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Ferrous Materials or Metals

Ferrous metals are those metals that are composed primarily of iron and have magnetic properties in them. Some common ferrous metals include alloy steel, carbon steel, cast iron, and wrought iron. These metals are easily recycled.

Characteristics of Ferrous Materials

  1. Ferrous metals include mild steel, carbon steel, stainless steel, cast iron, and wrought iron. These metals are used primarily for their tensile strength and durability, especially the mild steel that helps support the world’s tallest skyscrapers and longest bridges.
  2. You can also find ferrous metals in home construction, industrial containers, large-scale piping, automobiles, railroad and transportation rails, most tools and implements you use around the house, and knives you use for cooking at home.
  3. Because of the high amounts of carbon used in creating them, most ferrous metals and alloys are vulnerable to rust when exposed to the elements.
  4. While this is not true for wrought iron, which is so pure in iron that it resists rust, or stainless steel, which is protected by its high chromium content, it is a good rule of thumb that if you see rust, it is a ferrous metal.
  5. Most ferrous metals also have magnetic properties, which makes them very useful in the creation of large engines and electrical appliances.
  6. The reason you can stick your child’s artwork on the refrigerator with that magnet is because of the phone number of the local pizzeria? Ferrous metals.
  7. More importantly, ferrous metals make up the majority of recycled materials in the world.

Properties of Ferrous Materials or Metals

  • Cast Iron: Hard skin, softer underneath, but brittle, corrodes as it oxidizes
  • Mild steel: Hard, ductile, malleable, good tensile strength, low corrosion resistance.
  • High Carbon Steel: Even harder than medium carbon steel and more brittle, it can be heat treated to make it harder and more resistant.
  • Stainless Steel: Hard and tough, wear and corrosion resistant

Examples of Ferrous Materials

  1. Cast iron foundry.
  2. Ornamental wrought iron.
  3. Mild steel Tool steel, used for making tools.
  4. Stainless steel (can be ferrous or non-ferrous depending on the iron content).
  5. Plated steel, similar to mild steel; it has a galvanized coating that protects it from rust.
  6. An easy trick to see if a metal is ferrous or non-ferrous is to see if a magnet will adhere to it. A magnet will stick to a piece of ferrous metal because of the iron content.

Classification of Ferrous Materials

Cast Irons

  • Grey Irons
  • Grey cast iron contains graphite in the form of flakes. Called after its fractured gray surface.
  • Weak and brittle in tension.
  • Excellent cushioning capacity, wear resistance.

Malleable Iron

  • Obtained by heat treatment of white iron over a prolonged period that causes the decomposition of cementite into graphite.
  • Reasonable resistance and improved ductility (malleable)

Ductile Iron

  • The addition of Mg and/or Cerium to the grey iron converts the graphite flakes to nodules.
  • Usually a perlite matrix.
  • The charges are stronger and much more ductile than gray iron as the stress concentration points at the ends of the flakes are eliminated.

Compacted Graphite Iron

  • CGI graphite is produced as blunt or worm-shaped flakes
  • The microstructure and properties are between gray and ductile iron.
  • With relatively high thermal conductivity, good resistance to thermal shock, lower oxidation at elevated temperatures

White Iron

  • Very hard and brittle.
  • Used as an intermediate to produce malleable cast iron
  • Simple Carbon Steels:

High Carbon

  • The high C content provides high hardness and strength.
  • Used in hardened and tempered state.
  • Used as tool and die steels due to the high hardness and wear resistance property.

Medium Carbon

  • It can be treated with heat: austenization, cooling and then tempering.
  • Widely used in temperate conditions – tempered martensite.
  • Typical applications: railway wheels and rails, gears, crankshafts.

Low Carbon

  • Flat carbon steels: very low content of alloy elements and small amounts of Mn.
  • Most abundant steel is low-carbon steel, the best quantity produced; less expensive.
  • Does not respond to heat treatment; cold work required to improve strength.
  • Alloy steels: low alloy steels, HSLA steels, advanced high strength steels, stainless steels, tool steels

Uses and Applications of Ferrous Materials

Its application is numerous, but can be reduced to three of its classes; Wrought iron, steel and cast iron.

  1. As wrought iron, ferrous metals can be used in structural engineering, as fencing, can also be used in the manufacture of kitchen utensils, although this is gradually falling into disuse. It can also be used to make engine crankshafts, etc.
  2. As cast iron, it can be used to make engine blocks, due to its ability to resist heat and high temperatures. It can also be used as the base for large machines due to its good damping property.
  3. As steel, it can be used in the automotive industry as valves in cylinder heads, car axles
  4. It can also be used to make kitchen utensils, interior decoration, sinks, tools, among others.

