Dissertation > Excellent graduate degree dissertation topics show

Research on the Thermal Properties and Corrosion Resistance of Vacuum Sintering Nickel-based--Cermet Composite Coating with Rare Earth

Author: ZhangYi
Tutor: XuanTianPeng
School: Hefei University of Technology
Course: Materials Science
Keywords: vacuum fusion sintering Rare Earth element WC thermal wear resistance thermal fatigue resistance corrosion resistance
CLC: TG174
Type: Master's thesis
Year: 2007
Downloads: 139
Quote: 1
Read: Download Dissertation

Abstract


The Ni-based-WC with rare earth composite coating was obtained by the technique of vacuum sintering on the hypoeutectoid steel （Fe-0.45%C）. In virtue of SEM, X-ray diffraction and EDX, the microstructure and phase-structure of coating were investigated. This dissertation also studies that the active mechanism of rare earth element La and WC on microstructure and properties of vacuum sintering coating in the way of examining and evaluating in hardness, thermal wear resistance, thermal fatigue resistance and corrosion resistance of coating. The results show that with the appropriate addition of WC and rare earth element La, the microstructure, phases and properties of vacuum sintering Ni60A alloy coating change remarkably. Such change can be described as the followings. Firstly the microstructure of Ni-based alloy coating is composed of Ni-based solid solution and a lot of needle and massive phases. The metallurgical bonding between the matrix and coating has been realized. Secondly the microstructure of composite coating changes when WC is added in. The arborescent crystals of composite coating change to be fine and there are some massive WC phases appearing. Thirdly the composite coating adding rare earth element La makes needle phases reduced or vanished, microstructure changes to be smaller and uniform, and precipitate new phase, such as Cr5B3. Fourthly adding rare earth element La improves the state of bonding between the matrix and coating. The micro-hardness of transition area between the matrix and coating changes more mildly and the peak value of hardness appears in the coating side 0.40mm to interface. Fifthly the thermal wear resistance, thermal fatigue resistance and corrosion resistance of coating are enhanced obviously. Sixthly rare earth element La added in coating can raise the corrosion potential, reduce the corrosion current of the composite coating and enlarge the radius of capacitive arc obviously and increase the resistance of coating on the EIS. The corrosion resistance of coating is better in NaCl and NaOH solution but bad in acid. Influence of WC on corrosion resistance is very complex and need to be analyzed according to definite corrosion solution.

Related Dissertations

  1. Biological Effect of Rare Earth Element and Genetic Transformation on Arnebia Euchroma(Royle) Johnst.Cell,S567.239
  2. Research on Electrochemical Synthesis and Application of Conductive Polyaniline,O633.21
  3. WC / graphene composite electronic structure and electron transport properties,O613.71
  4. Electroless Ni-Pon the Bulk Nanocrystalline Ingot Iron,TQ153.1
  5. Study on Corrosion Resistance and Condensation Property of Ni-P/Nano SiO2 Composite Coatings,TG174.4
  6. The Study of Microstructure and Performance of La2 O3+CeO2-Ni-WC Composite Coating by Vacuum Fusion Sintering,TG174.44
  7. Preparation, Characterization and Performance of the Bio-coatings on the Surface of Pure Titanium Based on Micro Arc Oxidation,R318.08
  8. WC particle / high manganese -based composite surfacing layer microstructure and properties of,TG455
  9. Pulse Nanocomposite Coatings Preparation and Properties,TQ153
  10. Porcelain steel surface preparation in the lining layer of Technology,TG174.45
  11. Magnesium alloys and corrosion resistance of phosphating process,TG174.4
  12. Carbon steel liquid plasma electrolytic carbonitriding research,TG156.8
  13. ZA35 alloy elements Zr on Microstructure and Properties,TG131
  14. Medical magnesium alloy surface laser cladding Zr 60 Ti 6 Cu 19 Fe 5 Al 10 amorphous coating,TG174.44
  15. Prepared by pulsed electrodeposition Ti-based the lead composite electrode material and performance,TG174.4
  16. Study on the Ni-nWC Nano-Composite Coating by Electroplating,TG174.4
  17. Study on Preparation of the coarse-grained WC-Co cemented carbide,TG135.5
  18. Research of Technology and Properties of Laser Cladding on Ni/WC-Y2O3 Surface of 35CrMo Steel,TG174.44
  19. A Study on Microstructure and the Wear Resistant of Laser Cladding Ni/WC Composite Coating,TG174.44
  20. Investigation on Preparation of Graphene Oxide Supporting Catalysts and Their Catalytic Performance in Oxygen Reduction,O643.36
  21. Renewable carbide performance improvement and process optimization studies,TG135.5

CLC: > Industrial Technology > Metallurgy and Metal Craft > Metallurgy and Heat Treatment > Metal corrosion protection,metal surface treatment > Corrosion control and protection
© 2012 www.DissertationTopic.Net  Mobile