Method for increasing bismuth layer structure piezoelectricity ferroelectric ceramic material density

Abstract

The invention discloses a density enhancing method of piezoelectric ferroelectric ceramic materials with bismuth layer structure. According to a chemical formula: (Am-1BmO3m+1) <2-> (Bi2O2) <2+>; and molar ratio A: B: Bi = m-1: m : 2, materials are calculated and weighted, wherein, the A is univalent, bivalent, trivalent or quadrivalent metal ion that is suitable for dodecahedral coordination; the B is trivalent, quadrivalent, pentavalent or sexivalent metal ion that is suitable for octahedral coordination; the production processes are that: mixing, pre-synthesizing, grinding, forming and sintering; the sintering process is that: the temperature of the obtained material from the last step is raised to 1100 to 1250 DEG C at a speed of 2 to 5 DEG C per minute, and is lowered to 50 to 150 DEG C within 1 to 5 minutes; under the temperature of 950 to 1150 EDG C, insulation at the low temperature is done for 5 to 20 hours; then the temperature is lowered to 500 DEG C at a speed of 3 to 7 DEG C per minute, and the obtained material is naturally cooled with a furnace. The invention can obtain the piezoelectric ferroelectric ceramic materials with grain-refining and density bismuth structure.

Description

technical field

[0001] The invention relates to a functional ceramic material, in particular to a method for increasing the density of a bismuth layer-structured piezoelectric ferroelectric ceramic material. Background technique

[0002] Bismuth-structured ferroelectric materials (BLSF) are a class of potential high-temperature lead-free piezoelectric ferroelectric materials, which have high Curie temperature and quality factor, large anisotropy, high dielectric strength and resistivity, Due to the characteristics of high breakdown strength and low aging rate, the research and development of piezoelectric ferroelectric materials with bismuth layer structure are very active in recent years.

[0003] The general chemical formula of bismuth layer structure ferroelectric material is (A m-1 B m o 3m+1 ) 2- (Bi 2 o 2 ) 2+ Represented by the perovskite-like layer (A m-1 B m o 3m+1 ) 2- with (Bi 2 o 2 ) 2+ The layers are regularly arranged alternately along the c-axis....

Examples

Embodiment 1

[0024] Sr with m=4 0.3 Ba 0.7 Bi 4 Ti 3.95 V 0.05 o 15 For the base formula, the molar ratio Sr: Ba: Bi: Ti: V = 0.3: 0.7: 4: 3.95: 0.05 ingredients, the raw materials used are analytically pure strontium carbonate (SrCO 3 ), barium carbonate (BaCO 3 ), bismuth oxide (Bi 2 o 3 ), titanium oxide (TiO 2 ), vanadium oxide (V 2 o 5 ).

[0025] Calculate and weigh raw materials according to the formula. Using distilled water as the ball milling medium, use a planetary ball mill for 2 hours, dry at 120°C, and pass through an 80-mesh sieve. Then the mixture was sealed and pre-fired at 800°C for 2 hours. After crushing the pre-fired powder for 4 hours, dry it at 120° C. and pass through a 80-mesh sieve. Pre-compress the powder with a pressure of 10MPa, and then press the powder into a disc with a diameter of 15mm and a thickness of 2mm with a cold isostatic press under a pressure of 250MPa, and hold the pressure for 1min.

[0026] The shaped discs are sealed and sintere...

Embodiment 2

[0032] SrCaBi with m=5 4 Ti 5 o 18 For the base formula, the molar ratio Sr: Ca: Bi: Ti = 1: 1: 4: 5 ingredients, the raw materials used are analytically pure strontium carbonate (SrCO 3 ), calcium carbonate (CaCO 3 ), bismuth oxide (Bi 2 o 3 ), titanium oxide (TiO 2 ).

[0033] Calculate and weigh raw materials according to the formula. Using distilled water as the ball milling medium, use a planetary ball mill for 2 hours, dry at 120°C, and pass through an 80-mesh sieve. Then the mixture was sealed and pre-fired at 900°C for 4 hours. After crushing the pre-fired powder for 4 hours, dry it at 120° C. and pass through a 80-mesh sieve. Pre-compress the powder with a pressure of 20 MPa, and then press the powder into a disc with a diameter of 15 mm and a thickness of 2 mm with a cold isostatic press under a pressure of 300 MPa for a holding time of 20 s.

[0034] The shaped discs are sealed and sintered in a muffle furnace. The sintering is carried out in stages: firs...

Embodiment 3

[0037] Bi with m=3 3 LaTi 3 o 12 It is base formula, by molar ratio Bi: La: Ti=3: 1: 3 batching, used raw material is the bismuth oxide of analytical grade (Bi 2 o 3 ), lanthanum oxide (La 2 o 3 ), titanium oxide (TiO 2 ).

