Metals, in their many forms, played an important role in the development of civilizations. Entire periods of history are named after the common metal being discovered and used during that time. Native metals, occurring naturally in a near-pure form, were likely the first of these elements to be found, collected and used by early man. The Bronze Age began with the discovery that mixing molten copper and tin formed an alloy with unique properties. The strength and durability of bronze made it ideal for replacing stone to fashion tools and weapons. Egyptians of the period were skilled in shaping metals by hammering bronze into sheet metal for tools, armaments and decorations.
The science, engineering and craftmanship required to effectively apply these unique elements continues to improve even today. Three characteristics of metals that make them useful include their conductivity of heat and electricity, their ability to be stretched and their ability to be shaped.
Conductivity
This property describes metals’ ability to efficiently transport heat and electrical energy. Printed circuit boards use small channels of metal that allow the flow of electrical signals between components. The heat generated by some components will damage or destroy them if not removed. Metallic heat sinks with large surface areas are connected to these components to dissipate the heat effectively.
Ductility
Metal’s ability to stretch without breaking enables the manufacture of wire for a variety of uses. A common application is the transport of electrical energy over long distances with lower power losses. High tensile strength metal wires are also used in bundled cables for lifting very heavy loads.
Malleability
This is metal’s ability to be pressed or hammered into flexible sheets of various thicknesses. Closed shapes like boxes or tubes and pipes can be fashioned from sheet metal for transporting fluids of all kinds. Rigid metallic sheets find use in structural components of buildings.
The many forms and types of metals continue to enable a variety of technologies. Advancements in the understanding of their atomic-level properties are revealing new nanotechnological applications in medicine and science.