Boron carbide cermet structural materials with high flexure strength at elevated temperatures
AssigneeThe Dow Chemical Company
InventorsAleksander J. Pyzik, Sharon M. Fuller, Donald R. Beaman
Life of this patent
Estimating the term…
Abstract
Prepare boron carbide-aluminum structural composites by infiltrating molten aluminum or aluminum alloy into a porous preform that is either unbaked or baked at a temperature of up to 1800.degree. C. to form a densified cermet and then heat treat the cermet in air or an oxygen-containing atmosphere to form a dense outer surface layer of aluminum oxide. The resulting structural cermets can withstand prolonged exposure to temperatures above the melting point of aluminum without suffering undue degradation of physical properties such as flexure strength.
Claims7
A boron carbide-aluminum structural composite having a dense surface layer of aluminum oxide about 5 to 13 microns in thickness that is substantially free of carbon, and a microstructure that comprises isolated boron carbide grains or clusters of boron carbide grains surrounded by a multiphase matrix that comprises aluminum borides, aluminum borocarbides and free metal, the metal being aluminum or an aluminum alloy.
Dependencies are inferred from the claim text.