Understanding the Properties and Applications of Metals

Properties of Metals

• Good Conductors of Heat
• Good Conductors of Electricity
• Resistant: They withstand forces of compression, traction, and flexion.
• Pliers: They can withstand blows without breaking.

Differences Between Soft Iron and Steel

Soft iron is considered pure, while steel is malleable, ductile, and oxidizes (reacts with oxygen) easily. Steel tongs are common.

Foundries produce materials that are less ductile and less tenacious than steel but harder. Carbon provides hardness but increases fragility.

Non-Ferrous Materials

Examples include:

• Brass
• Bronze (copper and tin)
• Aluminum
• Copper
• Magnesium
• Titanium

Properties and Applications of Copper and Aluminum

Copper: Red, excellent electrical conductor, resistant to thermal corrosion, easily welded, very ductile, and malleable.

• Electrical wiring
• Pipes
• Electronics

Aluminum: White, shiny, lightweight, good resistance to corrosion, non-toxic, used in packaging, inexpensive, and soft.

• Foil
• Cans
• Aircraft parts

Brass and Bronze

Brass: Yellow, very ductile and malleable, with a tensile strength of approximately 53 kg/mm².

Bronze: Darker, more resistant than brass, and has good corrosion resistance. When cast, it is very fluid, making it easy to pour into a mold.

Methods to Join Metals

• Welding
• Rivets
• Screw connections

Metal Drawing Process

Metal drawing involves starting with a metal plate superimposed on a matrix, which is deformed by the action of a large punch. This system is used to manufacture car bodies and drink cans.

Principal Machines Used in Workshops

• Boring
• Milling
• Turning
• Parting
• Cam

Metal Casting Explained

Molten metal is poured into a mold and allowed to cool. In shaping, pressure is applied to moving parts such as lamination rollers or hydraulic presses.

Materials Used for Manufacturing Parts

• Gold Band: Gold is melted into a mold, and upon cooling, the ring is removed.
• Steel Beam: Obtained by heating steel, which is then shaped by rollers.
• Gear: A cylindrical shape is created on a lathe and milling machine, followed by the practice of cutting teeth.
• Car Body: Typically made from steel sheet, shaped by deep drawing and joined by spot welds.
• Aluminum Window: Extrusion is used, where the metal is made liquid, and then the profile is assembled.
• Radiator: Made by casting and molding, heated and shaped in specific containers.