2020 – 14 – Summary
A metal’s structure determines its characteristics. When you know about the structure of a metal, you can determine if you have the right metal for your job.
Every atom has electrons that revolve around a nucleus. The nucleus has neutrons and protons. Atoms are also made up of valence electrons, which determine how bonds are arranged. Each element has a unique atomic number which identifies the amount of protons in the nucleus.
When atoms combine, ionic, covalent, or metallic bonds attach them. Bonds tend to form when an atom attempts to fill its outer shell with electrons.
The metals used in manufacturing tend to form one of three crystal structures: Hexagonal close-packed (HCP), body-centered cubic (BCC), and face-centered cubic (FCC) structures. FCC metals are soft and workable but not particularly strong. HCP metals are brittle, and BCC metals are hard and not very ductile. It’s also important to note that as molten metal cools, crystal structures, called grains, form. These grains influence the strength of the metal. A smaller grain structure is stronger opposed to the larger grain structures.