WC powder was obtained from recycling cemented carbide scraps. This metal power contained tungsten carbide (WC) at 89.17% titanium (Ti) at 4.90% tantalum (Ta) at 3.56% niobium (Nb) at 1.31% and molybdenum (Mo) at 0.93%. Its particle size and distribution was in the range of 0.03-85.31 µm. After quality improvement of the metal powder by ball milling screening and separating the compounds the result showed that the particle size of the metal powder was decreased to 0.01-0.10 µm (10-100 nm). The average size of the powdered particle was 28 nm. The tungsten powder was in more perfect condition by 95.85%

This research was on the production of hardmetal from recovery of tungsten carbide tool scraps recycling through ball milling for 40 hours. The metal powder obtained which was of the size between 0.11-0.22 µm was composed of 96.69% of tungsten carbide (WC) 1.68% of tantalum (Ta) 1.21% of titanium (Ti) and 0.42% of niobium (Nb). When mixed with 5-15% cobalt binder metal cold isostatic press (CIP) sintered at 1450 ° C it became hardmetal work piece dimension 12.39 x 13.82 x 5.60 mm with 1410 HV hardness and 14.34 g/cm3 density. The result of S45C steel turning was tools life good. The research concluded that the hardmetal work piece produced by the developed material had suitable basic specification and would lead to the development in working in the future.

This research is to study the approach for producing the hard materials part by using tungsten carbide powder. The tungsten carbide powder derived from Tungsten scraps recycle processes which are Insert tools scraps the waste of metal removal process or derived from usage of machining on machine tools which are the production of metal powder by recovering cemented carbide to tungsten carbide powder and bring it to recycle. The first experiment of this research starts with the production of pure tungsten carbide powder in order to produce the hard metal part how to possibly produce the durable part or hard materials. Preparing tungsten carbide powder which pulverized and mixed with Cobalt co-binder less than 17% so that molding with the pressure 300 Mpa and sintering at 1430 degree Celsius to the cemented carbide part in Insert tools type rectangle SNMG standard 120408 for turning. The result is found that the Insert tools have hardness about 1385 HV and density 13.45 g/cm3 and then they are tested to machine specimens in AISI 1045 type. The developed Insert tools can be machining metal removal them as well as the imported Insert tools. It is concluded that the production of Insert tools by recycling of tungsten carbide is qualified as the imported Insert tools. In addition it is the new developed research in Thailand to be the approach for domestic cutting tools product instead of the imported cutting tools.

The recycling of materials is the recovered process and the important approach for sustainable development. This research is to study recycling tungsten carbides from cemented carbide scraps by extracting the dissolved of binder phase and to study the un-dissolved substrate which stayed condition and size in WC particles. The experiment of this research starts in laboratory with electrolysis is found that the appropriate operating potential is 0.20-1.40 volts at 30-80 oc treated in 1N-7N HCl concentrations aqueous solution as well as the movement of solution and specimens had an effect on capacity of dissolution. Additionally these factors are affected to purity and passivation of WC particles. According to the above experiment it leads to design and create the semi-automatic cemented dissolution machine with electrolysis. This machine can contain the scraps up to 2.5 kilograms in rev 0-25 rpm (revolutions per minute) at electric current 0-50 ampere in electric voltage 0-15 volts. Its flowing process can be 15 lpm (litre per minute) and minute) and temperature is up to 90 oc. Furthermore there are the relative WC power invention processes included residues washing leaching ball milling drying screening and quality examination. The result of developed machine is capacity of tungsten carbide production is in the range 16-50 gram/hour the obtained powder is 97.49% of tungsten carbide (WC powder) which contained a few amount of cobalt. However the dissolution of cemented carbides with this machine can be selected the optimized factors to produce tungsten carbide (WC) to purify more than 99% ball milled them in the most suitable size and particle sized distribution between 0.30-20.00 μm. Afterwards combining cobalt 15% (WC-15%Co) and producing to cemented carbides insert tools rectangle as SNMG standard 120408 it appears that insert tools has a hardness not less than 1430 HV density not less than 14.10 g/cm³. In the other hands the production of tungsten carbides with advanced technology of dissolution machine and manufacturing machine to produce purely tungsten carbides powder has been required an investment charge of new research and development more than 9481888 baht.

This study developed the cemented tungsten carbide by steadily sintering at 1430 °C for one hour. The tungsten carbide structure is a long shape. Its grain size has a difference between width and length and there are high distribution of sizes and shapes. In comparison with the work piece which has the similar size of grain structure the milling duration of tungsten carbide is less even though the condition of WC-Co is the same (95% WC – 5% Co). When the sintering of 1400 °C with the identical milling duration is performed. It turned out that both grain structures of the tungsten carbide and the work piece are similar and their grain sizes are slightly different. However when the grain structures are almost the same and sphericity is increased the hardness and wear resistance will also be improved. Therefore the size of grain structure between 1.00 – 3.00 μm with the milling duration of 100 hours will provide a work piece that has a wear resistance according to international standard