The mechanism of phase and structure formation of the Ti-B-Fe system in a combustion wave

The mechanism of phase changes in the Ti-B-Fe system in a combustion wave f or a mixture of Ti, B, and Fe powders and a ferroboron alloy-titanium mixtu re with the same proportion of elements is studied. It is found that the me chanism of structure formation depends significantly on the type of contact between the initial components, An x-ray phase and x-ray spectrum and stru ctural microanalyses of the quenched layers of specimens show that the firs t contact melts occurring in the combustion wave are ferroboron (the first type of mixture) or ferrotitanium (the second type) melts, In the first cas e, the calculated high-melting compound TiB2 forms as a result of the inter action between the two melts; in the second case, it forms as a result of t he interaction of the melt with solid ferroboron, which, in turn, determine s the different type of microstructure of the final combustion products. Th e highly disperse and more homogeneous structure of the products forms afte r combustion of the second-type mixture. A method of producing the Ti-B-Fe pore-free composite produced during the self-propagating high-temperature s ynthesis (SHS-composite) by combining the combustion with rolling of the sy nthesis products is considered. In properties, the resulting material is si milar to tungsten-carbide materials.