Uses of Ferrous Materials in Construction

Chosen for their durability, strength and weather resistance, metals used in the construction industry serve a wide range of functions. The most common are carbon steel, aluminum, copper and stainless steel tubes, each with its particular qualities and ideal uses. As a whole, however, these metals are omnipresent in the world of buildings and architecture, in both small and large applications.

Carbon steel is an alloy that is highly valued in the construction industry for its hardness and strength. It is generally used to make structural frame beams, plates for road construction, and rectangular tubes for welded bed frames and bridges. Aluminum is also commonly used in the industry because it is corrosion resistant, highly conductive, and ductile. Because it is weather resistant, the metal is used in windows, doors, and cables, as well as in outdoor signage and street lighting.

The metal is processed into sheets, tubes and castings, and is also used to build cars and trucks, as well as bicycles and marine vessels. Aluminum HVAC ducts, roofs, walls and handles are also frequently found in the construction industry. Copper pipe, which comes in two main types, is often used to construct pipes in buildings. Rigid copper pipe is ideal for hot and cold water piping in buildings.

Stainless steel is among the oldest known construction materials. It was used centuries ago to build structures that still stand today, thanks to the metal’s corrosion and stain-resistant properties. Some of the most famous architectural structures, such as the Chrysler Building in New York City, rely on stainless steel for strength, durability and reliability.

Non-Ferrous Materials

Non-ferrous metals do not contain iron. Some common non-ferrous metals are aluminum, duralumin, copper, zinc, brass, gold and tin. Non-ferrous metals, or metals without significant iron content, are also strong. However, they are lighter than ferrous metals and cannot suspend similar loads. They are also more malleable, and both features can be an advantage.

They were the first metals to be used in the art of metallurgy. Silver, copper, and gold have been collected and used since ancient times as currency, jewelry, crucibles, other sacred objects, weapons, and architectural components.

Characteristics of Non-Ferrous Metals

  1. Non-ferrous metals include aluminum, brass, copper, nickel, tin, lead, and zinc, as well as precious metals such as gold and silver.
  2. While non-ferrous metals can provide strength, they are primarily used when their differences from ferrous metals can provide an advantage.
  3. For example, non-ferrous metals are much more malleable than ferrous metals. Non-ferrous metals are also much lighter, so they are suitable for use when strength is needed, but weight is a factor, such as in the aviation or canning industries.
  4. Because they don’t contain iron, non-ferrous metals have greater resistance to rust and corrosion, so you’ll find these materials in use for gutters, water pipes, roofs, and road signs.
  5. Finally, they are also non-magnetic, making them perfect for use in small electronic devices and as electrical wiring.
  6. In terms of recycling, aluminum is the third most recycled material in the world. However, many other non-ferrous materials such as copper, brass and lead are relatively scarce, and metallurgists rely heavily on recycling waste materials to make new ones.

Properties of Non-Ferrous Materials

  • Corrosion resistant.
  • High resistance / weight ratio at room temperature.
  • Resistant to corrosion.
  • High electrical conductivity (Volume by volume, 60% copper).
  • Excellent thermal conductor.
  • Lightweight.
  • High ductility.
  • Must be annealed frequently if it works in cold.
  • Good solderability.
  • Good modulus of elasticity.
  • Good color and color imparting properties.

Examples of Non-Ferrous Metals and Uses

Important non-ferrous metals include:

