Dissertation > Excellent graduate degree dissertation topics show

Preparation and tribological properties of WC-Co-Ni carbide mold material

Author: LiGuoLin
Tutor: GuoShaoYi
School: Zhejiang University of Technology
Course: Mechanical Design and Theory
Keywords: cemented carbide fricition coefficient wear-resistance friction and wear wear mechanism
CLC: O313.5
Type: Master's thesis
Year: 2010
Downloads: 136
Quote: 0
Read: Download Dissertation

Abstract


With rapid development of die & mold industry, the requirement for performance of die materials is higher and higher. Cemented carbide is used widely in the field of die machining because of its excellent hardness and wear-resistance. But with the speed of material molding rising, the requirement for cemented carbide performance must be improved. Therefore, the research and development of high-performance cemented carbide has importantly realistic significances.Nano-composites powder was made by high energy ball mill and then tungsten carbide with different binder content was prepared by sintering-HIP. The microstructure of prepared tungsten carbide samples was observed and compared by metallurgical microscope and SEM; the main mechanical properties of them were tested; the relationship among composition and microstructure and performance of them was studied and analyzed. Considering the special requirements of wear-resistance of die materials, the focus was on doing systemic friction-wear tests of prepared samples and studying the relationship between wear-resistance and composition of them. The worn surface of samples was observed and studied; then wear mechanisms and their affective factors and rules of tungsten carbides with different tribological property were discussed and analysed.The results showed that the content of cement (Co and Ni) of tungsten carbide would affect its microstructure, tribological property and wear mechanism directly. The sample with 19.5% content of cement had even microstructure, its wear-resistance best and its wear mechanism mainly adhesive wear; the sample with 7.5% content of cement had uneven microstructure, its wear-resistance worst and its wear mechanism mainly abrasive wear and brittle exfoliate. The wear mechanism of WC based cemented carbide varied with content of cement changing, high content of cement mainly adhesive wear while low content of cement mainly abrasive wear. The main reason of different wear-resistance of them was the different wear mechanism. Abrasive wear resulted worse wear-resistance.In identity condition, with the sliding speed rising the friction coefficient reduced and the wear rate increased. With the load rising, the friction coefficient of cemented carbide with less cement increased. But for the tungsten carbide with more cement, the friction coefficient varied complexly. That is because the wear mechanism changed with load increasing. The wear rate increased as the load increasing. But the content of cement could change the wear rate of tungsten carbide obviously, the main reason being different wear mechanism. The result also showed that the friction coefficient was affected with different fiction pair. The friction coefficient of friction pair WC-Co-Ni/Si3N4 was higher than WC-Co-Ni/GCr15 obviously.

Related Dissertations

  1. Reactive Hot-Pressing and Mechanical Properties of （ZrB2-ZrO2）/BN Composites,TB332
  2. Research on Technology and Mechanism of Joining Cemented Carbide to Carbon Steel,TG454
  3. Research and Development of Wear Resistance for Physically Disabled Men Jackets,TS941.2
  4. Study on Technics & Performance of Nano Electroless Composite Plating on 20~# Steel,TQ153
  5. Preperation of Low Friction and Wear Resistant High-Purity Alumina Ceramic,TQ174.1
  6. Magnesium alloy surface MoS2 / resin hybrid layer Preparation and Properties,TG174.4
  7. Repeated upsetting suppress Mg-Si alloys prepared microstructure and properties,TG146.22
  8. Endogenous iron-based composites and tribology research,TB331
  9. Valve material surface modification layer prepared a variety of techniques Study,TG174.44
  10. NiTi alloy coated stainless steel surface preparation,TG174.44
  11. Carbon fiber reinforced PEEK composite materials and their friction and wear properties,TB332
  12. Situ (Ti, W) C particle reinforced steel matrix composites and organizational performance research,TB331
  13. Microstructures and Performance of Plasma Cladding High-Chromium Iron-Base Wear Resistant Coating by the Precursor Carbonization-Composition Process,TG174.4
  14. Surface Modification of AZ31 Magnesium Alloy and Pure Titanium by High Current Pulsed Electron Beam,TG166.4
  15. Study on Non-slag Wear Resistance Surfacing Electrode with Lron Powder and Welding Process,TG422.1
  16. Anode Milling Tool Wear Analysis and Determination of Tool Life,TG54
  17. Study on Preparation of the coarse-grained WC-Co cemented carbide,TG135.5
  18. Cu/QCr0.5 carrier friction and wear properties under study,TG115.58
  19. AC austenitic stainless steel surface pretreatment studies with low-temperature plasma nitriding,TG156.82
  20. The in situ synthesis of composite particles enhanced laser cladding of nickel-based layer,TG174.44
  21. Tribological Properties and Corrosion Resistance to Molten Steel of （ZrB2-ZrO2）/BN Composites,TB332

CLC: > Mathematical sciences and chemical > Mechanics > Theoretical Mechanics ( general mechanics ) > Dynamics > Friction theory
© 2012 www.DissertationTopic.Net  Mobile