David Arenz

US Patent:

48637980, Sep 5, 1989

Filed:

Jul 21, 1988

Appl. No.:

7/222257

Inventors:

David L. Arenz - Whittier CA
Edward L. Paquette - Claremont CA
Marc G. Simpson - Los Angeles CA

Assignee:

Refractory Composites, Inc. - Whittier CA

International Classification:

B32B 900

US Classification:

428368

Abstract:

A porous substrate is formed from discrete elements preferably anisotropic and permeable to oxygen and preferably having a first coefficient of thermal expansion. A pyrolytic material permeable to oxygen may be deposited in a thin layer on the discrete elements. A barrier material (e. g. boron carbide or silicon carbide) may be deposited in a thin layer on the pyrolytic material to inhibit diffusion of elements into the pyrolytic material. A material impermeable to oxygen (e. g. boron nitride or silicon nitride) may be deposited in a thin layer on the barrier material. A refractory matrix permeable to oxygen may be deposited on the impermeable material. The matrix may include a metallic element (e. g. silicon, hafnium, tantalum or zirconium) and another element (e. g. oxygen, nitrogen, carbon or boron) chemically bonded to the metallic element.