  • Aluminum: The third most abundant element (after oxygen and silicon) and the most abundant metal in the earth’s crust. Aluminum is used in the construction of airplanes, light vehicles and stairs. Roofing materials, window frames, boilers, stoves and kitchen utensils. Lead – Lead metal has a bluish white color after it is recently cut, but soon turns a dull grayish color when exposed to air. The use of lead Storage battery plates, covering electrical cables, x-rays, shielding of radioactive material
  • Tin: White, malleable metal that oxidizes quickly when left at room temperature and changes color to a more opaque gray. Characterized by its resistance to corrosion. You can find it in alloys and is used for coating other types of metals to protect them from corrosion.
  • Zinc: It is a good conductor of electricity and burns in the air with a bright blue-green flame that produces white clouds of rust. Zinc is used to galvanize iron to inhibit corrosion. Zinc forms many alloys with other metals such as brass, German silver, nickel silver, typewriter metal, and solder.
  • Copper: is used mainly in the manufacture of cables, wires and electrical conductors. Its other uses are water and central heating pipes and cylinders, printed circuit boards, and special roofing.
  • Nickel: Nickel is a high density, high strength metal with good ductility and excellent corrosion resistance and high temperature properties. Nor does it have unique properties that include its excellent catalytic properties. Nickel Catalyst for Fuel Cells: Nickelcobalt is seen as a low cost substitute for platinum catalysts. Two-thirds of all nickel produced goes into stainless steel production. It is also widely used in multi-part electroplating in a variety of applications. Ni-base super alloys are a unique class of materials having exceptionally good temperature resistance, creep and oxidation resistance. Used in many high temperature applications such as turbine engines.
  • Titanium: Pure titanium is melted at 1670 oC and has a low density of 4.51g / cc (40% lighter than steel and 60% heavier than aluminum). Titanium has a high affinity for oxygen: strong deoxidizer. It can catch fire and cause severe damage. Ti is stronger than Al: high strength and low weight. Titanium very useful as a structural metal. Can be used as a biomaterial. Can be used in high temperature components. The limitation of pure Ti is its lower resistance.

Precious metals such as:

  • Gold: Gold has been revered in almost every human culture for as long as civilizations have been able to admire and use the unique properties of this precious metal. Gold is extremely malleable, conducts electricity, does not tarnish, alloys well with other metals, and is easy to work into wires or sheets. Not to mention that gold is unrivaled in its natural brightness and shiny glow. Because of these unique properties, gold makes its way into almost every sphere of modern life in some way, shape, or form. Some uses of gold are for: jewelry, finance and investment, electronics and computers, dentistry and medicine, aerospace, medals and awards
  • Silver: It is used for jewelry and silverware, where appearance is important. Silver is used to make mirrors, as it is the best visible light reflector known, although it fogs over time. It is also used in dental alloys, soldering and brazing alloys, electrical contacts and batteries.
  • Platinum: A shiny, silver-white metal, as resistant to corrosion as gold. Platinum is widely used for jewelry. Its main use, however, is in catalytic converters for cars, trucks, and buses. This represents about 50% of the demand each year. Platinum is very effective in converting vehicle engine emissions into less harmful waste products. Platinum is used in the chemical industry as a catalyst for the production of nitric acid, silicon and benzene. It is also used as a catalyst to improve the efficiency of fuel cells. The electronics industry uses platinum for computer hard drives and thermocouples. Platinum is also used to manufacture fiber optics and LCD screens, turbine blades, spark plugs, pacemakers and dental fillings. Platinum compounds are important chemotherapy drugs used to treat cancer.

Exotic or rare metals such as:

Bismuth: The common component of all low melting point alloys (95-150°C) and low melting groups. It increases volume in solidification, which makes its alloys excellent for casting, since they pick up every detail when expanded in the mold. Beryllium: Beryllium is a newly emerging material that has several unique properties of low density (one third lighter than aluminum), high modulus to density ratio (six times) greater than ultra high strength steels).

High melting point, dimensional stability, excellent thermal conductivity and X-ray transparency. h However, it has serious deficiencies of high cost, low ductility and toxicity. It is not particularly receptive to the alloy. All conventional machining operations, including some non-traditional processes (e.g., EDM and ECM) are possible. However, it must be machined in specially equipped equipment facilities due to its toxic effect

Tungsten: Tungsten is the only refractory metal with good electrical and thermal conductivity, excellent resistance to erosion, low coefficient of expansion and high resistance to high temperature. Although it has low ductility and malleability, can be manufactured in many ways with appropriate procedures. Thomas Edison’s tests with tungsten during the invention of the incandescent lamp were the most important application.

Other uses are inert gas welding electrodes, electron tube filaments, X-ray anodes, and electron tubes.

Classification of Non-Ferrous Metals:

  • Light metals: aluminum, magnesium, titanium, beryllium, etc.
  • Heavy metals: copper, zinc, lead, tin, etc.
  • Refractory metals: tungsten, nickel, molybdenum, chrome, etc.
  • Precious metals: gold, silver, platinum, etc.
  • Ultralight metals: magnesite, dolomite, carnallite, epsomite and olivine
  • Magnesium: shining, white silver; very light, soft and malleable, but not very ductile; it reacts very strongly with oxygen.
  • Pyrotechnics (fireworks), aerospace and automotive industry, and bicycles.

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