Dissertation > Excellent graduate degree dissertation topics show

The Sintering Process and Mechanical Properties of Zirconia/Calcium Phosphate Compound Ceramic

Author: WangYang
Tutor: WangFuPing
School: Harbin Institute of Technology
Course: Chemical Engineering and Technology
Keywords: dental ceramics sintering process mechanical properties calcium phosp
CLC: R783.1
Type: Master's thesis
Year: 2012
Downloads: 25
Quote: 0
Read: Download Dissertation


Now the civil independent dental ceramic materials production is still in itsinfancy,so most of the raw materials are needed to be imported abroad. Themachinable dental ceramics that made by our country have many defects,low flexuralstrength,bad toughness and the hardness is too high.The composite ceramic in this studyis prepared by doping calcium phosphate which has high biocompatibility in zirconiamatrix.After sintering,we will get machinable composite ceramics.The calcium phosphate powders were prepared by the sol-gel technology.,mixphosphate powder with the zirconia powder,then after optimization of the sinteringprocess,the zirconia/calcium composite ceramics are prepared.After studyingmechanical properties of the composite ceramics prepared and analyzing the factorsaffect,we got that the most important sintering process was the sintering temperature.Atdifferent sintering temperatures,there always the monoclinic phase of zirconia andtetragonal zirconia exist in the composite ceramics.And the cubic solid solutionc-Ca0.15Zr0.85O1.85will appear in the sintering at1400℃.At the same time,we shouldtest the fracture of the ceramic composite and show the microstructure by scanningelectron microscopy.Then it can be proved that the main fracture mode of ceramiccomposite are transgranular fracture and intergranular fracture,when the sinteringprocess is appropriate,transgranular fracture is the main.Some sintering processes like holding time, heating rate and calcium phosphate contentalso have important effects on the mechanical properties.Holding time and thecomposite ceramic heating rate mainly affect the density of the porosity and grainsize,therefore, the appropriate holding time and heating rate is very important on themechanical properties of composite ceramics.The content of calcium phosphate directlyaffects the mechanical properties of composite ceramics,the mechanical properties ofceramic composite linear increase with the reduction of calcium phosphate.But whenthe content of calcium phosphate is too low,the hardness of the ceramic composite willbe higher than the hardness of dental ceramics,so we need to select the content ofcalcium phosphate comprehensively.After the test it is proved that when the sinteringtemperature is1350℃, the holding time is4h,the heating rate of2.5°C/min and theincorporation of calcium phosphate is35%, we will get to the best effect. The sintering of composite ceramic can be calculated by the calculation of the sintering activationenergy of composite ceramic,it is very important for making the sintering curve.Besideswe analyzed the mass transfer mechanism of composite ceramic sintering process basedon it, the macroscopic is mobile mass transfer and diffusion mass transfer,themicroscopic is atomic diffusion and ion diffusion.In the best sintering process,themechanical properties of Composite material is549MPa of the bendingstrength,140GPa of the elasticity modulus,9.1MPa.m1/2of the fracture toughness,and8.5GPa of the hardness,which are in line with the requirements of ceramics on themechanical properties.

Related Dissertations

  1. Reactive Hot-Pressing and Mechanical Properties of (ZrB2-ZrO2)/BN Composites,TB332
  2. Research on Welding Characteristics of CO2 Laser-GMA Hybrid Welding for Ultra-Low Carbon Bainitic Steel,TG456.7
  3. Microstructure and Mechanical Properties of Mg-Zn-Y-Zr Alloys,TG146.22
  4. Fabricationand Properties of SiC-AlN Multiphase Ceramics Prepared by Gelcasting,TQ174.62
  5. Synthesis of Polysulfones and Modification for Epoxy Adhesives,TQ433.437
  6. Research on Mechanical Properties of Concrete with Multi-Component Admixture,TU528
  7. Preparation and Properties of Reinforcements/ Polyacrylonitrile Composite Nanofibers,TB383.1
  8. Research on Pre-wetting Sizing and Its Influence on the Quality of Cotton Yarns,TS105.213
  9. Structure and Characterization of Room Temperature Self-crosslinked Acrylonitrile-butadiene-styrene,TQ325.2
  10. The Research on Extrusion Parameters Through the Plate Billet of Magnesium Alloy,TG379
  11. Study on the Mechanical Properties of Short Cut Aramid Fiber Reinforced Cement Mortar Composites,TU578.1
  12. Study on Influence of Preferred Orientation on Mechanical and Recoverable Properties of TN479 Shape Memory Alloy Sheet,TG139.6
  13. Research on End-Effector of Citrus Harvesting Robot,TP242
  14. Study on Microstructure and Performance of Laser Cladding Ni-Based Amorphous Alloy Coatings,TG174.4
  15. Study on the Modification of Basalt Fiber Composites Used for Wind Turbine Blades,TB332
  16. Study on Extrusion and Heat Treatments of AJ and AE Series Cast Magnesium Alloys,TG166.4
  17. Analysis and Research on Organizational Field and Mechanical Properties of Hot-rolled H-beam in the Controlled Cooling Process,TG335
  18. The Deformation Law and Its Influnecing Factors of Iron-based Valve Plate in Sintering Process,TF124.5
  19. Research on Organization and Performance of 490MPa Grade Fire-resistant Steel,TG142.73
  20. Study of Internal Friction on Masteel’s Automotive Sheets of a Series of Steels,U465.11
  21. The Experimental Study of Mechanical Properties of HTS Tapes,TM26

CLC: > Medicine, health > Oral Sciences > Oral orthotics > Dental Materials Science
© 2012 www.DissertationTopic.Net  Mobile