Accession Number : AD0703555

Title :   THE ABLATION OF HEAT-RESISTANT POLYMERS (1. ANALYSIS OF THE MECHANISM OF ABLATION DESTRUCTION),

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Maciulis,A. N. ; Zilinskaite,L. P.

Report Date : 10 FEB 1970

Pagination or Media Count : 15

Abstract : Investigation of kinetics of ablation destruction of epoxy compounds with fillings of copper powder and zinc dust is presented. Tests were carried out in a deoxidizing gas stream environment by means of thermodynamic and aerodynamic characteristics. Maximum ablation intensity for epoxy compounds with fillings of copper powder appears not at maximum stream enthalpy value but at its mean value. This may be explained by the occurrence of several simultaneous physical and chemical processes some of which increase and others decrease ablation intensity. The article deals with the case when the stream enthalpy is large and the influence of processes tending to decrease ablation intensity is greater than that which is produced by the processes taking place at mean stream enthalpy values. Experiments for ablation intensity dependence depending on Re number of the stream were made. This dependence for epoxy compounds with fillings of zinc dust appears only during the first few seconds on commencement of test, but as the test proceeds the intensity dependence curve tends to become linear. It is quite different for epoxy compounds filled with copper powder. In this case nonlinear ablation intensity dependence upon Re number predominates. Ablation intensity dependence on stream enthalpy and Re number characterizes the properties of the material, from which we may draw conclusions about the spontaneous reinforcement of the material during ablation. (Author)

Descriptors :   (*HEAT RESISTANT PLASTICS, *ABLATION), EPOXY RESINS, ADDITIVES, COPPER, ZINC, HEAT SHIELDS, THERMOCHEMISTRY, USSR

Subject Categories : Physical Chemistry
      Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE