Preparation method of lead-free high-Curie-point BaTiO3-based positive-temperature-coefficient thermal sensitive ceramic

A technology of positive temperature coefficient, heat-sensitive ceramics, applied in high-tech functional ceramics and its application fields, can solve problems such as inaccurate chemical compounding, achieve low room temperature resistivity, ensure consistency and repeatability, and high Curie temperature Effect

Inactive Publication Date: 2017-06-20
CHINA UNIV OF GEOSCIENCES (BEIJING)
View PDF6 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the synthesis (Bi 0.5 Na 0.5 )TiO 3 In the process, due to Bi 2 o 3 The melting point is low (820 ℃), there will still be a part of volatilization, so the chemical composition of the prepared sample will be inaccurate,

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method of lead-free high-Curie-point BaTiO3-based positive-temperature-coefficient thermal sensitive ceramic
  • Preparation method of lead-free high-Curie-point BaTiO3-based positive-temperature-coefficient thermal sensitive ceramic
  • Preparation method of lead-free high-Curie-point BaTiO3-based positive-temperature-coefficient thermal sensitive ceramic

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0040] The invention provides a lead-free BaTiO with high Curie temperature, high lift-to-drag ratio and low room temperature resistivity 3 A positive temperature coefficient thermosensitive ceramic and a preparation method thereof, characterized in that the ceramic is made of tetragonal perovskite BaTiO 3 phase as the matrix, with (Bi 0.5 Na 0.5 )TiO 3 In order to increase the peak shifting agent of Curie temperature, the rare earth oxide Ta 2 O 5 or Sm 2 O 3 Reduce room temperature resistivity and add transition metal oxide MnO 2 to improve the lift-to-drag ratio; the preparation method adopts a one-pot method to prepare this lead-free BaTiO 3 Based on thermosensitive ceramics, and adopt the reduction-reoxidation sintering method to obtain BaTiO with excellent thermosensitive properties 3 Basic positive temperature coefficient thermosensitive ceramics; the preparation method sequentially includes the process method and steps of “weighing→mixing→ball milling→drying→ca...

Example Embodiment

[0053] Example 1: BaTiO of an example of the present invention 3 The manufacturing method and technological process of the basic positive temperature coefficient thermal ceramics are as follows:

[0054] (1) BaTiO with 91.2% mole fraction synthesized 3 powder, synthetic 8.8% (Bi 0.5 Na 0.5 )TiO 3 Powder, plus 0.3 mol% Ta 2 O 5 Powder, weigh BaCO 3 , TiO 2 , Bi 2 O 3 , Na 2 CO 3 and Ta 2 O 5 Powder reagents.

[0055] (2) Add all the reagents weighed in proportion to the ball mill tank of the planetary ball mill, and add 10 times the mass of ZrO 2 Milling balls and 5 times the mass of anhydrous ethanol solvent, ball milling for 6h.

[0056] (3) Dry the ground and mixed slurry in an atmospheric drying oven at a temperature of 80°C and a time of 72h.

[0057] (4) Put the ball-milled and dried mixed powder into a crucible, and then calcined in a muffle furnace at a temperature of 900°C and kept for 4h.

[0058] (5) The calcined composite ceramic powder is ground fi...

Example Embodiment

[0065] Example 2: BaTiO of an example of the present invention 3 The manufacturing method and technological process of the basic positive temperature coefficient thermal ceramics are as follows:

[0066] (1) BaTiO with 92% mole fraction synthesized 3 powder, synthetic 8% (Bi 0.5 Na 0.5 )TiO 3 Powder, plus 0.3 mol% Ta 2 O 5 powder and 0.04% mole fraction of MnO 2 Powder, weigh BaCO 3 , TiO 2 , Bi 2 O 3 , Na 2 CO 3 , Ta 2 O 5 and MnO 2 Powder reagents.

[0067] (2) adding all the reagents weighed in proportion to the ball milling tank of the stirring ball mill, and adding 10 times the mass of ZrO 2 Milling balls and 5 times the mass of anhydrous ethanol solvent, ball milling for 18h.

[0068] (3) Dry the ground and mixed slurry in an atmospheric drying oven at a temperature of 90°C and a time of 48h.

[0069] (4) Put the ball-milled and dried mixed powder into a crucible, and then calcine it in a muffle furnace at a temperature of 1000° C. and keep it warm for ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Grainaaaaaaaaaa
Room temperature resistivityaaaaaaaaaa
Curie temperatureaaaaaaaaaa
Login to view more

Abstract

The invention relates to a lead-free high-Curie-point BaTiO3-based positive-temperature-coefficient thermal sensitive ceramic, and a preparation method thereof, and belongs to the field of ceramic with high technological functions, and applications of the ceramic with high technological functions. According to the preparation method, tetragonal perovskite BaTiO3 phase is taken as a matrix, (Bi0.5Na0.5)TiO3 is taken as a peak moving reagent of Curie point, rare earth oxide Ta2O5 or Sm2O3 is used for reducing room temperature electrical resistivity, and transition metal oxide MnO2 is added to increase resistance increasing ratio; one pot reaction is adopted to prepare the lead-free BaTiO3-based thermal sensitive ceramic; reduction-reoxidation sintering is adopted to obtain the BaTiO3-based positive-temperature-coefficient thermal sensitive ceramic with excellent heat sensitive properties. The preparation method comprises following steps: weighing, material mixing, ball milling, drying, sintering, grinding and sieving, pelletizing, tabletting, hydrocarbon removing, sintering, and coating with electrode. The lead-free high-Curie-point BaTiO3-based positive-temperature-coefficient thermal sensitive ceramic is high in Curie point and resistance increasing ratio, low in room temperature electrical resistivity, contains no lead, and is especially suitable to be used for preparing parts used for heating protection, overtemperature protection, overcurrent protection, and temperature monitoring and sensing.

Description

technical field [0001] The invention relates to a lead-free high Curie temperature BaTiO 3 The invention relates to positive temperature coefficient heat-sensitive ceramics and a preparation method thereof, which belong to the field of high-tech functional ceramics and their applications. Background technique [0002] TiO 3 The positive temperature characteristic of the thermosensitive ceramic material based on positive temperature coefficient was discovered by Heywang et al. by doping a small amount of high-priced rare earth cations in barium titanate (Heywang W, et al.Journal of America Ceramic Society, 1964,47(10): 484-490). Composite positive temperature coefficient thermosensitive material with high expansion ceramic matrix, polymer matrix composite positive temperature coefficient thermosensitive ceramic material and V 2 o 3 , BaPbO 3 Based on positive temperature coefficient thermosensitive ceramic materials compared to BaTiO 3 Based on positive temperature coef...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C04B35/468
CPCC04B35/4682C04B2235/3201C04B2235/3224C04B2235/3234C04B2235/3251C04B2235/3267C04B2235/3298C04B2235/785
Inventor 彭志坚杨梦梦王成彪符秀丽
Owner CHINA UNIV OF GEOSCIENCES (BEIJING)
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap