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Alloys are a fusion of metals or metals and non-metallic elements through melting, mixing, and cooling, with the resulting material offering greater strength or resistance to corrosion. There are several common combinations of alloys; notably, silver and white copper create sterling silver, while gold and silver or palladium produce white gold. Although there are many alloys available, those that are long-lasting and hard-wearing are commonly used in construction. Examples include cast-irons and steels, and alloys of magnesium, aluminum, titanium, nickel, zinc, and copper.
Metals are known for their durability, so it is no surprise they are major materials used in construction. As a solid substance that easily generates electrical and thermal conductivity, metals tend to be extremely sturdy, ductile, and sometimes shiny. In construction, alloys are standardly used for pipework and structural components.
Specific Alloys in Construction
Construction primarily uses the following alloys: titanium, stainless steel, aluminum, copper/copper tubing, lead, and iron. Each alloy has commonly designated use and possesses the strength and durability desired in construction.
Titanium is a lightweight metal that is strong and exceptionally corrosion-resistant. It is often used for air conditioning and heating systems and in piping and roofing.
Stainless steel is widely used in construction, as is galvanized, mild, light gauge, structural and weather steels. Stainless steel is a combination of steel and elements including chromium, nickel, molybdenum, silicon, aluminum, and carbon; galvanized steel is covered in a protective coating of zinc; and weathering steel has a protective top layer of chromium, nickel or copper. Both galvanized and weathering steel can resist corrosion, while stainless steel avoids rusting and weathering. Steel itself is an alloy of iron and carbon, and sometimes other elements; it is known for its ability to withstand high pressure and tension in construction. Steel commonly used for its durability and versatility, but also its comparably low financial cost.
Like titanium, aluminum is also a lightweight, strong alloy with great resistance to corrosion. Aluminum is favorable in construction for its ductile, workable and versatile properties and is utilized for building ceilings, walls, doors, window frames, heating, ventilation, air conditioning (HVAC systems), and spandrels. Due to the flexibility of aluminum, it is used to efficiently, and relatively quickly, build the exteriors of buildings as a wall cladding system. After steel, aluminum is said to be the second most applied metal in construction and can easily and repeatedly be recycled.
Copper is one of the oldest recorded metals used by humans; the reddish-brown material continues to remain popular in construction. Copper is malleable and ductile, with a particularly high thermal and electrical conductivity. The alloy is said to be one of, if not, the most versatile engineering and construction materials on the planet, and is used for electrical wiring, heating, cladding, rainwater systems, roofing, and oil and gas. As a uniquely malleable alloy, copper’s joints can smoothly transform and make pipes and tubes. Not only is copper an efficient building material, its physical properties – namely color and shine – can be aesthetically pleasing, with copper acting not only as a necessary piece of construction but a statement feature in many buildings.
Historically, paint and pipework were both made with substantial amounts of lead. However, the United States banned lead-based paint in 1978, and lead pipework in 1986. Lead is heavy and was outlawed due to its toxicity when absorbed into the human body. The material is a component of soft solder, and primarily employed in roofing, windows, lining for cornices, cladding, tanks, flashing, and gutters.
Lastly, there are two types of iron: cast and wrought iron. Based on each type’s properties, they have different purposes in building and construction. Cast iron is an alloy that contains less than 5% carbon, as well as small amounts of manganese and silicon. It is very brittle, non-malleable and hard, and is melted and poured into shapes or molds, then cools and solidifies. Cast iron is usually applied to large-scale architecture. Wrought iron is softer and more malleable, creating ease in heating, reheating, and reworking the alloy. A unique feature of wrought iron is that it strengthens as it is reworked.
The strength, versatility, and resistance of construction alloys make them ideal for building. Although there are countless alloys, there are frontrunners for construction including titanium, stainless steel, aluminum, copper/copper tubing, lead, and iron. Most of these materials share similar properties or features, but all can be used for different purposes.
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