Effect of the microstructure of heterogeneous mixture on regularities of gas-free combustion

We performed a series of experiments on investigation of the microstructure of the initial charge for gas-free combustion, including investigation of compressibility, electroconductivity, thermal conductivity, rate of charge burning, as well as metallographic investigations. The determining role of the shape of particles and their capacity of formation of a continuous skeleton, as well as their impact on regularities of gas-free combustion have been identified. It has been shown that the velocity and mode of propagation of the gas-free combustion front are determined by the transfer of heat between metal particles in the initial reaction mixture, with the limiting role being played by contacts between particles. The method of atomic tunnel microscopy was used to study the micro relief of the surface of particles and determine the most probable width of micro gaps between the particles at the point of their contact. The presence of these gaps leads to a strong dependence of the mixture heat conduction on the gaseous atmosphere (vacuum, helium and air).