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The regularities of the decomposition of malachite and its interaction with polystyrene (PS) and (PE) over a temperature range of 20 to 600°C were studied using the thermal analysis method. It was demonstrated that malachite is reduced by PS and PE, a process that occurs in two stages: the decomposition of malachite to copper oxide and its reduction to metallic copper. The values of the effective activation energy and preexponential factor for the reactions under study were determined.

The interaction of nickel(II) oxide with carbon, polyethylene, and polystyrene in the temperature range 20–1000°C has been investigated by thermal analysis. The interaction of NiO with carbon and polyethylene under these conditions results in complete nickel reduction. In the case of polystyrene, because of its low decomposition temperature, the reduction process is incomplete. As compared to reduction with polyethylene, reduction with carbon takes place at a much higher temperature (750 versus 370°C) and requires a higher activation energy (68 ± 3 versus 41 ± 1 kcal/mol).

An electrothermographic method was used to study the regularities of heat release and formation of the microstructure of tungsten disilicide with wide variation in the temperature regime of sample heating, including conditions modeling combustion-wave propagation in mixtures of tungsten and silicon powders. Emphasis is on the heat-release stage due to the crystallization of the disilicide phase from a supersaturated melt of WSi2-Si. At this stage of the process, self-acceleration of the heat release is observed even when the sample temperature decreases. Growth of tungsten disilicide crystals occurs only at the heat-release stage. When the system is kept at the maximum temperature of the thermogram, further crystal growth is not observed over a period of time exceeding the duration of heat release by a factor of 10–20.

The phenomenon of chemical activation is investigated using combustion of the Nb−C system in the presence of an activating additive, namely, polytetrafluoroethylene, as an example. Regions of the parameters of the process are found where the interaction occurs by two different mechanisms. The characteristic features of the process are established and the role of the activating additive in each region is determined.

Results of investigations of the kinetic laws and the mechanism of carbonizing Ti, Zr, Nb, Ta, Mo, and W over a wide temperature range and for different schemes of metal-carbon interaction (Me+carbon-containing gas, Me+graphite) are given. Much attention has also been given to establishing the interrelation between the microstructure of carbide phases and the kinetics and mechanism of their formation.

The phase formation processes in Ti−Si and Mo−Si systems were studied, using special markers simulating the behavior of large metal particles after they have passed the combustion front. It is shown that, depending on the combustion temperatures of the mixtures, phases can be formed by joint crystallization from the eutectic melt, or disilicides crystallize first and intermediate phases (Mo5Si3 and TiSi) form by a solid-phase mechanism.

Combustion processes are considered for stoichiometric mixtures of niobium with carbon with substitution of some of the carbon black by an activating addition, i.e. fluoroplastic. It is shown that in the presence of a small amouni (0.1–1.0 wt.%) of fluoroplastic the mixture acquires the capacity to burn without using any additional procedures.

A solution of the nonstationary Stefan problem is presented for bodies of plane, cylindrical, and spherical symmetry in application to processes of diffusion interaction between metals and a gaseous oxidative medium.

The propagation of a combustion wave in a porous metal specimen burning in a gaseous reagent is largely dependent on the dispersion of the metal particles, the porosity, the gas pressure, and the previous heat treatment. Infiltration combustion of titanium, zirconium and hafnium may burn layerwise or in a surface mode depending on these conditions, and the mode of burning has a decisive effect on the composition of the final product. Samples of titanium powder burned layerwise in hydrogen, regardless of the porosity, pressure or particle size. The same applied to specimens previously heat-treated or dehydrogenated. Hafnium and zirconium powders burn in the surface mode, while dehydrogenated ones burn in layer mode. Measurements show the dehydrogenated zirconium and hafnium to have a permeability 1.5 times as great as that of the initial material, with a commensurate increase in the combustion rate.