摘要:
This disclosure enables direct 3D printing of preceramic polymers, which can be converted to fully dense ceramics. Some variations provide a preceramic resin formulation comprising a molecule with two or more C═X double bonds or C≡X triple bonds, wherein X is selected from C, S, N, or O, and wherein the molecule further comprises at least one non-carbon atom selected from Si, B, Al, Ti, Zn, P, Ge, S, N, or O; a photoinitiator; a free-radical inhibitor; and a 3D-printing resolution agent. The disclosed preceramic resin formulations can be 3D-printed using stereolithography into objects with complex shape. The polymeric objects may be directly converted to fully dense ceramics with properties that approach the theoretical maximum strength of the base materials. Low-cost structures are obtained that are lightweight, strong, and stiff, but stable in the presence of a high-temperature oxidizing environment.
摘要:
A method for fabricating a metal-ceramic composite article includes a) depositing at least one layer of a powdered material onto a target surface, where the powdered material includes at least one metal and an energy-beam responsive ceramic precursor, and b) densifying the at least one metal and chemically converting at least a portion of the energy-beam responsive ceramic precursor to a ceramic material to form a densified layer by directing an energy-beam onto the at least one layer.
摘要:
A method for producing solidified fiber bundles includes applying a melt or solution to a carrier web forming a viscous coating, applying parallel filaments under tension to the carrier web, and pressing the filaments into the viscous coating, forming an impregnate. The coating is partially solidified until a plastically deformable state of the impregnate is obtained by vaporizing the solvent, thermal curing and/or cooling. The impregnate is rolled onto a winding core to form a roll while maintaining a winding tension of the filaments in the impregnate. The outer roll is fixed on the winding core by a sleeve and/or by adhesive tape. The impregnate is solidified by vaporizing the solvent, thermal curing and/or cooling. The solidified impregnate is divided up to form solidified fiber bundles. A pressure produced by the winding tension of the filaments in the impregnate is exerted on the roll.
摘要:
A composite article includes a substrate and a protective layer on the substrate. The protective layer includes a non-oxide ceramic matrix and a refractory phase within the non-oxide ceramic matrix.
摘要:
Embodiments of the present invention disclosed herein include a sintering aid composition that has a material useful for sintering, an amine, and optionally a carboxylic acid.
摘要:
Embodiments of the present invention disclosed herein include a sintering aid composition that has a material useful for sintering, an amine, and optionally a carboxylic acid.
摘要:
A composite article includes a substrate and a protective layer on the substrate. The protective layer includes a non-oxide ceramic matrix and a refractory phase within the non-oxide ceramic matrix.
摘要:
The invention relates to a method for continuously producing pre-ceramic polymers. The inventive method consists in synthesising polymers, in separating polymers from a reaction mixture and in thermally conditioning for defining a cross linkage degree and Theological properties, wherein all said steps are integrated into a single method. The thus obtainable polymers are used in the form of an initial material for producing non-oxidised ceramics in ternary X/Y/N or X/Y/N/C quaternary systems. Said materials are characterized by the high mechanical, thermal and chemical resistance thereof, wherein any X and Y combination can represent in particular Si, B, P, Al, Ti, V, Zr, Ta elements.
摘要翻译:本发明涉及连续生产预陶瓷聚合物的方法。 本发明的方法包括在将聚合物与反应混合物分离并在用于定义交联度和热学性质的热调节中合成聚合物,其中所有所述步骤被整合成单一方法。 由此获得的聚合物以用于在三元X / Y / N或X / Y / N / C四元体系中生产非氧化陶瓷的初始材料的形式使用。 所述材料的特征在于其机械,耐热和耐化学性能高,其中任何X和Y组合可特别表示Si,B,P,Al,Ti,V,Zr,Ta元素。
摘要:
Direct thermal syntheses in the absence of catalyst, of poly(borazylenes) and of oligomers of borazine with polyhedral boranes, carboranes or heteroboranes are disclosed. The products of these syntheses are precursors to BN or other boron-containing ceramics.
摘要:
Boron-containing ceramics are formed from organoboron preceramic polymers which are carboralated acetylenic polymers. The polymers can be formed by carboralating acetylenic or diacetylenic diols and condensing the diols to form carboralated polyesters. In an alternative process, polydiacetylene formed by the polymerization of diacetylene monomers having conjugated triple bonds are carboralated subsequent to polymerization. A process for obtaining readily soluble polydiacetylenes comprises heating a diacetylene diol in a high boiling solvent.