HIGH VISCOSITY REFRACTORY FIBERS
Abstract
Viscosity determinations on mixtures of silica with dispersed Cu at 3 concentrations (0.1, 3, and 10%) were made by fiber and rod elongation techniques. Coarse dispersions of Cu lower the viscosity of silica but fine dispersions may raise it. With essentially convective heating, such as in an open gas flame (or nose-cone reentry), even coarse dispersions can show appreciable net viscosity increases due to radiative cooling mechanisms associated with the reflective and emissive properties of the Cu particles. Two other additives, molybdenum disilicide at 10% and Cr2O3 at 5 and 7%, raise the viscosity of silica 2-1/2 to 12-fold. The emissivities and reflective properties of these additives indicate that radiative cooling effects similar to those of Cu would further increase viscosity under convective heating conditions. Oxyacetylene ablation tests were run on bullet shaped samples of plain silica and mixtures of 3 and 10% Cu in silica. The 10% Cu sample showed appreciably more resistance to ablation than either of the other samples and the 3% sample appeared to be more resistant than the plain silica. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 31, 1961
- Accession Number
- AD0264273
Entities
People
- Stanley A. Dunn
- William P. Roth