OXIDATION-INHIBITED CARBONOUS MATERIALS

Abstract

Composites comprising high-temperature fibers reinforcing a carbonous matrix are protected from oxidation by a B2O3-based glass which includes a refractory oxide to stabilize the viscosity of the glass. Precursors of B2O3 and the refractory oxide are dispersed into a carbon char-yielding material; the material is used to impregnate sheets of fibers; the sheets are laid up as plies; and the laid-up plies are carbonized and graphitized using heat and pressure to form a composite structure. The composite structure is then coated with an additional mix of char-yielding material and precursors, and the coated structure is heated to carbonize the material and leave a seal coat on the structure. Then, an outer coating of a refractory material is deposited on the structure. Oxygen which seeps through the seal coat is initially scavenged at high temperatures by the RO and B2O3 precursors, converting the same to a B2O3-RO glass which protects both the internal pore surfaces of the composite as well as the outer structural surfaces from oxidation.

Source: Google Patents

35 USC §181 Secrecy Order

Inventor

• 1PAUL E. GRAY

Sensitive facility: San Diego CA (SAIC/General Dynamics)