A debonding layer is formed on fibers such as silicon carbide fibers by fing a thin film of a metal such as nickel or iron on the silicon carbide fibers and then annealing at a temperature of about 350-550.degree. C. to form a debond layer of a metal silicide and carbon. These fibers having the debond coating can be added to composite forming materials and the mixture treated to form a consolidated composite. A one heating-step method to form a consolidated composite involves inserting the silicon carbide fibers with just the initial metal film coating into the composite forming materials and then heating the mixture to form the debond coating in situ on the fibers and to form the consolidated composite. Preferred heating techniques include high temperature annealing, hot-pressing, or hot isostatic pressing (HIP).
A method for depositing a transfer material onto a receiving substrate uses a source of laser energy, a receiving substrate, and a target substrate. The target substrate comprises a laser-transparent support having a laser-facing surface and a support surface. The target substrate also comprises a composite material having a back surface in contact with the support surface and a front surface. The composite material comprises a mixture of the transfer material to be deposited and a matrix material. The matrix material is a material that has the property that, when it is exposed to laser energy, it desorbs from the laser-transparent support. The source of laser energy is positioned in relation to the target substrate so that laser energy is directed through the laser-facing surface of the target substrate and through the laser-transparent support to strike the composite material at a defined target location. The receiving substrate is positioned in a spaced relation to the target substrate. The source of laser energy has sufficient energy to desorb the composite material at the defined target location, causing the composite material to desorb from the defined target location and be lifted from the support surface of the laser-transparent support. The composite material is deposited at a defined receiving location on the receiving substrate. The method is useful for creating a pattern of biomaterial on the receiving substrate.
A method for creating a microarray of biomaterial uses a source of laser energy, a receiving substrate, and a target substrate. The target substrate comprises a laser-transparent support having a laser-facing surface and a support surface. The target substrate also comprises a composite material having a back surface in contact with the support surface and a front surface. The composite material comprises a mixture of the biomaterial to be deposited and a matrix material. The matrix material is a material that has the property that, when it is exposed to laser energy, it desorbs from the laser-transparent support. The source of laser energy is positioned in relation to the target substrate so that laser energy is directed through the laser-facing surface of the target substrate and through the laser-transparent support to strike the composite material at a defined target location. The receiving substrate is positioned in a spaced relation to the target substrate. The source of laser energy has sufficient energy to desorb the composite material at the defined target location, causing the composite material to desorb from the defined target location and be lifted from the support surface of the laser-transparent support. The composite material is deposited at a defined receiving location on the receiving substrate. The steps are repeated at successive defined target locations and successive defined receiving locations such that the composite material is deposited in a microarray of deposited composite material. The method is useful for creating, for example, a gene recognition array,
An device for depositing a transfer material onto a receiving substrate includes a source of pulsed laser energy, a receiving substrate, and a target substrate. The target substrate comprises a laser transparent support having a back surface and a front surface. The front surface has a coating that comprises a mixture of the transfer material to be deposited and a matrix material. The matrix material is a material that has the property that, when it is exposed to pulsed laser energy, it is more volatile than the transfer material. The source of pulsed laser energy is be positioned in relation to the target substrate so that pulsed laser energy is directed through the back surface of the target substrate and through the laser-transparent support to strike the coating at a defined location with sufficient energy to volatilize the matrix material at the location, causing the coating to desorb from the location and be lifted from the surface of the support. The receiving substrate is positioned in a spaced relation to the target substrate so that the transfer material in the desorbed coating can be deposited at a defined location on the receiving substrate.
The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) in composite bodies. The oxidation protection mechanisms include getterer materials which are added to the composite body which gather or scavenge undesirable oxidants which may enter the composite body. The getterer materials may be placed into at least a portion of the composite body such that any undesirable oxidant approaching, for example, a fiber reinforcement, would be scavenged by (e.g., reacted with) the getterer. The getterer materials) may form at least one compound which acts as a passivation layer, and/or is able to move by bulk transport (e.g., by viscous flow as a glassy material) to a crack, and sealing the crack, thereby further enhancing the oxidation protection of the composite body. One or more ceramic filler materials which serve as reinforcements may have a plurality of super-imposed coatings thereon, at least one of which coatings may function as or contain an oxidation protection mechanism. Specifically, a coating comprising boron nitride which has been engineered or modified to contain some silicon exhibits improved corrosion resistance, specifically to oxygen and moisture. The coated materials may be useful as reinforcing materials in high performance composites to provide improved mechanical properties such as fracture toughness. The present invention also relates to improved composites which incorporate these materials, and to their methods of manufacture.