What are examples of common alloys and their compositions?

Common alloys include bronze (copper and tin), brass (copper and zinc), and stainless steel (iron, carbon, and chromium).

Bronze is an alloy primarily composed of copper, with tin as its main additive. It was one of the first alloys created by humans, dating back to around 3500 BC. The addition of tin to copper makes bronze more durable and harder than pure copper, making it ideal for making tools, weapons, and sculptures. The typical proportion of copper to tin in bronze is around 88% copper to 12% tin, although this can vary depending on the desired properties of the alloy.

Brass is another copper-based alloy, but its secondary component is zinc instead of tin. The proportions of copper to zinc can vary widely, but a common ratio is 67% copper to 33% zinc. This alloy is known for its bright gold-like appearance and its acoustic properties, which make it popular for use in musical instruments. It's also highly resistant to tarnishing and corrosion, making it useful in decorative applications and in environments where it may be exposed to the elements.

Stainless steel is an alloy of iron, with carbon and chromium as its main additives. The chromium gives the steel its 'stainless' properties, forming a thin layer of chromium oxide on the surface that prevents the iron from rusting. The carbon is added to increase the hardness and strength of the steel. The typical composition of stainless steel is around 70% iron, 18% chromium, and 8% nickel, with the remaining 4% made up of carbon and other elements. Stainless steel is used in a wide range of applications, from cutlery and kitchen appliances to construction and surgical instruments, due to its strength, durability, and resistance to corrosion.