A Glossary of the Metallurgy Terms You Need to Know

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Sep 11

Not long ago we were chatting with a with a young man who was just starting to invest in precious metals. As we were talking, we realized that he thought that an alloy was something that results when two pieces of metal are welded together. That’s incorrect. (See the definition of “alloy” below.) He also thought that the process of annealing means melting a piece of metal. That’s again incorrect. (See the definition of “annealing” below.)

So as a courtesy to the readers of our blog, today will would like to give you the following definitions of the most common metallurgical terms.

Metallurgy: The branch of science and engineering that deals with the properties of metals and their production, physical properties, and applications.
Alloy: A mixture of two or more metals. Alloys are created to enhance the properties of the metals, such as adding strength, corrosion resistance, or durability. The most common are bronze (made of copper and tin) and steel (iron and carbon).
Annealing: A process of heating a metal to a high temperature and then slowly cooling it to relieve internal stresses, improve ductility, and enhance other mechanical properties.
Casting: A manufacturing process in which molten metal is poured into a mold to form a specific shape as it cools and solidifies. This process is used to create various metal objects and components.
Corrosion: The gradual degradation of metal due to chemical reactions with its environment. The most common form of corrosion is rusting, which occurs when a ferrous (iron-containing) metal combines with oxygen. It can weaken and deteriorate the metal over time, leading to structural issues.
Forging: A metalworking process that involves shaping a piece of metal by applying compressive forces using hammers, presses, or other mechanical equipment. The goal is to change the shape of the metal while maintaining or improving its mechanical properties. One example: Plumbers’ wrenches are made of forged steel, which prevents them from deforming under hard use.
Galvanization: A process in which a protective layer of zinc is applied to the surface of steel or iron to prevent corrosion. This is often done by immersing the metal in a bath of molten zinc or by electroplating.
Hardening: A process of heating a metal to a high temperature and then rapidly cooling it (quenching) to increase its hardness and strength.
Tempering: A heat treatment process that follows hardening. It involves reheating the metal to a lower temperature to reduce its hardness and improve its toughness and ductility.
Heat treatments: Heat treatments include many processes, including annealing, hardening, tempering, and quenching. Heat treatments are generally used to alter the properties of a metal by heating and cooling it in a controlled manner.
Smelting: The process of extracting a metal from its ore or another substance by heating and melting it in a furnace. This process is often used to obtain pure metals from their naturally occurring mineral ores.
Tensile strength: A measure of a material's resistance to a pulling (tensile) force. It represents the maximum stress a material can withstand without breaking.
Welding: The process of joining two or more pieces of metal by melting their edges and fusing them together. Various methods, such as arc welding, MIG welding, and TIG welding, are used for different applications.
Yield strength: The amount of stress at which a material begins to deform plastically (permanently) without any further increase in load. It's an important parameter for determining a material's ability to withstand deformation.

These are just a few of the many metallurgical terms. Understanding these terms is essential for professionals working with metals and alloys in various industries, including manufacturing, construction, and engineering.