Treball sobre el crom, inclou:
característiques generals
història
abundància i obtenció
aplicacions
compostos
isòtops
paper biològic
precaucions
consideracions
econòmiques
SECTION VII: EFFICIENT WASTE-TO-ENERGY
“Fly ash from incinerators: raw material for building materials” by Mr. Xavier Elias, Director of the By-Product Exchange Market, General Council of Chambers of Commerce in Catalonia
Roll forming, also known as contour roll forming, is a continuous process that forms metal sheet or coil stock into desired shapes by passing it through a series of roller dies. The stock is progressively worked through two or more stations until the finished shape is produced. Auxiliary operations like notching, slotting, punching, and embossing can be combined with roll forming. Contour roll forming is used across many industries like automotive, building, furniture, appliances, medical equipment, railcars, aircraft, and HVAC to produce a variety of metal products. It requires less force than other forming methods and allows theoretically unlimited length, while still strengthening the metal through controlled plastic deformation.
For over 85 years, Roller Die + Forming has been providing custom roll formed, stamped, powder coated and assembled metal parts, using lean manufacturing processes.
This document summarizes sheet metal forming processes like shearing, punching, bending, and deep drawing. It discusses the basic techniques, important parameters, and applications for each process. Key points include that low-carbon steel is commonly used for its strength and formability. Shearing involves cutting a blank from a sheet using a punch and die. Minimum bend radius depends on the sheet thickness and material properties to prevent cracking. Deep drawing is used to form containers and other cylindrical or box-shaped parts, with formability determined by the limiting drawing ratio.
Este documento describe los diferentes tipos de tratamientos que se pueden aplicar a los metales para mejorar sus propiedades, incluyendo tratamientos térmicos, termoquímicos, mecánicos, termomecánicos y superficiales. Define cada tipo de tratamiento y proporciona ejemplos como la cementación, nitruración, temple y revenido. El objetivo general de los tratamientos es mejorar la dureza, resistencia y otras propiedades mecánicas de los metales.
The document describes several common composite manufacturing techniques including wet lay-up, vacuum bagging, compression moulding, filament winding, pultrusion, and resin transfer moulding. Each technique involves different processes for combining fibres and resin such as applying layers by hand, using pressure and heat, winding fibres onto a rotating mandrel, pulling fibres through a resin bath, or injecting resin into a mould containing dry fibres. The techniques are suited for different part geometries and production volumes.
Explosive forming is a metal shaping technique that uses an explosive charge to generate high forming pressures. There are two main methods - the stand off method places a metal plate over a die and positions an explosive above the plate, while the contact method places the explosive in direct contact with the workpiece. The rapid conversion of the explosive to gas produces a shock wave with pressures up to several million psi that can form metal sheets into complex shapes in a single operation, making it suitable for aerospace applications requiring large or low-quantity customized parts.
This document discusses root canal preparation techniques presented by Dr. Fasahath Ahmed Butt. It covers the objectives of root canal preparations, which are to completely remove pulp tissue and bacteria while maintaining the original root canal anatomy. The main types of preparations discussed are crown-down, step-back, and hybrid techniques. For each technique, the document outlines the basic process and advantages and disadvantages. It also briefly covers different filing techniques used in root canal preparations like watch winding, reaming, and balanced force.
Este documento describe los principales métodos de conformación de metales como el forjado y la extrusión. Explica que el forjado involucra calentar el metal y deformarlo plásticamente aplicando presión, ya sea con martillos o prensas. También describe las herramientas comunes del forjado como yunques, tenazas y fraguas. El documento analiza el forjado en caliente y en frío, así como el forjado en matriz abierta y cerrada.
The document provides an overview of the metal spinning process. It discusses the history and classification of different metal spinning techniques. The basic metal spinning process involves clamping a metal blank between a spinning mandrel and follower, and using specially designed tools to form the blank into an axially symmetric product while it rotates at high speeds. Key aspects covered include the mechanics of cone spinning, use of multi-pass spinning for small cone angles, mandrel and tool design, lubricants, common spinning machines, advantages over other forming processes, and applications.
