Dissertation > Excellent graduate degree dissertation topics show

Toughening Piezoelectric Ceramics

Author: JinDaZhong
Tutor: ChenXiangMing
School: Zhejiang University
Course: Materials Science
Keywords: Piezoelectric ceramic Coarse particles Fracture toughness Grain size distribution Toughening mechanism Situ growth Large grains Dosage Composite structure Piezoelectric properties
CLC: TQ174
Type: Master's thesis
Year: 2002
Downloads: 229
Quote: 4
Read: Download Dissertation

Abstract


This paper presents a novel piezoelectric ceramic toughening methods - large grains dispersed situ toughened composite structure. That the piezoelectric ceramic body of coarse particles added to the same components forming such micro-structure to lower the piezoelectric performance without the premise, significantly improve the fracture toughness. In this thesis, this new approach were investigated PZT, BaTiO 3 and (Bi 1/2 Na 1/2 ) TiO 3 -based piezoelectric ceramics toughened, and the growth of large grains dispersed in situ fracture toughness of the ceramic composite structure of the theoretical analysis. Of the PZT piezoelectric ceramic, adding coarse particles of grain size distribution broadening, but without changing the PZT ceramics intergranular fracture mode, large grain boundaries are the main dissociation toughening mechanism. Fracture toughness with the increase of the amount of coarse particles and significant improvement in the amount of coarse particles are added 15wt.% When K IC reached its maximum 1.43MPa · m 1/2 . The dielectric constant ε T 33 / ε o with increase of the amount of coarse particles and slightly increased, other piezoelectric performance is almost constant. In BaTiO 3 piezoelectric ceramic, sintering the obtained coarse particles added to a wide grain size distribution. BaTiO 3 ceramic fracture mode was mainly transgranular fracture, micro-cracks are the main toughening mechanism. Fracture toughness with the increase of the amount of coarse particles and significant improvement in the amount of coarse particles are added 15wt.% When K IC reached its maximum 1.97MPa · m 1/2 , and fracture toughness of the matrix is ??only 1.14MPa · m 1/2 . The introduction of coarse particles hardly changes piezoelectric properties. In the (Bi 1/2 Na 1/2 ) TiO 3 ceramics, sintering time was significantly prolonged promoted (Bi 1 / 2 Na 1/2 ) TiO 3 ceramic grain size increased and the (Bi 1/2 Na 1/2 ) TiO 3 ceramics fracture toughness, K IC reached the maximum 1.81 MPa · m 1/2 . Adding coarse particles of grain size distribution broadening. Fracture toughness with the increase in the amount of coarse particles while adding significant improvement in the amount of coarse particles added 10wt.% When K IC reached the maximum 1.91MPa · m 1/2 . (Bi 1/2 Na 1/2 ) TiO 3 , the fracture pattern is typical of transgranular fracture, micro-cracks are the main growth toughening mechanism of porosity on fracture toughness has a great negative impact. Increasing the grain size to improve the mechanical quality factor Q m , permittivity ε T 33 / ε o , and electrical dielectric loss tanδ coupling coefficient k p , reducing the frequency constant N p , pores on the fracture toughness and piezoelectric properties and grain size of the opposite. Introduction of coarse particles (Bi 1/2 Na 1/2 ) TiO 3 ceramic piezoelectric properties change little. In PZT, BaTiO 3 and (Bi 1/2 Na 1/2 ) TiO 3 ceramics found situ dispersion having a large grain structure of the piezoelectric ceramic composite fracture toughness of the same average grain size of the microstructure of a conventional case even greater. Application of micro-cracks and grain boundary toughening mechanism of dissociation model theoretically proved situ with diffuse large grains of the ceramic composite structure with the same grain size than conventional micro-structural ceramics greater crack resistance, calculated values in good agreement with the experimental values.

Related Dissertations

  1. Technology of Filling Clearance and Optimizing the Bonds during Ultrasonic Brazing,TG454
  2. Research of Predictive Control in Water Treatment Plant Based on Neuron Network,TP273.1
  3. Mineralogical and Geochemical Evidence of the Presence of Ancient Paddy Soil Layer in Chuodun Ancient Agricultural Site, Kunshan,S-09
  4. Study on Low Temperature Sintered PSN-PZT Piezoelectric Ceramics,TM282
  5. Medical ultrasound imaging Piezoelectric transducer probe studies,TN384
  6. The Development of the Interference Testing System for Optical Fiber Connector Surface,TN253
  7. AVIC International Plaza Building, structural stability analysis,TU973.2
  8. ARM-based control system for large stroke precision stage,TP273
  9. Based on the voltage control mode of a millimeter wave magnetron tuning,TN123
  10. Research on Durability Evaluation Method of Cement Concrete Pavement,U416.216
  11. Study on the Coagulation Pretreatment of Municipal Wastewater and Anaerobic Digestion of the Chemical Sludge,X703
  12. Flocculation and Filter Experiment of Effluent from T6 Tube,X703
  13. Advanced Treatment on Tail Water from Municipal Wastewater Treatment Plant by Modified Diatomite,X703
  14. Research on Antibacterial Fabric Design and Development of Silver-plated Fiber,TS195.6
  15. Properties of 1-3 Polymer/Cement Based Piezoelectric Composites,TB332
  16. Influence of Rubber Aggregate Mixing Amount and Gradation on Concrete Properities,TU528.041
  17. The Research on PZN-PLZT Piezoelectric Ceramics with High Properties,TM282
  18. Research of Nonlinear Dynamic Characteristics and Control for Laminated Beam with Piezoelectric Ceramic,TM282
  19. Low Voltage Driving Ultrasonic Motors Based on Multilayer Piezoelectric Ceramics,TM359.9
  20. Aircraft reinforced slab structure piezoelectric Active / Passive Control System,V227
  21. Implanted under pure shear load component composite laminate failure research,V229.7

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