Abstract: Systems and methods are provided for monitoring and/or controlling laser drilling processes based on atomic emission spectral emissions that are collected in real time during laser drilling. The systems and methods may be used to monitor and control laser drilling operations across a range of materials, e.g., metals (including alloys) and ceramics, and may be used to identify spectral characteristics that signify hole completion and to manage/discontinue laser drilling operations based thereon. The ability to precisely monitor for hole completion provides the important advantage of reducing unnecessary laser pulses, which otherwise could reduce manufacturing efficiency and/or increase thermal or mechanical damage to the component material. The systems and methods may also be employed to control laser drilling operations so as to enhance hole quality and/or to implement corrective action when/if necessary to ensure that laser drilling operations yield high quality drilled holes.

Abstract: Systems and methods are provided for monitoring and/or controlling laser drilling processes based on atomic emission spectral emissions that are collected in real time during laser drilling. The systems and methods may be used to monitor and control laser drilling operations across a range of materials, e.g., metals (including alloys) and ceramics, and may be used to identify spectral characteristics that signify hole completion and to manage/discontinue laser drilling operations based thereon. The ability to precisely monitor for hole completion provides the important advantage of reducing unnecessary laser pulses, which otherwise could reduce manufacturing efficiency and/or increase thermal or mechanical damage to the component material. The systems and methods may also be employed to control laser drilling operations so as to enhance hole quality and/or to implement corrective action when/if necessary to ensure that laser drilling operations yield high quality drilled holes.

Abstract: A process for the fabrication of a photonic crystal (and the crystal produced thereby) comprising producing a first beam of coherent light; generating a second and a third beam of coherent light each in a fixed phase relationship with the first beam; aligning the beams of coherent light so as to form a fixed relative angle of incidence between each pair of beams and to form an evanescent light interference pattern grid on a substrate having a first electrostatic charge; introducing into the evanescent light interference pattern grid a substance having a second electrostatic charge of an attractive nature to the first electrostatic charge; positioning the substance with the second electrostatic charge using the evanescent interference pattern grid in a planned manner on the substrate so as to form a photonic crystal.

Abstract: A photonic crystal fabrication apparatus (10) has a LASER (12) optically coupled to a multi-mirror assembly (16) for directing beams of coherent light towards each other beneath a base (40) of a sample cell (18). The sample cell has a removable top (44) in order to permit receipt of components for fabrication of photonic crystals. Formative beams of coherent light interfere to form a grid (20) for receiving primary crystal ingredients, and manipulating beams of coherent light (124) designate defects in the grid for receiving sacrificial spacer materials. The apparatus and method presented herein are capable of fabricating single photonic crystals having properties substantially unobtainable with the prior art.

Abstract: A process for making bone implants from calcium phosphate powders is disclosed. This process involves selectively fusing layers of calcium powders that have been coated or mixed with polymer binders. The calcium powder mixture may be foamed into layers and the polymer fused with a laser. Complex three-dimensional geometrical shapes can be automatically replicated or modified using this approach.

Abstract: A process for making bone implants from calcium phosphate powders is disclosed. This process involves selectively fusing layers of calcium powders that have been coated or mixed with polymer binders. The calcium powder mixture may be formed into layers and the polymer fused with a laser. Complex three-dimensional geometrical shapes can be automatically replicated or modified using this approach.

Abstract: A process for making bone implants from calcium phosphate powders is disclosed. This process involves selectively fusing layers of calcium powders that have been coated or mixed with polymer binders. The calcium powder mixture may be formed into layers and the polymer fused with a laser. Complex three-dimensional geometrical shapes can be automatically replicated or modified using this approach.

Abstract: A process for making bone implants from calcium phosphate powders is disclosed. This process involves selectively fusing layers of calcium powders that have been coated or mixed with polymer binders. The calcium powder mixture may be formed into layers and the polymer fused with a laser. Complex three-dimensional geometrical shapes can be automatically replicated or modified using this approach.

Abstract: A mold useful for injection molding, comprising: a porous network of metal and oxidized metal and a cured epoxy resin dispersed in the porous network. The mold can be prepared by a process comprising the sequential steps of (a) forming a mixture of a metal powder and a polymer binder; (b) heating the mixture at a temperature in the range from about 100.degree. C. to about 300.degree. C. to remove a majority of the polymer binder from the mixture; (c) heating the mixture resulting from step (b) at a temperature greater than about 300.degree. C. and less than the melting point of the metal in the presence of oxygen to oxidize at least a portion of the metal to form a self-adhering porous network of metal and oxidized metal; (d) contacting the self-adhering porous network with an epoxy resin to fill at least a portion of the porous network with epoxy resin; and (e) curing the body resulting from step (d) to form the mold. The shape of the mold can be performed by selective laser sintering of the mixture.

Abstract: Bone implants are made from calcium phosphate powders by selectively fusing layers of calcium powders that have been coated or mixed with polymer binders. The calcium powder mixture may be formed into layers and the polymer fused with a laser. Complex three-dimensional geometrical shapes can be automatically replicated or modified using this approach.

Abstract: A process for joining solid compositions, comprising placing a first solid composition having a first joining zone and a second solid composition having a second joining zone in a chamber; positioning a first gas phase, which comprises a substance that decomposes to a material that adheres to the first and second solid compositions during the process, proximate the target area; directing an energy beam to the first and second joining zones to selectively deposit material from the first gas phase on the first joining zone and the second joining zone until a joint is formed between the first and second solid compositions wherein the joint adheres to the first and second compositions at the first and second joining zones.