El documento describe los principales tipos de mecanizado y procesos de fabricación sin arranque de viruta. El mecanizado implica eliminar material de una pieza mediante el uso de herramientas de corte y genera virutas, mientras que los procesos sin arranque de viruta deforman el material sin separarlo. Se explican procesos como torneado, taladrado, fresado, forja, laminado y doblado.
Metal forming processes are used to shape metals into useful products. Rolling is the most common forming process and accounts for around 90% of metal forming. It involves passing metal between rolls to reduce thickness or change cross-section. Forging uses dies and compression to shape hot or cold metal. Extrusion forces heated metal through a die to create shapes like rods, tubes and structural sections. Drawing pulls metal through a die to make wires, rods and tubes from both hot and cold workpieces. Deep drawing specifically makes cylindrical parts like cups from sheet metal.
Treball sobre el crom, inclou:
característiques generals
història
abundància i obtenció
aplicacions
compostos
isòtops
paper biològic
precaucions
consideracions
econòmiques
SECTION VII: EFFICIENT WASTE-TO-ENERGY
“Fly ash from incinerators: raw material for building materials” by Mr. Xavier Elias, Director of the By-Product Exchange Market, General Council of Chambers of Commerce in Catalonia
Roll forming, also known as contour roll forming, is a continuous process that forms metal sheet or coil stock into desired shapes by passing it through a series of roller dies. The stock is progressively worked through two or more stations until the finished shape is produced. Auxiliary operations like notching, slotting, punching, and embossing can be combined with roll forming. Contour roll forming is used across many industries like automotive, building, furniture, appliances, medical equipment, railcars, aircraft, and HVAC to produce a variety of metal products. It requires less force than other forming methods and allows theoretically unlimited length, while still strengthening the metal through controlled plastic deformation.
For over 85 years, Roller Die + Forming has been providing custom roll formed, stamped, powder coated and assembled metal parts, using lean manufacturing processes.
This document summarizes sheet metal forming processes like shearing, punching, bending, and deep drawing. It discusses the basic techniques, important parameters, and applications for each process. Key points include that low-carbon steel is commonly used for its strength and formability. Shearing involves cutting a blank from a sheet using a punch and die. Minimum bend radius depends on the sheet thickness and material properties to prevent cracking. Deep drawing is used to form containers and other cylindrical or box-shaped parts, with formability determined by the limiting drawing ratio.
Este documento describe los diferentes tipos de tratamientos que se pueden aplicar a los metales para mejorar sus propiedades, incluyendo tratamientos térmicos, termoquímicos, mecánicos, termomecánicos y superficiales. Define cada tipo de tratamiento y proporciona ejemplos como la cementación, nitruración, temple y revenido. El objetivo general de los tratamientos es mejorar la dureza, resistencia y otras propiedades mecánicas de los metales.
The document describes several common composite manufacturing techniques including wet lay-up, vacuum bagging, compression moulding, filament winding, pultrusion, and resin transfer moulding. Each technique involves different processes for combining fibres and resin such as applying layers by hand, using pressure and heat, winding fibres onto a rotating mandrel, pulling fibres through a resin bath, or injecting resin into a mould containing dry fibres. The techniques are suited for different part geometries and production volumes.
Explosive forming is a metal shaping technique that uses an explosive charge to generate high forming pressures. There are two main methods - the stand off method places a metal plate over a die and positions an explosive above the plate, while the contact method places the explosive in direct contact with the workpiece. The rapid conversion of the explosive to gas produces a shock wave with pressures up to several million psi that can form metal sheets into complex shapes in a single operation, making it suitable for aerospace applications requiring large or low-quantity customized parts.
This document discusses root canal preparation techniques presented by Dr. Fasahath Ahmed Butt. It covers the objectives of root canal preparations, which are to completely remove pulp tissue and bacteria while maintaining the original root canal anatomy. The main types of preparations discussed are crown-down, step-back, and hybrid techniques. For each technique, the document outlines the basic process and advantages and disadvantages. It also briefly covers different filing techniques used in root canal preparations like watch winding, reaming, and balanced force.
