Investigation of SHS process in W-TI-C system for production of tungsten carbides WC and W 2C. Application of carbides mixture for cast iron modification

Powders of tungsten and titanium carbides have been produced from the mixture of tungsten, titanium and soot by the method of self-propagating high-temperature synthesis (SHS) with the use of mechanochemical treatment (MT). To synthesize tungsten carbides, there has been used SHS of titanium carbide in the mixture “tungsten-titanium-soot”, which has further initiated the synthesis of tungsten carbide (carbides). Optimal conditions for the production of composition with maximum tungsten content have been found. Powders (mixture of tungsten and titanium carbides) with minimum particle size of about 30 nm have been produced. It has been revealed that the output tungsten carbides WC and W2C considerably depends on the composition of mixture “tungsten-titanium-soot” and time of its MT. Modifiers, which have been investigated for the processes of intra-mold cast iron modification, were produced with the use of MT based on SHS products and powders of metals. The usage of modifiers of the composition 35-40 % WC ÷ 10-15 % TiC ÷ 50 % Zr has allowed to increase Brunell hardness by 13,1 %, tensile strength - by 19,8 %, relative wear resistance - by 69 %, corrosion resistance in hydrochloric acid - by 28 % of cast iron samples at the content of modifier active particles being 0,038 %.