• Transactions of Materials Processing
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• v.19 no.3
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• pp.191-196
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• 2010

Tungsten-carbide as typical difficult-to-cut material has excellent mechanical properties such as high thermal resistivity, mechanical strength and chemical durability. However, it is next to impossible for tungsten-carbide to be fabricated the needed parts by cutting process. In this study, for establishing the micro fabrication method of tungsten-carbide for micro injection or compression molding core, the investigation on micro cutting characteristics of tungsten-carbide green part which is made by powder injection molding process and easy to cut relatively was performed. For this, micro endmilling experiments of tungsten-carbide green part were performed according to various cutting conditions. Finally, the wear trend of micro endmill and the appearance of micro rib according to feed-rate and cutting depth per step were analyzed through SEM images of micro cutting feature and microscope images of micro tools.

• Journal of the Korean Society for Heat Treatment
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• v.36 no.4
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• pp.206-214
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• 2023

Tungsten carbide has many industrial applications due to its high electrical and thermal conductivity, high melting temperature, high hardness and good chemical stability. Because tungsten carbide is difficult to sinter, it is sintered with nickel or cobalt as a binder and is currently used in nozzles, cutting tools, and molds. Alumina is reported to be a viable binder for tungsten carbide due to its higher oxidation resistance and lower cost than nickel and cobalt. The ultrafine tungsten carbide-graphene-alumina composites were rapidly sintered in a high frequency induction heating active sintering unit. The microstructure and mechanical properties (fracture toughness and hardness) of the composites were investigated and analyzed by Vickers hardness tester and electron microscope. Since the high-frequency induction heating sintering method enables high-speed sintering, ultrafine composites can be prepared by preventing grain growth. In the tungsten carbide-graphene-alumina composites, the grain size of tungsten carbide increased with the amount of alumina participation. The hardness and fracture toughness of the tungsten carbide-5% graphene- x% alumina (x = 0, 5, 10,15) composites were 5.1, 8.6, 8.6, and 8.4 MPa-m^1/2 and 2384, 2168, 2165, and 2102 kg/mm², respectively. The fracture toughness increased without a significant decrease in hardness. Sinterability was improved by adding alumina to tungsten carbide-graphene.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.581-584
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• 2003

The austenitic STS 304 stainless steel was turned to clarify the effects of tool geometry on the tool wear. The wear of TiN-TiCN-TiC-TiAlN coated tungsten carbide tool was the smallest, exhibiting larger wear in the order of Si-Al-O-N ceramic, TiN coated tungsten carbide, TiN-TiCN-TiN coated tungsten carbide, TiC-TiN cermet and M20 tungsten carbide tools at the same cutting conditions. The S-type tool of M20 with large approach angle showed the longest tool life of all tools used in this tests due to preventing the groove wear of the side cutting edge. The wear of the S-type tool with the rake angle of 15$^{\circ}$became smaller than with that of -5$^{\circ}$, but the tool with the nose radius of 0.8mm did not perform much better with increasing the rake angle.

• Korean Journal of Materials Research
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• v.18 no.12
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• pp.635-639
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• 2008

In this paper, experimental studies of the regrinding of tungsten carbide (WC-Co) tools for high-speed machining were conducted. Regrinding and a subsequent evaluation test were carried out for a flat endmill tool with diameters of 10 mm and 3 mm using a CNC five-axis tool grinder and a CNC three-axis machining center. Tool wear on the two types of endmill tools increased as the cutting length increased, and the tool wear was not influenced by the regrinding state. In case of the micro endmill with a tool diameter of 3 mm, the effective regrinding time was determined for a flank wear threshold of 0.3 mm considering the tool life according to cutting length. The tool lives of the 10 mm and 3 mm endmill tools were increased by 80% and 72%, respectively. This conclusion proves the Feasibility of the recycling of tungsten carbide materials in the high-speed machining of high-hardened materials for industrial applications.

• Journal of the Korean institute of surface engineering
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• v.31 no.6
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• pp.400-406
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• 1998

Tool life characteristics were investigated for the TiN coated (PVD) tungsten carbide cutting tools to improve the tool life Experimental variables for Tin coating were coating time and cathode bias voltage and cuting variables were cutting speed and feel rate. As a experiment result, TiN coated tool was extended about from 2.14 to 2.7 times than that of not coated tungsten carbide tools. Also, coating thinkness is much affected to tool life.

