Production and properties of sintered composites high speed steel-tungsten carbide-copper phosphorus
Jan Leżański, Marcin Madej, Dorota Smoleń Akademia Górniczo-Hutnicza, Wydział Metalurgii i Inżynierii Materiałowej, al. Mickiewicza 30, 30-059 Kraków
Annals 2 No. 5, 2002 pages 283-286
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abstract Attempts have been made to describe the chemical composition and the production process parameter strength and wear resistance composites. The experimental results was partially presented in another publications. In this paper have been studied production and properties of composite high speed steel-tungsten carbide-copper phosphorus. The high speed steel powder was mixed with tungsten carbide WC, copper phosphorus and electrolytic copper. The compositions of the powder mixes were cold compacted uniaxially at 800 MPa. Green compacts were sintered in vacuum at temperatures 1050, 1150 and 1200°C. Dilatometric curves for the sintering are shown in Figure 1. Figure 2 shows the variation in green density for each powder mixes. Attempts include the as sintered density (Fig. 3), densification during sintering (Fig. 4), Brinell hardness (Fig. 5), benching stress (Fig. 6). Microstructural analysis of the as sintered structures required to use a number of techniques, including optical microscopy (Fig. 7), X-ray diffraction (Fig. 8) and EDX analysis (Fig. 9). From the analysis of the obtained results and microstructural observations it may be concluded that the as sintered properties of composites is affected by the composition of powder mixes, depend on contents of tungsten carbide, copper and phosphorus. The present study shown that we can produce fully dense high speed steel based composites. Oversintering leeds to a grain growth which, in consequence, decreases the mechanical strength of the composite materials.