Este documento describe los principales métodos de conformación de metales como el forjado y la extrusión. Explica que el forjado involucra calentar el metal y deformarlo plásticamente aplicando presión, ya sea con martillos o prensas. También describe las herramientas comunes del forjado como yunques, tenazas y fraguas. El documento analiza el forjado en caliente y en frío, así como el forjado en matriz abierta y cerrada.
The document provides an overview of the metal spinning process. It discusses the history and classification of different metal spinning techniques. The basic metal spinning process involves clamping a metal blank between a spinning mandrel and follower, and using specially designed tools to form the blank into an axially symmetric product while it rotates at high speeds. Key aspects covered include the mechanics of cone spinning, use of multi-pass spinning for small cone angles, mandrel and tool design, lubricants, common spinning machines, advantages over other forming processes, and applications.
El documento describe los principales tipos de mecanizado y procesos de fabricación sin arranque de viruta. El mecanizado implica eliminar material de una pieza mediante el uso de herramientas de corte y genera virutas, mientras que los procesos sin arranque de viruta deforman el material sin separarlo. Se explican procesos como torneado, taladrado, fresado, forja, laminado y doblado.
Metal forming processes are used to shape metals into useful products. Rolling is the most common forming process and accounts for around 90% of metal forming. It involves passing metal between rolls to reduce thickness or change cross-section. Forging uses dies and compression to shape hot or cold metal. Extrusion forces heated metal through a die to create shapes like rods, tubes and structural sections. Drawing pulls metal through a die to make wires, rods and tubes from both hot and cold workpieces. Deep drawing specifically makes cylindrical parts like cups from sheet metal.
The document discusses cleaning and shaping objectives, principles, and techniques in endodontics. It aims to remove canal contents, irregularities, and obstructions while maintaining the original canal anatomy and foramen size. Cleaning is achieved through instrumentation and irrigation, assessed by debris removal and smooth canal walls. Shaping provides a continuously tapering preparation from crown to apex. Working length is 1 mm from the radiographic apex. Techniques include step-back preparation from apex to crown in phases using increasingly larger instruments supplemented by irrigation and recapitulation.
This document discusses rolling processes used to shape metals. It describes rolling as a bulk deformation process that reduces thickness or changes cross-section of a workpiece using compressive forces from rotating rolls. Hot rolling involves heating metal above its recrystallization temperature before rolling, allowing larger deformation and grain refinement. Cold rolling increases strength but reduces ductility, so heat treatment is often required after. The document provides details on advantages and limitations of both hot and cold rolling processes.
1. Sheet metal forming operations include bending, stretching, deep drawing, and other processes where sheets are formed. Bending involves shaping a straight length into a curve and can be done using presses or rolls.
2. Deep drawing uses a die and punch to shape flat sheets into cup-shaped parts. Stretch forming clamps sheet edges and stretches the sheet over a die into the desired shape.
3. Successful forming requires considering the material properties, die and process parameters to avoid defects like cracks, wrinkles, and non-uniform thinning. Minimum bend radii, lubrication, and holding pressure all impact the quality of formed parts.
Este documento describe los procesos de extrusión de metales en caliente y en frío. La extrusión es un proceso para obtener formas continuas al forzar un material a través de un dado usando prensas hidráulicas o mecánicas. La extrusión en caliente permite producir perfiles de sección constante de manera económica y en lotes pequeños usando aluminio, cobre, magnesio y aleaciones. La extrusión en frío produce piezas con zonas largas de tubo mediante golpes de un punzón en una matriz y
Este documento trata sobre los procesos de conformado de metales. Explica que el conformado involucra la deformación plástica de piezas metálicas usando herramientas como dados. También describe algunos procesos de conformado comunes como laminación en caliente, forja, estampado y doblado. Finalmente, discute factores como la temperatura y propiedades del metal que afectan el conformado exitoso.
This document discusses properties and techniques related to metals. It begins by describing the common uses of metals in transportation, telecommunications, machinery, construction and manufacturing. It then discusses three types of metal properties: physical, chemical, and ecological. The document also outlines the processes of obtaining metals through surface and underground mining. Finally, it explores various shaping techniques for metals such as casting, powder metallurgy, and describes cutting, joining and finishing processes.