• Journal of the Korean institute of surface engineering
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• v.15 no.3
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• pp.138-145
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• 1982

The effects of the simultaneous variations of the ratio of feed gases(H2/N2 Flow ratio), feed gas flow rate (H2/N2, total-flow rate) and partial pressures of TiCl4 (PTiCl41) as well as deposition time and cobalt content of the substrate on the deposition rate of the TiN Coated Cemented Tungsten Carbide Tools were investigated. Deposition was carried out in the temperature range of 930$^{\circ}C$-1080$^{\circ}C$ and an activation energy of 46.5 Kcal/mole can be calculated. Transverse rupture strength was noticeably reduced by the TiN coating on the virgin surfa-ce of Cemented Tungsten Carbide, the extent of which was decreased according to the coa-ting thickness. Microhardness value observed on the work was in the range of 1700∼2000kg/mm, which were in well agreement with the value of bult TiN. The wear resistance of TiN layers was performed by turning test and it was observed that crater and flank resistance remarkably enhanced by TiN coating.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.56-64
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• 2003

The effect of tool geometry on the tool wear in turning the austenitic stainless steel, STS 304 was investigated. The wear of TiN-TiCN-TiC-TiAlN coated tungsten carbide tool was the smallest, showing larger wear in the order of Si-Al-O-N ceramic, TiN coated tungsten carbide, TiN- TiCN- TiN coated tungsten carbide, TiC-TiN cermet and M20 tungsten carbide tools at the same cutting conditions. The S-type tool of M20 with the larger side cutting edge angle showed the smallest tool wear in all tests due to preventing the groove wear of the side cutting edge. The wear of the S-type tool with the rake angle of $15^{\circ}$ became smaller than with that of $-5^{\circ}$, but the tool with the nose radius of 0.8mm did not perform much better with increasing the rake angle.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.315-318
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• 2004

The Advantages of hot machining are the reduction of cutting forces, tool wear, and the increase of material removal rates. In this study, a hot-machining characteristics of milling by CBN tip was exprimentely analyzed, and the influence of the surface temperature and the depth of cut on the tool life were investigated. The selection of a heating method for obtaining ideal temperature of metals in machining is important. Faulty heating methods could induce unwanted structural changes in the workpiece and increase the cost. This study uses gas flame heating. It is obtained that tungsten carbide-alloyed has a recrystallisation temperature range of $800-1000^{\circ}C$ which is the high heating temperature that might induce unwanted structural changes. If it is performed at temperatures higher than $800^{\circ}C$ in machining, the possibility of unwanted structural changes and the increased wear of tool can be shown. Consequently, in hot machining of tungsten carbide-alloy, this study has chosen $400^{\circ}C-600^{\circ}C$ because the heating temperature might be appropriate in view of the cost and workpiece considerations. The results of this study experimentally shows a new machining method for tungsten carbide-alloyed that decreases the wear rate of machining tools

• Resources Recycling
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• v.21 no.1
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• pp.82-92
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• 2012

There are several kinds of tungsten carbide(WC) such as light bulbs, metal cutting tools, drill bits, mining tools, military ordinance, high speed tool steels, chemicals/catalysts, wear resistance parts, jet engine turbine blades, etc.. These days it has been widely studied for the recycling technologies of the used tungsten carbide(WC) from view points of economy and efficiency. In this paper, open/registered patents of US, JP, EP, and KR and SCI Journal related to recycling technologies of the used Tungsten Carbide(WC) between 1969-2011 were reviewed. Patents and papers were collected using key-words searching and filtered by filtering criteria. The trends of the patents and papers was analyzed by the years, countries, companies, and technologies.

• Journal of Powder Materials
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• v.29 no.1
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• pp.47-55
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• 2022

Tungsten carbide is widely used in carbide tools. However, its production process generates a significant number of end-of-life products and by-products. Therefore, it is necessary to develop efficient recycling methods and investigate the remanufacturing of tungsten carbide using recycled materials. Herein, we have recovered 99.9% of the tungsten in cemented carbide hard scrap as tungsten oxide via an alkali leaching process. Subsequently, using the recovered tungsten oxide as a starting material, tungsten carbide has been produced by employing a self-propagating high-temperature synthesis (SHS) method. SHS is advantageous as it reduces the reaction time and is energy-efficient. Tungsten carbide with a carbon content of 6.18 wt % and a particle size of 116 nm has been successfully synthesized by optimizing the SHS process parameters, pulverization, and mixing. In this study, a series of processes for the high-efficiency recycling and quality improvement of tungsten-based materials have been developed.