Abstract: A method of fabricating three-dimensional objects in a layerwise fashion, and having high structural strength and high density, is disclosed. Methods are disclosed by which nanocomposite powders of ceramic-ceramic systems, ceramic-metal systems, ceramic-polymer systems, and metal-polymer systems are produced. Disclosed examples utilize solution chemistry approaches, such as sol-gel processing, by way of which a gel is produced which is then fired and milled to form a powder suitable for selective laser sintering, where a laser fuses selected portions of layers of the powders according to a computer-aided-design data base. The ultraheterogeneity of the powder results in larger surface area and grain boundaries of the constituents, which enhances the solid state diffusion mechanism, and thus reduces the time and temperature required for sintering to occur. In addition, the higher stored metastable energy of the nanocomposite powder is believed to enhance densification during solid-phase sintering.

Abstract: A method and apparatus for selectively sintering a layer of powder to produce a part comprising a plurality of sintered layers. The apparatus includes a computer controlling a laser to direct the laser energy onto the powder to produce a sintered mass. The computer either determines or is programmed with the boundaries of the desired cross-sectional regions of the part. For each cross-section, the aim of the laser beam is scanned over a layer of powder and the beam is switched on to sinter only the powder within the boundaries of the cross-section. Powder is applied and successive layers sintered until a completed part is formed. Preferably, the powder comprises a plurality of materials having different dissociation or bonding temperatures. The powder preferably comprises blended or coated materials.

Abstract: A process for forming a copper alloy which is strengthened while maintaining good electrical and thermal conductivity by the addition of TiN or ZrN consists of external nitridation of a mechanically alloyed powder mixture followed by further mechanical alloying to break down the surface coating which forms during nitridation.

Abstract: Methods and apparatus for selectively depositing a layer of material from a gas phase to produce a part comprising a plurality of deposited layers. The apparatus includes a computer controlling a directed energy beam, such as a laser, to direct the laser energy into an unheated chamber substantially containing the gas phase to preferably produce photodecomposition or thermal decomposition of the gas phase and selectively deposit material within the boundaries of the desired cross-sectional regions of the part. At least one component of the gas phase is a vapor which condenses at a temperature above the ambient temperature of the chamber. Each such component can exist at a partial pressure no higher than its equilibrium vapor pressure at the chamber ambient temperature. For each cross section, the aim of the laser beam is scanned over a target area and the beam is switched on to deposit material within the boundaries of the cross-section.

Abstract: A method and apparatus for selectively sintering a layer of powder to produce a part comprising a plurality of sintered layers. The apparatus includes a computer controlling a laser to direct the laser energy onto the powder to produce a sintered mass. The computer either determines or is programmed with the boundaries of the desired cross-sectional regions of the part. For each cross-section, the aim of the laser beam is scanned over a layer of powder and the beam is switched on to sinter only the powder within the boundaries of the cross-section. Powder is applied and successive layers sintered until a completed part is formed. Preferably, the powder comprises a plurality of materials having different dissociation or bonding temperatures. The powder preferably comprises blended or coated materials.

Abstract: A method and apparatus for selectively sintering a layer of powder to produce a part comprising a plurality of sintered layers. The apparatus includes a computer controlling a laser to direct the laser energy onto each layer of the powder to produce a sintered mass corresponding to a cross-section of the part. For each cross-section, the aim of the laser beam is scanned over a layer of powder and the beam is switched on to sinter only the powder within the boundaries of the cross-section. Powder is applied and successive layers sintered until a completed part is formed. Also disclosed is a method of forming a part by interaction of material in the powder layer with reactants in the surrounding atmosphere, at locations of the powder irradiated by the energy, or laser, beam. The reaction may be nitridation, oxidation or carburization of the powder, with the product being a chemical compound of one or more constituents in the powder with one or more gases in the atmosphere.

Abstract: A method and apparatus for selectively depositing a layer of material from a gas phase to produce a part comprising a plurality of deposited layers. The apparatus includes a computer controlling a directed energy beam, such as a laser, to direct the laser energy into a chamber substantially containing the gas phase to preferably produce photodecomposition or thermal decomposition of the gas phase and selectively deposit material within the boundaries of the desired cross-sectional regions of the part. For each cross section, the aim of the laser beam is scanned over a target area and the beam is switched on to deposit material within the boundaries of the cross-section. Each subsequent layer is joined to the immediately preceding layer to produce a part comprising a plurality of joined layers. In an alternate embodiment of the present invention, a gas phase is condensed on a surface and a laser beam is used to selectively evaporate, transform, activate or decompose material in each layer.

Abstract: A method and apparatus for selectively sintering a layer of powder to produce a part comprising a plurality of sintered layers. The apparatus includes a computer controlling a laser to direct the laser energy onto the powder to produce a sintered mass. The computer either determines or is programmed with the boundaries of the desired cross-sectional regions of the part. For each cross-section, the aim of the laser beam is scanned over a layer of powder and the beam is switched on to sinter only the powder within the boundaries of the cross-section. Powder is applied and successive layers sintered until a completed part is formed. Preferably, the powder comprises a plurality of materials having different dissociation or bonding temperatures.

Abstract: A method and apparatus for selectively sintering a layer of powder to produce a part comprising a plurality of sintered layers. The apparatus includes a computer controlling a laser to direct the laser energy onto the powder to produce a sintered mass. The computer either determines or is programmed with the boundaries of the desired cross-sectional regions of the part. For each cross-section, the aim of the laser beam is scanned over a layer of powder and the beam is switched on to sinter only the powder within the boundaries of the cross-section. Powder is applied and successive layers sintered until a completed part is formed. Preferably, the powder comprises a plurality of materials having different dissociation or bonding temperatures.