Dissertation > Excellent graduate degree dissertation topics show

Low resistivity , high pressure barium titanate - based PTCR ceramic materials research and preparation

Author: LiYongFeng
Tutor: YangMengLin；ChangZhuGuo
School: Northwestern University
Course: Physical and chemical
Keywords: barium titanate PTCR ceramics Sol-gel method high performance
CLC: TQ174.6
Type: Master's thesis
Year: 2006
Downloads: 206
Quote: 1
Read: Download Dissertation

Abstract


For its unique resistivity-temperature characteristics, PTCR-barium titanate is now a common electrical device with many applications, such as degaussers in TV screens and computer monitors, self-regulated heaters, current suppressors, sensors, and automobiles （in each of which about 50 or 60 motors containing low-resistivity PTCR devices are used in door lock, power window, power seat, etc systems.）. The research of preparation of high performance BaTiO3-based PTCR ceramics with low room temperature resistivity, high ratio of lg(Rmax/Rmin), and high withstanding voltage has been a focal point in the field of inorganic nonmetal materials since the PTCR effect of doped barium titanate materials was discovered. The preparation and doping method influences the electrical properties of barium titanate strongly. Sol-gel method can prepare multicomposition barium titanate powders. To get high performance PTCR ceramics, Sol-gel method and China-made raw materials were used to prepare B-doped and Nb-doped barium titanate ceramics respectively. The effect of dopant and sintering process on the electrical properties of barium titanate ceramics were analysed by TG-DSC analysis and SEM photoes.This MD dissertation is divided into three parts.In part 1, boron-doped barium titanate ceramics was prepared by Sol-gel method, and the effect of Boron content and sintering temperature on electrical properties and microstructure was investigated. The results show that not only its sintering temperature can be lowered, but also the withstanding voltage can be improved largely.In part 2, Double-donor Nb,Y-codoped barium titanate ceramics was prepared by Sol-gel method with H3[Nb（O2）4] as raw materials, and the effect of Niobium content and cooling rate on electrical properties and microstructure was investigated. The results show that high performance PTCR ceramics could be obtained by the optimization of the content ratio of Nb/Y.In part 3, high performance BaTiO3-based PTCR ceramics for refrigerator motor starter was prepared by sol-gel method. Based on the optimized composition, 5molPTCR ceramics powders for refrigerator motor starter was prepared. The orthogonal experiment was successfully used to design and optimize the sintering process, and the influence of sintering factors on ceramics materials was discussed by the orthogonal experiment.

Related Dissertations

  1. Study on the Synthesis Bi3.25La0.75Ti3O12（BLT） Nanotubes and Nano Wires,TB383.1
  2. Development of Pxibus High Performance Digital I/O Module,TP274
  3. Synthesis and Resolution Property of N-(9-Fluorenylmethoxycarbonyl)-D-Tryptophan and D-Phenylalanine Imprinted Polymer,O631.3
  4. The Study on Rhinoceros Horn and Its Imitation,TS932.2
  5. Research on Melamineanalysis Method in Milk Powder and Establish the System of Rapid Determination,O657.3
  6. Fast Determination Method Research of Bisphenol A in Food Packing Material,TS206.4
  7. Analysing Sequence Characters of ADSL and PurH Gene and Correlation between Genes Expression and IMP Content in Duck,S834
  8. A Role of Auxin in Repression of Harpin-Induced Hypersensitive Response in Tobacco,S432.1
  9. Study on Synthesis of Polysaccharide Tris (Phenylcarbamates) Derivatives as Chiral Stationary Phases (CSPs) and Estimation of Their Resolution Abilities,TQ460.1
  10. Synthesis and Quality Control Research of ATPR,TQ463
  11. Study on Synthetic of BINOL, Amino Acid and Derivatives Molecularly Imprinted Polymers and Their Application in the Chiral Resolution,O631.3
  12. Optimization of Extraction of Gastrodin from Rhizoma Gastrodia by Response Surface Methodology,R284.1
  13. The Fingerprints Establishment and Preliminary in Vitro Metabolism of Shuanghuanglian Powder-Injection and Oral-Liquid,R286
  14. Chinese medicines by high performance liquid chromatographic fingerprints and non-linear chemical fingerprint of,R284
  15. The Evodia medicine quality, pharmacokinetics and tissue distribution studies,R284
  16. Study on the Production of Polycyclic Aromatic Hydrocarbons in "Peking Roast Duck" with Air-jet Impingement Roasting Technique,TS251.67
  17. Research on the Change of Tea Polyphenols Content in Different Growing Period of Tea Leaves,TS272.7
  18. Determination of Phenolic Antioxidants in Fried Food by Hplc,TS207.3
  19. The New Reinforcing Bar Net Reinforces the Research of Material,TU528
  20. Determination of Catecholamines and Nitroanilines Using High-performance Liquid Chromatography Combined with Solid-phase Extraction,O657.72
  21. The synthesis of NZP family mesoporous phosphate materials,O643.36

CLC: > Industrial Technology > Chemical Industry > Silicate > Ceramic Industry > Production process and equipment
© 2012 www.DissertationTopic.Net  Mobile