CHEMICAL CLASSES OF THE SHS PROCESSES AND MATERIALS

The paper concerns chemical issues of self-propagating high temperature synthesis. Chemical classes of the SHS processes and products are considered. The results of research into SHS chemistry are discussed according to the classification suggested by the author: solid solutions of nonmetals in metals, binary compounds (carbides, borides, silicides, nitrides, hydrides, oxides, chalcogenides, etc.), chemical mechanism of formation in combustion mode, and intermediate products. Single - phase multicomponent SHS systems involving complex carbides, oxides, nitrides, carbonitrides, hydrocarbides, and hydronitrides are also treated. An extended class of the SHS products comprises complex heterogeneous mixtures of refractory inorganic compounds, as well as hard alloys. The reactions used for synthesizing SHS products of different classes are presented. The use of SHS for producing organic and polymer compounds was experimentally shown to be possible. Finally, the discussion of some issues related to the crystalline structure and particle size of SHS products is presented which is important for understanding the process itself, as well as for practical application of SHS compounds of different classes.