Dissertation > Excellent graduate degree dissertation topics show

Study on Template Synthesis of Nano Tungsten Carbide Powders and Its Application in WC/Ni Composite Coatings

Author: WangLing
Tutor: ChenZhiGang
School: Jiangsu University
Course: Materials Science
Keywords: Porous carbonaceous material Nano Tungsten Carbide In situ reaction Flame spraying Laser remelting Wear resistance
CLC: TG174.44
Type: Master's thesis
Year: 2008
Downloads: 22
Quote: 0
Read: Download Dissertation

Abstract


This article explores the Nanometer WC powder, porous carbonaceous material as a template, tungstic acid and ammonia as raw materials, in situ synthesis of nano-WC powder. Heterogeneous precipitation nano WC particles the Ni wrapped, made of wrapped powder. Different content of nano-wrapped powder and micron-level WC powder mixed with F102 powder flame spray welding and laser remelting prepared WC / Ni composite coating, and the wear resistance of the coating. Different carbonaceous materials, W / C ratio, the holding time WC powder morphology and particle size. The results show that: the expanded graphite as carbon source, the reaction time is relatively long, In addition to WC and powder as well as a small amount of W 2 C the presence of carbon source prepared WC powder activated carbon can be used to do The body composition is relatively pure, the particle size is relatively small, approximately several tens of nanometers; When the W / C molar ratio of 1:2, and the product are of WC. When the holding time of 90min single product ingredients (activated carbon template), and powder dispersion, the particle size is relatively small, BET analysis showed that the particle size is 92 nm. And the experimental procedure of theoretical analysis, according to a conventional thermodynamic theory, can be calculated by Gibbs and greater than 1200K, and the reaction can proceed spontaneously, and the reaction is an endothermic reaction. Kinetic analysis showed that the reaction is diffusion-reaction. Discuss the preparation process of the organization and morphology of the coating. The results show that: the flame spray welding micron WC coating defects such as porosity nanodrugs WC coating less, and the particles are evenly distributed; After laser remelting coating becomes dense, but the micrometer WC / Ni coating the surface of a small amount of crack. Flame spray welding prepared nanometer WC / Ni coating and the two prepared micron level WC / Ni coating composition is similar to the main γ-Ni BNi 3 , WC, W < sub> 2 C, M , 6 C M 23 C 6 phase composition; nanoscale laser remelting WC / Ni coating constituent phases above Cr 4 Ni 15 W exist. WC particle size, add the amount of hardness and wear resistance of the composite coating. The results showed that when micron WC dosage 4vol.%, The hardness and wear resistance of the composite coating, the laser remelting to strengthen the hardness and abrasion resistance of the coating can be improved microns, and can be added micron WC amount to 6vol.%; when the nano WC added in an amount 6vol.% better wear resistance of the coating, laser remelting can effectively reduce the nano WC / Ni coating stomata, thereby improving the wear resistance. Under the same conditions WC Content, better than micron composite coating wear resistance of laser remelting of nano WC / Ni WC / Ni composite coating.

Related Dissertations

  1. Research and Development of Wear Resistance for Physically Disabled Men Jackets,TS941.2
  2. Preparation and Characterization of Ni-W Alloy and Ni-W/ T-1 Composite Coatings,TQ153
  3. Preparation and tribological properties of WC-Co-Ni carbide mold material,O313.5
  4. Carbon Nanotubes , purification and composite coatings research,TB383
  5. Investigation on Mechanical and Wear Properties of Alloy ZL108 Prepared with Electrolytic Low-Titanium Aluminum Base Alloy,O482.1
  6. Study on the Fabrication and Properties of Composite Chromium Plating,TG174
  7. Study on the Preparation and Properties of TiC Thin Films Deposited by the Multi-Arc Techniques,O484.4
  8. Development of Heat-resistant Ductile Cast Iron for Die Materials,TG255
  9. The Study on the Technology of Cr12 Mould Steel Laser Cladding,TG174.44
  10. The in situ synthesis of composite particles enhanced laser cladding of nickel-based layer,TG174.44
  11. The Property Study of Steel Mould Shaped Material by Arc Spraying,TG174.44
  12. Fabrication, Microstructure and Mechanical Properties of AZ81 Magnesium Matrix Composites Reinforced with SiC Particles,TB333
  13. Study on Parameter Optimization and Corrosion Resistance of Laser/plasma Remelting Plasma-sprayed Ni-coated WC Coatings,TG174.4
  14. Study of Microstructure and Properties of Plasma-sprayed NiCr-Cr3C2 Coatings Both before and after Remelting,TG174.442
  15. In Situ Synthesis of Al3Ti Particulate-Reinforced Aluminum Matrix Composites,TB331
  16. Micro structure and properties of in situ composites of Cu- nano TiB_2,TB383
  17. Preparation of C / C-SiC composites in situ reaction performance of friction and oxidation properties of,TB332
  18. Study on Arc Spraying Technology and the Performance of Spray Coat,TG174
  19. Research on the Technology、Structure and Performance of the Coating by Plasma Spraying,TG174
  20. Studies on Processes and Properties of Electrodeposited Ni-W-B Series Composite Coatings,TG174
  21. Study on Surface Precipitation Hardening Stainless Steel,TG174.4

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