An alloy is a homogeneous mixture of two or more metals, or a metal and a non-metal. Alloys are produced by mixing metals in their molten state in specific ratios to form a new material with unique properties. Alloys are known to feature metallic bonding and can be classified into two categories based on the arrangements of atoms in their respective lattices: substitutional alloys and interstitial alloys.

Examples of alloys include:

• Brass: an alloy of copper and zinc.
• Bronze: an alloy of copper and tin.
• Steel: an alloy of iron and carbon.
• Duralumin: an alloy of aluminum, copper, and magnesium.
• Nichrome: an alloy of nickel, chromium, and iron.
• Solder: an alloy of tin and lead.

Alloys are used in a wide variety of industries such as manufacturing, electronics, domestic goods, architecture, plumbing, and the automotive and aerospace industries.