The document summarizes various properties and characteristics of metals. It discusses physical properties like strength, ductility and conductivity. It also covers chemical properties such as oxidation and toxicity. Metals are obtained through surface or underground mining. Common ferrous metals include iron, steel and cast iron. The document also describes some heavy metals like lead, tin, zinc and copper, as well as alloys like bronze and brass. It outlines techniques for shaping metals, including rolling, extrusion, forging, casting and powder metallurgy. Permanent joining is done through riveting, welding or adhesives, while temporary joins use nuts, bolts or other fasteners. Finishing techniques remove imperfections and protect surfaces.
Rolling is a metal forming process that uses rolls to reduce the thickness and increase the length of metal workpieces. It can be done hot or cold. Hot rolling occurs above the metal's recrystallization temperature and results in a more uniform structure, while cold rolling occurs at room temperature and produces closer tolerances and a better surface finish. The document defines various products of rolling like billets, blooms, slabs, plates, sheets and strips based on their dimensions. It also describes different types of rolling processes like continuous, transverse, shape, ring and thread rolling as well as the types of mills used like two-high, three-high and four-high mills.
Tema intro a la programación (robomind) (informática 4ºeso)jribalt1
Este documento introduce la programación y el lenguaje de programación RoboMind. Explica que un programa de control define el funcionamiento de una máquina mediante instrucciones. Luego describe las instrucciones básicas de movimiento, visión, pintura y recogida de objetos en RoboMind, así como estructuras como bucles y condicionales para controlar el flujo del programa.
1. Wolframi
Paul Hozan Marian
1r Batx
Pep Ribalta
IES Quercus
2. Introducció
El wolframi o tambe anomenat tungstè es un element
químic de nombre 74 a la taula periodica y es
representa amb la lletra W.
Es un metall escas a l’escorça terrestre es troba en forma
de d’oxid i de sals en certs minerals. De color gris
acerat, molt dur i dens te el punt de fusió mes elevat de
tots els elements
3. Com s’obte el wolframi
Per a extreure l'element del seu mena, es fon aquest amb
carbonat de sodi obtenint-se wolframat de sodi,
Na2WO4. El wolframat de sodi soluble s'extreu
després amb aigua calenta i es tracta amb àcid
clorhídric per a aconseguir àcid wolfrámic, H2WO4.
Aquest últim compost, una vegada rentat i assecat,
forma l'òxid WO3, que es redueix amb hidrogen en un
forn elèctric. La fina pols obtinguda es torna a escalfar
en motlles en una atmosfera d'hidrogen, i es premsa en
forma de barres que s'enrotllen i martellegen a alta
temperatura per a fer-les compactes i dúctils.
4. Caracteristiques del wolframi
Nombre atomic : 74
Massa atomica : 183,84uma
Punt de fusió : 3410°C
Punt de ebullició : 5930°C
Densitat : 19250 kg/m3
5. Propietats del wolframi
Es molt dur
Es molt dens
Es maleable
Resistent a la corrosió
Gran resistencia electrica
Punt de fusió mes alt
Molt resistent als acids
7. Aplicacions del wolframi i els seus
alitges
El wolframi i els seus aliatges s'emprenen en filaments de
llums elèctrics, tubs electrònics i de televisió i en la tècnica
d'evaporació de metalls.
S'utilitza com blanc de RAJOS X.
Es fa srvir en bobines i altres elements de calefacció de forns
elèctrics i altres materials que requereixen treballar a altes
temperatures i ser resistents a la corrosió.
S'utilitza en la indústria aeronàutica: caps de coets, motors.
Els wolframat de calci i de magnesi s‘utilitza en llums
fluorescents.
8. El wolframat sòdic s'utilitza per a fabricar teixits
incombustibles.
El carbur de wolframi té gran importància per a treballar
els metalls: cort, torns, mineries, petroli, etc.
El disulfur de wolframi és un lubrificant sec empleat a
altes temperatures.
El trióxid de wolframi s'utilitza en pintures i ceràmica.