Dissertation > Excellent graduate degree dissertation topics show

Study on the Structure and Properties of Electrical Brush Planting Ni-P/Al2O3 Coating Aftering Heat Treatment

Author: QiaoJingHui
Tutor: ZhangJianXin
School: Hebei University of Technology
Course: Materials Science
Keywords: brush plating Ni-P/Al2O3 composite coating heat treatment coatingmicrostructure and properties
CLC: TQ153
Type: Master's thesis
Year: 2011
Downloads: 49
Quote: 0
Read: Download Dissertation

Abstract


The main forms of failure of materials are corrosion and wear. Nano-composite brushplated coatings can not only protect the surface of the substrate material, but also improve itswear and corrosion resistance. So nano-composite brush plating technique has far-reachingapplication. This paper is mainly concentrated upon fabricating Ni-P/Al2O3 compositecoatings on the Q235 steel substrate using brush plating method, determining the surfacemorphology of the composite coatings and investgating the effect of heat treatment to thestructure, wearing and corrosion resistance. The conclusions are summarized as follows:1. The surface morphology of Ni-P coatings is cell-like and uniform, but the surface ofNi-P/Al2O3 composite coatings shows uneven cauliflower-liked morphology. Obvious defectswere not found in the Ni-P/Al2O3 composite coatings which present a uniform thickness andtightly bonded to the substrate.2. Hardness, wearing and corrosion resistance of the Ni-P/Al2O3 composite coatings arebetter than those of Ni-P alloy coatings due to the addition of hard nanoparticles of Al2O3.3. The Ni3P phase in a small size is precipitated from Ni-P/Al2O3 composite coatingsafter the heat treatment of 300℃. The grain boundary has gradually become blurred after 450℃heat treatment, while the size of Ni3P grain becomes bigger, and the effect of dispersionstrengthening decreases after 500℃heat treatment.4. The Ni-P/Al2O3 composite coatings made in 30g/L Al2O3 solution are a mixture ofmicrocrystalline Ni-P solid solution and amorphous Ni-P. After 300℃ 450℃heat treatment,sharp peaks in the XRD pattern of the coatings confirm that in the coatings crystallization ofthe amorphous Ni-P has taken place. After 450℃600℃heat treatment, the main phases ofthe coatings are composed of the crystalline Ni-P and Ni3P, represented by their very sharpdiffraction.5. The hardness of the coatings is affected by the heat treatment. The coatings show a maximum hardness （HV1400） when the heat treatment temperature reached 450℃. All of thecoatings reached their highest hardness at 1h holding time for different heat temperature.6. The hardness, wearing resistance and binding strength of the Ni-P/Al2O3 compositecoatings are improved after heat treatment, while the corrosion resistance is reduced.

Related Dissertations

  1. Study on Key Technology and Its Physiological Basis of Virus Elimination and Rapid Propagation of Phalaenopsis,S682.31
  2. Study on the Subsurface Crack of Supporting Roller Made of Austempered Ductile Iron,TG156.3
  3. Thermophysics Research on Postharvest Spherical Fruit during Heat Treatment,S66
  4. The Research on Rolling and Heat Treatment Technology of AZ31 Magnesium Alloy Thin Sheet,TG166.4
  5. The Design and Implementation of Control System for Wire-steel Heat Treatment Direct-fired Furnace,TP273
  6. Study on Process Method and Parameter Optimization of the Remained-heat Treatment of Marine Heavy Forgings,TG316
  7. Study Continuous Glass Fiber Reinforced Polypropylene by Two-step Pultrusion,TQ327.11
  8. Study on the Preparation and Thermostability for Mechanical Properties Microstructure of Low Density MA/ ODS Nickel-Based Superalloy,TG132.32
  9. Study on the Spinnability of Semi-Aromatic Polyamide,TQ340.1
  10. Research on Numerical Simulation of Temperature Field of Cold-Rolled Pure Titanium Strip Coil during Annealing Process,TG156.2
  11. The Study Application of Induction Heat Treating Technology for Thick Walled Pipe,TM924
  12. Preparation of CuInS2 Photovoltaic Thin Films by Single Sourcevacuum Co-Evaporation,O484.1
  13. The Research on Production Technology, Microstructure and Mechanical Properties of AZ31 Magnesium Alloy Thin Sheet,TG339
  14. Research on the Preparation and Properties of Nano-particles Enhanced Brush Plating Ni-W-Co Composite Coatings,TB383.1
  15. Study on the Rechargeable Lithium Manganese Coin Cells,TM912.9
  16. Study on the Producing Technics and Thermal Properties of Glass-Ceramics in MgO-Al2O3-SiO2 System,TQ171.1
  17. Research on Multi-tungsten Alloy Plating,TQ153.2
  18. Study on the Corrosion Resistance of Ni-Sn-P Alloy Deposits,TQ153.2
  19. Preparation and Study of Glass-ceramics Based on Converter Slag,TQ171.1
  20. AZ31 Magnesium Alloy Electroless Ni-P Amorphous Plating and Its Crystallization,TG174.44
  21. Fea Analysis of Residual Stress for Heat Treatment of Oil Casing,TG156.3

CLC: > Industrial Technology > Chemical Industry > Electrochemical industries > Electroplating industry
© 2012 www.DissertationTopic.Net  Mobile