Authors
1 Semi-Conductors department, Materials and Energy Research Center, Karaj, Iran
2 Shetabkar unit4 Co., Tehran, IRAN
3 Semi-Conductors department, Materials and Energy Research Center, Karaj, IRAN
Abstract
Producing of today cutting tools without cemented carbides as a raw material is impossible. Requirements of industries to new cutting tools with high quality and performance in order to achieving better economical results, was caused to use of advanced processes in producing and improving of these tools. In this research, it is endeavored by changing sintering time, new properties and broadened fields of cemented carbide tools are obtained. For this purpose, samples of “K” type standard with WC(92%Wt), TaC(2%Wt) and Co(6%Wt) composition and “P” type standard with WC(80%Wt), TaC(5%Wt), TiC(5%Wt) and Co(10%Wt) composition which are suitable for cast iron and steel machining respectively, were processed. Microstructure of raw materials and products were investigated by light and scanning electron microscopy respectively. Samples were sintered at 1490±5°C for 1 to 10 hours in a 10-2torr vacuumed electric furnace. Analyzing of XRD patterns by software revealed desirable phases. Mechanical properties were analyzed by measuring of hardness changing from 1698HV30 to 1674HV30 for “K” type and 1389HV30 to 1347HV30 for “P” type samples. Transverse rupture strength of samples was measured after 4hr sintering and an increasing revealed up to 2991MPa for “K” type and 2710MPa for “P” type samples because of elimination of crack formation centers and after that decreased to 2610MPA and 2250MPa because of predominant of grain growth phenomenon, respectively. Also measurements of magnetic saturation and coercive force properties were done on sintered samples, which revealed reduction in both of these properties by increasing sintering time. No changing in density was observed.
Keywords
- Lammerman, H., and Kienel, G., PVD Coating for Aircraft Turbine Blades, Advanced Mat. And Processes, pp. 18-23 (Dec. 1991)
- Longo, F., Thermal Spray Coatings Market, Trends, and Forecast, Thermal Spray Conf., Gorham Advanced Mat. Inst., Gorham, ME (1992)
- Rohde, S. L., Sputter Depositio, in ASM handbook, Vol. 5, Surface Engineering, pp. 573-581, ASM Publ. (1994)
- Singer, P., 1995: Looking Down the Road to Quarter-Micron Production, Semiconductor International, pp. 46-52 (Jan. 1995)
- Sims, C. T., Non-Metalic Materials for Gas-Turbine Engines, Advanced Mat. And Processes, pp. 32-39 (June 1991)
- Ralf Riedel, HANDBOOK OF CERAMIC HARD MATERIALS, WILEY-VCH, New York, 2000, pp. XL VI
- Hugho O. Pierson, HANDBOOK OF REFRACTORY CARBIDES AND NITRIDES, Properties, Characteristics, Processing and Applications, NOYES PUBLICATIONS, Westwood New, Jersey, U.S.A.,1996, pp. 69
- KARIN MANNESSON, WC grain growth during sintering of cemented carbides, Experiments and simulations, Doctoral Thesis, Stockholm, Sweden 2011
- Oladapo Eso, Zhigang Zak Fang, Anthony Griffo , Kinetics of cobalt gradient formation during the liquid phase sintering of functionally graded WC–Co, International Journal of Refractory Metals & Hard Materials 25 (2007) 286–292, ELSEVIER
- Gopal S. Upadhyaya, CEMENTED TUNGSTEN CARBIDES, Production, Properties, and Testing, Section 8, 1998, ISBN: 0-8155-1417-4, NOYES PUBLICATIONS
- Seyed Ali Tayebifard, Training Course Manual, Non-Oxide Engineering Ceramics, Material & Research Center, Sep. 2012
- X’Pert HighScore Plus, Version: 2.2b (2.2.2) Date: 01-11-2006, Produced by: PANalytical B.V. Alemo, The Netherlands
- S. Upadhyaya, Materials science of cemented carbides _ an overview, Materials and Design 22 (2001), 483-489
- Hwan Cheol Kim a, In Kyoon Jeong a, In Jin Shon a,*, In Yong Ko a, Jung Mann Doh, Fabrication of WC–8 wt.%Co hard materials by two rapid sintering processes, International Journal of Refractory Metals & Hard Materials, 2006
)