Method and apparatus for producing parts by selective sintering

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 dispensing mechanism includes a drum which is moved horizontally across the target area and counter-rotated to smooth and distribute the powder in an even layer across the target area. A downdraft system provides controlled temperature air flow through the target area to moderate powder temperature during sintering.Board of Regents, University of Texas Syste

Method for producing parts by selective sintering

A method and apparatus for selectively sintering a layer of powder to produce a part as 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 dispensing mechanism includes a drum which is moved horizontally across the target area and counter-rotated to smooth and distribute the powder in an even layer across the target area. A downdraft system provides controlled temperature air flow through the target area to moderate powder temperature during sintering.Board of Regents, University of Texas Syste

On dimensional stabilities: Modeling of the Bonus-Z during the SLS Process

This work is a first step towards the prediction of the dimensions and thermomechanical properties ofparts made with the Selective Laser Sintering (SLS) technology. An important variation of the dimensions is found in the Z-direction of the build. This phenomenon is known as the "Bonus-Z" where material properties differ from those in the rest of the part due to a non-homogeneous sintering. The focus of this work is the characterization and the modeling of the bonus-Z phenomenon, by relating it to the energy input. The polymer powder used in this study is polycarbonate.Mechanical Engineerin

Multiple material systems for selective beam sintering

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.Board of Regents, University of Texas Syste

Method and apparatus for producing parts by selective sintering

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. The powder can comprise either plastic, metal, ceramic, or polymer substance. In the preferred embodiment, the aim of the laser is directed in a continuous raster scan and the laser turned on when the beam is aimed with the boundaries of the particular cross-section being formed.Board of Regents, University of Texas Syste

Method and apparatus for producing parts by selective sintering

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 dispensing mechanism includes a drum which is moved horizontally across the target area and counter-rotated to smooth and distribute the powder in an even layer across the target area. A downdraft system provides controlled temperature air flow through the target area to moderate powder temperature during sintering.Board of Regents, University of Texas Syste

Method for producing parts by infiltration of porous intermediate parts

A method and apparatus for selectively sintering a layer of powder to produce a part as 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 dispensing mechanism includes a drum which is moved horizontally across the target area and counter-rotated to smooth and distribute the powder in an even layer across the target area. A downdraft system provides controlled temperature air flow through the target area to moderate powder temperature during sintering.Board of Regents, University of Texas Syste

Selective laser sintering with assisted powder handling

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 is deposited to the target area of the laser and attains high bulk density during sintering.Board of Regents, University of Texas Syste

Multiple material systems for selective beam sintering

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 onto 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.Board of Regents, University of Texas Syste

Professionals and interfamily violence against children and adolescents: in between legal and conceptual precepts

OBJETIVO Identificar, com base no discurso dos profissionais, suas concepções a respeito da violência intrafamiliar contra crianças e adolescentes. MÉTODO Estudo qualitativo, realizado com 15 profissionais, que tiveram sob seus cuidados crianças e adolescentes atendidas em decorrência da violência intrafamiliar. Os dados foram coletados entre novembro de 2013 e março de 2015, por meio de entrevistas semiestruturadas. Os dados foram organizados e analisados utilizando a técnica de Análise Textual Discursiva. RESULTADOS O discurso dos profissionais colocou em evidência que alguns aspectos legais em relação ao manejo da violência intrafamiliar contra crianças e adolescentes são negligenciados, omissão respaldada pela justificativa dos profissionais de preservar a família. Destaca-se o confronto entre a concepção de família como cuidadora e a família que violenta os filhos, além do posicionamento dos profissionais, os quais não incluem a família e o agressor nos processos de intervenção frente às situações de violência intrafamiliar atendidas nos serviços. CONCLUSÃO Atuar frente à violência intrafamiliar requer do profissional romper com algumas concepções preestabelecidas para colocar em evidência as reais necessidades de vítimas e famílias.OBJETIVO Identificar, con base en el discurso de los profesionales, sus concepciones con respecto a la violencia intrafamiliar contra niños y adolescentes. MÉTODO Estudio cualitativo, realizado con 15 profesionales que tuvieron bajo sus cuidados a niños y adolescentes atendidos en consecuencia de la violencia intrafamiliar. Se recogieron los datos entre noviembre de 2013 y marzo de 2015, mediante entrevistas semiestructuradas. Los datos fueron organizados y analizados empleando la técnica de Análisis Textual Discursivo. RESULTADOS El discurso de los profesionales puso en evidencia que se descuidan algunos aspectos legales con respecto al manejo de la violencia intrafamiliar contra niños y adolescentes, omisión esa respaldada por la justificación de los profesionales de preservar a la familia. Se destaca el confronto entre la concepción de familia como cuidadora y la familia que violenta a los hijos, además de la postura de los profesionales, quienes no incluyen a la familia y al agresor en los procesos de intervención frente a las situaciones de violencia intrafamiliar atendidas en los servicios. CONCLUSIÓN Actuar ante la violencia intrafamiliar requiere que el profesional rompa algunas concepciones prestablecidas para poner en evidencia las reales necesidades de víctimas y familias.OBJECTIVE To identify the conceptions of professionals regarding interfamily violence against children and adolescents. METHOD A qualitative study conducted with 15 professionals who had taken children and adolescents under their care as a result of interfamily violence. Data were collected between November, 2013, and March, 2015, through semi-structured interviews. Data were organized and analyzed using the Textual Discourse Analysis technique. RESULTS The professional discourse highlighted that some legal aspects regarding the handling of interfamily violence against children and adolescents are neglected; an omission supported by the justification of professionals to preserve the family. We highlight the confrontation between the concept of family as a caregiver and the family that commits violence against children, in addition to the positioning of professionals, which does not include the family or the aggressor in the intervention process in facing situations of interfamily violence attended to by the services. CONCLUSION Acting against interfamily violence requires professionals to do away with some pre-established concepts in ordee to put the actual needs of victims and families into evidence