Perspectives

Why Alloys are Stronger Than Metals

craft jewellery making using alloyAncient civilization started creating alloys in the 3000 BC. People forged items out of brass, an alloy of copper and zinc, and bronze, an alloy of copper and tin. People used other precious metals like gold and silver for jewelry and decorations, and reserved alloys for everyday items because they were cheaper to produce than precious metals.

Above all, people created alloys because they were stronger than pure metals. Materials made from alloys were much harder that they became an advantage during wartime. But how does the combination of two elements strengthen a material?

Varying Atomic Sizes

The secret behind an alloy’s strength lies in its atoms. Pure metal has identical atoms, which are arranged in neat, regular layers making them slide easily over on another. This reduces the pure metal’s strength.

In contrast, an alloy contains atoms in different sizes because it is a mixture of two different elements. It makes it difficult to slide over each other. Thus, an alloy is stronger than a pure metal.

The Strength of an Alloy

Today, people create a variety of alloys, other than bronze and brass. One of the most important ones is steel, which is a combination of iron and carbon. According to SteelCo Buildings, Inc., a steel building company, steel is one of the best construction materials available. It’s durable, cheap, and versatile.

At 260 mega pascals (Mpa), its yield strength, which is the amount of stress a material can handle, is higher than that of other metals like iron (246 Mpa). Other alloys that have a high yield strength are titanium aluminide (800 Mpa), tungsten carbide (up to 1,000 Mpa), and stainless steel (1560 Mpa).

Last year, a team led by Professor Emilia Morosan, a researcher at the Rice University, created a titanium-gold alloy that is about four times harder than pure titanium. A BBC report indicates that the material may have applications in medical implants.

Development of stronger, better alloys isn’t likely going to stop at titanium-gold. Engineers continue to discover the ideal combination of elements to address the needs of people. Whether it’s for everyday use or for complex purposes, alloys will improve lives.

Tags: /