Functional and structural particularities diffusion barriers in high- temperature coatings for heat-resistant composite materials.

摘要

Basic principles are formulated for working out the coatings for protection of carbon materials (CM) from high temperature oxidation, on the strength of which the analysis is carried out to choose the compounds most effective for forming of each structural layer as well as the coating as a whole. Calculations were performed for thermodynamical equilibrium in Me-Si-C, Me-C-B-Si and Me-C-Si-O systems (where Me is Ti, Zr or Hf) along with analysis of physical and chemical properties of various compounds, that showed that the most perspective systems for producing of heatproof composition coatings on CM are types of Me-C-B-Si (where Me are transition metals of IV-a - Vl-a groups). Certain laws of high temperature oxidation (1400 ° C) of composition coatings of the C-Ti-Mo-B-Si system on graphite were explored. Experiments were carried out to illustrate the Influence of various barrier diffusion layers on protective properties of the coatings.