[0038] Calculate and weigh raw materials according to the formula. Using distilled water as the ball milling medium, use a planetary ball mill for 2 hours, dry at 120°C, and pass through an 80-mesh sieve. Then the mixture was airtightly calcined at 850°C for 3 hours. After crushing the pre-fired powder for 4 hours, dry it at 120° C. and pass through a 80-mesh sieve. Pre-compress the powder with a pressure of 5 MPa, and then press the powder into a disc with a diameter of 15 mm and a thickness of 2 mm with a cold isostatic press under a pressure of 150 MPa, and hold the pressure for 2 minutes.

[0039] The shaped discs are sealed and sintered in a muffle furnace. The sintering is carried out in stages: first, the temperature is raised to the high...

technical field

[0001] The invention relates to a functional ceramic material, in particular to a method for increasing the density of a bismuth layer-structured piezoelectric ferroelectric ceramic material. Background technique

[0002] Bismuth-structured ferroelectric materials (BLSF) are a class of potential high-temperature lead-free piezoelectric ferroelectric materials, which have high Curie temperature and quality factor, large anisotropy, high dielectric strength and resistivity, Due to the characteristics of high breakdown strength and low aging rate, the research and development of piezoelectric ferroelectric materials with bismuth layer structure are very active in recent years.

[0003] The general chemical formula of bismuth layer structure ferroelectric material is (A m-1 B m o 3m+1 ) 2- (Bi 2 o 2 ) 2+ Represented by the perovskite-like layer (A m-1 B m o 3m+1 ) 2- with (Bi 2 o 2 ) 2+ The layers are regularly arranged alternately along the c-axis....

Examples

Embodiment 1

[0024] Sr with m=4 0.3 Ba 0.7 Bi 4 Ti 3.95 V 0.05 o 15 For the base formula, the molar ratio Sr: Ba: Bi: Ti: V = 0.3: 0.7: 4: 3.95: 0.05 ingredients, the raw materials used are analytically pure strontium carbonate (SrCO 3 ), barium carbonate (BaCO 3 ), bismuth oxide (Bi 2 o 3 ), titanium oxide (TiO 2 ), vanadium oxide (V 2 o 5 ).

[0025] Calculate and weigh raw materials according to the formula. Using distilled water as the ball milling medium, use a planetary ball mill for 2 hours, dry at 120°C, and pass through an 80-mesh sieve. Then the mixture was sealed and pre-fired at 800°C for 2 hours. After crushing the pre-fired powder for 4 hours, dry it at 120° C. and pass through a 80-mesh sieve. Pre-compress the powder with a pressure of 10MPa, and then press the powder into a disc with a diameter of 15mm and a thickness of 2mm with a cold isostatic press under a pressure of 250MPa, and hold the pressure for 1min.

[0026] The shaped discs are sealed and sintere...

Embodiment 2

[0032] SrCaBi with m=5 4 Ti 5 o 18 For the base formula, the molar ratio Sr: Ca: Bi: Ti = 1: 1: 4: 5 ingredients, the raw materials used are analytically pure strontium carbonate (SrCO 3 ), calcium carbonate (CaCO 3 ), bismuth oxide (Bi 2 o 3 ), titanium oxide (TiO 2 ).

[0033] Calculate and weigh raw materials according to the formula. Using distilled water as the ball milling medium, use a planetary ball mill for 2 hours, dry at 120°C, and pass through an 80-mesh sieve. Then the mixture was sealed and pre-fired at 900°C for 4 hours. After crushing the pre-fired powder for 4 hours, dry it at 120° C. and pass through a 80-mesh sieve. Pre-compress the powder with a pressure of 20 MPa, and then press the powder into a disc with a diameter of 15 mm and a thickness of 2 mm with a cold isostatic press under a pressure of 300 MPa for a holding time of 20 s.

[0034] The shaped discs are sealed and sintered in a muffle furnace. The sintering is carried out in stages: firs...

Embodiment 3

[0037] Bi with m=3 3 LaTi 3 o 12 It is base formula, by molar ratio Bi: La: Ti=3: 1: 3 batching, used raw material is the bismuth oxide of analytical grade (Bi 2 o 3 ), lanthanum oxide (La 2 o 3 ), titanium oxide (TiO 2 ).

[0038] Calculate and weigh raw materials according to the formula. Using distilled water as the ball milling medium, use a planetary ball mill for 2 hours, dry at 120°C, and pass through an 80-mesh sieve. Then the mixture was airtightly calcined at 850°C for 3 hours. After crushing the pre-fired powder for 4 hours, dry it at 120° C. and pass through a 80-mesh sieve. Pre-compress the powder with a pressure of 5 MPa, and then press the powder into a disc with a diameter of 15 mm and a thickness of 2 mm with a cold isostatic press under a pressure of 150 MPa, and hold the pressure for 2 minutes.

[0039] The shaped discs are sealed and sintered in a muffle furnace. The sintering is carried out in stages: first, the temperature is raised to the high...

Images