of 400nm 3 Submicron powder, according to the size of the prepared BaTiO3 ceramics and related devices, calculate the quality of the required BaTiO3 powder, add BaTiO3 nanometer powder and BaTiO3 submicron powder according to the mass ratio of 1:1, add 25wt.% in step 1 The prepared Ba(OH)2 / TiO2 suspension was ground in a mortar for 0.5-1 h.

[0022] After cold pressing at room temperature for 10 minutes, keep the temperature at 180°C and hold the pressure for 3 hours, and the pressure is 450MPa. BaTiO 3 The ceramic preform was dried at 200° C. for 12 hours.

[0023]...

Embodiment 2

[0026] Ba(OH) 2 and TiO 2The powder is put into the solvent (the solvent is deionized water) according to the molar ratio of 1.2:1, ultrasonically dispersed and stirred for 30min to obtain Ba(OH) 2 A suspension with a concentration of 0.1mol / L.

[0027] Select BaTiO with a purity of 99.8% and an average particle size of 50nm 3 Nanoscale powder and BaTiO with a purity of 99.9% and an average particle size of 500nm 3 Submicron powder. According to preparing BaTiO3 pottery and related device size, calculate the required BaTiO3 powder quality, with BaTiO3 nanoscale powder and BaTiO3 submicron powder according to the ratio of mass ratio 1:1, add the prepared Ba in 25wt.% step 1 ( OH)2 / TiO2 suspension was ground in a mortar for 0.5-1h.

[0028] After cold pressing at room temperature for 15 minutes, keep the temperature at 200°C and keep the pressure for 3 hours, the pressure is 500MPa. BaTiO 3 The ceramic preform was dried at 200°C for 18 hours.

[0029] Carry out vacuum pr...

Embodiment 3

[0032] Ba(OH) 2 and TiO 2 The powder is put into the solvent (the solvent is deionized water) according to the molar ratio of 1.2:1, ultrasonically dispersed and stirred for 40min to obtain Ba(OH) 2 A suspension with a concentration of 0.1mol / L.

[0033] Select BaTiO with a purity of 99.99% and an average particle size of 40nm 3 Nanoscale powder and BaTiO with a purity of 99.9% and an average particle size of 500nm 3 Submicron powder. According to preparing BaTiO3 pottery and related device size, calculate the required BaTiO3 powder quality, with BaTiO3 nanoscale powder and BaTiO3 submicron powder according to the ratio of mass ratio 1:1, add the prepared Ba in 25wt.% step 1 ( OH)2 / TiO2 suspension was ground in a mortar for 0.5-1h.

[0034] After cold pressing at room temperature for 20 minutes, keep the temperature at 200°C and hold the pressure for 3 hours, the pressure is 450MPa. BaTiO 3 The ceramic preform was dried at 200° C. for 12 hours.

[0035] Carry out press...

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Abstract

The invention provides a low-temperature cold sintering preparation method of barium titanate ferroelectric ceramic. The preparation method comprises the following steps: 1, dissolving Ba(OH)2 and TiO2 into deionized water; 2, adding BaTiO3 nano-level powder and BaTiO3 submicron-level powder into 25 percent of Ba(OH)2/TiO2 suspension by weight prepared in the step 1 according to the mass ratio of 1 to 1, and carrying out grinding in a grinding bowl for 0.5 to 1 hour; 3, pouring BaTiO3 mixed slurry into a mold, carrying out cold pressing on an electric heating press in an environment with room temperature till the pressure is 450 to 500 MPa, preserving the pressure for 10 to 20 min, then under a condition of not changing the pressure, heating to 180 to 200 DEG C at the heating rate of 5 to 10 DEG C per minute, and preserving the temperature for 3 hours; 4, drying a BaTiO3 ceramic prefabricated blank at 200 DEG C for 12 to 18 hours; and 5, sintering the dried BaTiO3 ceramic prefabricated blank at 850 to 950 DEG C. The process is simple, environment-friendly and extremely low in energy consumption; the preparation method can be an ideal preparation method of the BaTiO3 ferroelectric ceramic for an underwater acoustic transducer, and has a wide industrial application prospect.

Description

technical field [0001] The invention provides a sintering preparation method of barium titanate ferroelectric ceramics. Background technique [0002] Ferroelectric ceramics have complex dielectric, piezoelectric, photoelectric and microwave absorption properties, and can be used in electronic and electronic industries, aerospace, underwater acoustic engineering and other fields. Barium titanate (BaTiO 3 ) is one of the most widely used ferroelectric ceramics. BaTiO 3 It is a typical perovskite structure (ABO 3 ) ferroelectrics have five different types of crystal structures in the temperature range below 1618°C, namely hexagonal, cubic, tetragonal, orthorhombic, and trigonal structures. at Curie temperature T c = At around 120°C, BaTiO 3 The phase structure changes from cubic phase to tetragonal phase, spontaneous polarization occurs (the polarization direction is along the c-axis direction), and it changes from paraelectric phase to ferroelectric phase, so it has exce...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/468C04B35/626
Inventor 王诗阳傅宇东朱小硕冷科
Owner HARBIN ENG UNIV
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