EFFECT OF HARD METAL PRODUCTION ON THE ENVIRONMENT

This paper deals with production of hard metal by powder metallurgy and its effect on the environment. Hard metal is a composite material that consists of tungsten carbide as the hard refractory phase and cobalt or nickel as the soft metal binder phase. It cannot be produced by classical casting technology. Owing to its excellent properties, such as high hardness, wear and heat resistance etc., hard metal can be applied in a variety of industrial fields. Powder metallurgy is a technology for production of a wide range of materials as net-shape products from a compacted and sintered powders mixture. In this paper the impact of all stages of hard metal production by powder metallurgy on the environment is analysed. The presented analysis shows that production of hard metal by powder metallurgy has a minimum effect on the environment

Effect of boron and tungsten carbides on the properties of TiC-reinforced tool steel matrix composite produced by powder metallurgy

The influence of boron carbide and tungsten carbide on the apparent porosity, density, coercive force, hardness and microstructure of metal matrix composite of the Ferro-TiC type, is presented in this paper. The samples of investigated steel/titanium carbide composite were produced by powder metallurgy process, i.e. by powders mixing and compacting followed by sintering in the vacuum furnace. According to the results, steel/titanium carbide composite materials with addition up to 11.9 vol.% of boron carbide are interesting to detailed investigation as well as materials having more than 17.2 vol.% of tungsten carbide because these compositions show significant changes in hardness and coercive force values

The influence of the processing parameters on the porosity and microhardness of sintered Ti-20Nb biomedical alloy

Titanium based alloys are increasingly used in biomedicine due to their favourable properties. However, because of their high cost, new methods are being developed to produce more economical alloys. Therefore, in the framework of this work, Ti-20Nb alloy was produced by powder metallurgy. Namely, experimental alloy was prepared by mechanical alloying in a ball mill. The samples were singled out from the powder mixture and pressed on a hydraulic press. Sintering was carried out in a tube furnace in an argon atmosphere. Different processing parameters regarding the time and temperature of sintering were applied. Chemical homogeneity was analysed using the energy-dispersive spectrometry. Porosity was observed using the light microscope and microhardness was determined by Vickers method. The obtained results show that with a small correction of the applied technological parameters, in terms of time extension of mixing/mechanical alloying, it is possible to produce economically Ti-20Nb alloy having the properties suitable for biomedical application by using powder metallurgy technology