摘要:
A chemically doped boron coating is applied by chemical vapor deposition to a silicon carbide fiber and the coated fiber then is exposed to magnesium vapor to convert the doped boron to doped magnesium diboride and a resultant superconductor.
摘要:
Silicon carbide filament is produced by overcoating a carbon monofilament core using continuous process vapor deposition. The deposition takes place by passing the carbon monofilament through a reactor into which gaseous sources of silicon and carbon are injected. At a deposition temperature of about 2370.degree. F., a deposit of fine grained beta crystals of silicon carbide are formed. Application of a thin protective coating of boron-based refractory material on the surface of the silicon carbide filament both adds strength and provides a surface which is readily bonded to both metals and epoxy matrix materials during the casting of composite structures.
摘要:
Improved articles of manufacture are disclosed, together with methods for preparing such articles, whereby the surface of a graphite or comparable substrate is first densified with carbon to reduce surface porosity while still retaining sufficient surface texture to enhance the adherence of a subsequently applied boron coating.
摘要:
Improved articles of manufacture are disclosed, together with methods for preparing such articles, whereby the surface of a graphite or comparable substrate is first densified with carbon to reduce surface porosity while still retaining sufficient surface texture to enhance the adherence of a subsequently applied boron coating.
摘要:
Improved articles of manufacture are disclosed, together with methods for preparing such articles, whereby the surface of a graphite or comparable substrate is first densified with carbon to reduce surface porosity while still retaining sufficient surface texture to enhance the adherence of a subsequently applied boron coating.
摘要:
A porous preform is densified by heating while emersed in a precursor liquid. Heating is achieved by passing a current through the preform or by an induction coil immersed in the liquid. Ways to control the densification process are also described.
摘要:
This invention is directed to a surface treatment for SiC monofilament developed for the purpose of increasing the transverse strain-to-failure of composites, particularly aluminum composites. The surface treatment includes a fine grain SiC region adjacent to the bulk or stoichiometric SiC region and a transition region which interacts with the matrix material.
摘要:
In accordance with the invention there is provided a method of producing a densified carbon preform having interior a porous region of graded carbon-silicon carbide, carbon-silicon nitride or ceramic-ceramic composition.
摘要:
A porous preform is densified by heating while emersed in a precursor liquid. Heating is achieved by passing a current through the preform or by an induction coil immersed in the liquid. Ways to control the densification process are also described.
摘要:
The invention relates to a surface treatment for stoichiometric silicon carbide. A carbon-rich silicon carbide layer is applied over the silicon carbide. In the case of the silicon carbide surface, the ratio of silicon to carbon in the carbon-rich layer varies from one at the silicon carbide interface to near zero in the interior of the carbon-rich layer to greater than zero and preferably 0.3 to 0.5 on the surface of the carbon-rich layer remote from the interface. A preferred method of making the silicon carbide layer is also presented.