Effect of Orientation on Friction Characteristics of Single-Crystal Beryllium in Vacuum (10(exp -10) Torr)
Abstract
Studies were conducted to determine the influences of the crystallographic orientation of single-crystal beryllium on its friction characteristics when in sliding contact with sapphire and polycrystalline beryllium and aluminum oxide. Experiments were conducted in a vacuum of 10(exp -10) torr with a 3/16-inch hemispherical-radius beryllium crystal sliding on a flat of beryllium and aluminum oxide. The rider was loaded against the flat with various loads from 100 to 1500 grams and the flat disk was rotated to give a sliding speed of 0.013 centimeter per second. The results of the investigation showed that the basal plane exhibited lower friction than the prismatic slip plane. With the basal plane parallel to the interface, lower friction coefficients were observed in the <1120> than in the <1010> directions. The lowest friction coefficient for basal orientation was obtained with the basal plane inclined 135 deg to the sliding interface. The friction coefficient of single-crystal beryllium sliding on sapphire was lower than that of single-crystal beryllium sliding on polycrystalline aluminum oxide. With sapphire, brittle fracture of sapphire was observed, while with polycrystalline aluminum oxide, shear of beryllium was observed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1966
- Accession Number
- ADA400040
Entities
People
- Donald H. Buckley
Organizations
- National Aeronautics and Space Administration