METALS

• Metals are opaque, lustrous elements that are good conductors of heat and electricity.
• ferrous metals contain iron
• non-ferrous metals, are much lighter than ferrous metals,
• Annealing

  • is a softening process in which metals are heated and then allowed to cool slowly.
• Quenching

  • is the process in which metals are cooled rapidly after heating
• TEMPERING

  • Gently heating a hardened metal and allowing it to cool slowly,
• COLD WORKING

  • When a metal is bent or shaped, dislocations are generated and move. As the number of

  dislocations in the crystal increases, they will get tangled or pinned and will not be able to

  move.
• FORGING

  • Is controlled, plastic deformation on working of metals into predetermined shapes by

  means of pressure or impact blows, or a combination of both.
• ROLLING

  • It is the process of when work material is plastically deformed by compressive forces

  between two constantly spinning rolls.
• DRAWING

  • Is a manufacturing process that forms metal work stock by reducing its cross-

  section. This is accomplished by forcing the work through a mold (die), of smaller

  cross-sectional area than the work.
• In extrusion the work is pushed

  through the die opening, where in drawing it is pulled through.
• STAMPING

  • Is a manufacturing process also known as pressing, includes a variety of sheet-metal

  forming manufacturing processes, such as punching using a machine press or stamping

  press
• BENDING

  • Bending is a common metalworking technique used to process sheet metal.
• BLANKING

  • Is a shearing process where a punch and die are used to create a “blank” from sheet metal or strip.
• COINING

  • Is a form of precision stamping in which a work-piece is subjected to a sufficiently high stress to

  induce flow on the surface of the material.
• EMBOSSING

  • Is a process for producing raised or sunken designs or relief in sheet metal
• EXTRUSION

  • is a metal forming process in which a work piece, of a certain length and cross section, is

  forced to flow through a die of a smaller cross-sectional area, thus forming the work to

  the new cross section.
• CASTING

  • A mold is formed into the geometric shape of a desired part. Molten metal is then poured

  into the mold, the mold holds this material in shape as it solidifies.
• ALUMINUM

  • Is a soft, nonmagnetic silvery metal
• “Alclad” is a term applied to certain aluminum products,
• IRON

  • tough, malleable silvery-white metal that is soft and ductile as copper
• CAST IRON

  • is an iron-carbon alloy that contains more than 1.7% carbon
• WROUGHT IRON

  • is almost pure iron with less than 0.1% carbon,
• STEEL

  • The word “steel” usually refers to plain carbon steel
• two types of steel

  • WROUGHT CARBON STEEL
  • ALLOY STEEL
• COPPER

  • is ductile, malleable, nonmagnetic metal with a characteristic bright, reddish brown color.

  • has the highest electrical and thermal conductivity of any substances
• On exposure it soon reacts to form a surface layer of an insoluble green salt; this green color on copper is known as its patina.
• TIN

  • is a soft, ductile, malleable, bluish-white metal.
• ZINC

  • is medium hard, bluish-white metal

  • is characterized by brittleness and low strength.
• BRASS

  • fundamentally an alloy of copper and zinc
• BRONZE

  • True bronze is an alloy of copper and tin
• CHROMIUM

  • is a steel-white metal which takes a brilliant polish and is harder than cobalt or nickel.
• NICKEL

  • Is an inert silvery metal and resistant to strong alkalis and to most acids.• It resembles iron in strength and toughness
• LEAD

  • Lead is a blue-gray, soft, very heavy metal (the heaviest of the common metals).
• Soldering

  • is a method to join metals, to make electrical connections, to seal joints hermetically with

  another lower melting metal or alloy called the solder.
• Soldering can be divided into major types

  • tin-lead
  • tin-lead-antimony
  • silver-lead.
• Brazing

  • is a type of soldering in which the operating temperatures are higher
• Welding

  • \is the process by which two metals are so joined that there is an actual union of the

  interatomic bonds.
• Rivets

  • are devices used to join or fasten the metals.
• STEEL BARS

  • Reinforcement for concrete construction is mostly in the form of steel bars