Metals Steels Alloys

Introduction

Metals are one of the most versatile of all construction materials. The process of refining metals allows them to be constructed into almost any shape with limitless possibilities. Metals in construction are rarely used in their purest form — pure being metals that have not been alloyed (combined) with other metallic elements. Commercially pure metals are 99% pure minimum. Some of the metals listed below are available as commercially pure and many can be manufactured to be extremely pure, often 99.999% minimum, referred to as “five nines min.”

Alloy

An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain properties of a metal in the resulting material such as electrical conductivity, ductility, opacity, and luster, but may have properties that differ from those of the pure metals, such as increased strength or hardness. This is typically why alloys are used, in order to add desirable qualities to the metal.

• EXAMPLE: Adding Chromium and nickel to steel makes the steel corrosion resistant, or stainless. It is the ability to make alloys that makes metals so versatile.

Smelting

The process of refining material to extract the “pure” metal. Once the base metal is obtained, it usually undergoes further treatment to eliminate any impurities that might affect its use.