Boron carbide fiber reinforced articles
AssigneeAdvanced Ceramic Fibers, LLC
InventorsJohn E. Garnier, George W. Griffith
Life of this patent
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Abstract
Methods of producing continuous (or discontinuous) boron carbide fibers. The method comprises reacting a continuous or discontinuous carbon fiber material and a boron oxide gas within a temperature range of from approximately 1400° C. to approximately 2200° C. Articles including such partially or fully converted fibers may be provided, including such reinforcing fibers in a matrix of ceramic (a CMC), in metal (a MMC), or other matrix (e.g., polymer, etc.).
Claims22
An article comprising fibers dispersed in a matrix, the fibers having a diameter of less than or equal to approximately 20 μm and comprising a boron carbide conversion layer over an unconverted carbon fiber core, the boron carbide conversion layer comprising carbon from a starting carbon fiber material that has been converted to boron carbide;
- wherein an adherence strength of the boron carbide conversion layer is at least equal to an adherence strength of carbon to itself in the unconverted carbon fiber core.
An article comprising boron carbide fibers dispersed in a matrix, the boron carbide fibers having a diameter of less than or equal to approximately 20 μm and wherein the boron carbide fibers comprise:
- a boron carbide conversion layer over an unconverted carbon fiber core, such that the boron carbide fiber is a carbon fiber that has been partially converted to boron carbide wherein an adherence strength of the boron carbide conversion layer is at least equal to an adherence strength of unconverted carbon in the unconverted carbon fiber core to itself in such a partially converted fiber;
- wherein the boron carbide conversion layer comprises at least one of alpha, beta, tetragonal, orthorhombic, or rhombohedral polymorphs of boron carbide.
An article comprising boron carbide fibers dispersed in a matrix, the boron carbide fibers having a diameter of less than or equal to approximately 20 μm and wherein the boron carbide fibers comprise:
- a boron carbide conversion layer over an unconverted carbon fiber core, wherein the boron carbide conversion layer is boron rich, comprising B10.4C, such that the boron carbide fiber is a carbon fiber that has been partially converted to boron carbide wherein an adherence strength of the boron carbide conversion layer is at least equal to an adherence strength of unconverted carbon in the unconverted carbon fiber core to itself in such a partially converted fiber;
- or
- a boron carbide converted thickness that extends through the full diameter of the boron carbide fiber, such that the boron carbide fiber is a fiber that has been substantially fully converted to boron carbide having a stoichiometry of B10.4C.
Dependencies are inferred from the claim text.