The first alloys were made sometime during prehistoric times, perhaps soon after people first learned about metals. These alloys were made of metals that were bountiful and easy to melt, i.e. copper, lead, tin, and zinc. Bronze, being the first strong alloy, was probably discovered when copper and tin were smelted together, which enabled them to harden. It was much harder than either copper or tin. Bronze became widely used, particularity for knives, spearheads, and other weapons or tools that needed to be sharp for whatever purpose. There will be three alloys discussed specifically below in which these include: costly and ornamental alloys; alloys of iron; and alloys for strength and lightness.
Costly and Ornamental alloys
Gold and silver have long been used as alloys rather than as pure metals. Just enough cheaper metals are added to them to reduce the cost of gold and silver articles while keeping the appearance of the previous metals satisfactory. Such alloys also can harden the gold and silver thus keep them from wearing through continued and consistent use. Gold is often alloyed with such metals as copper, palladium, platinum, and or silver. For example, yellow gold is an alloy that consists of gold and equal parts of copper and silver. Articles made from alloys of gold include jewellery and ornamental objects. Silver is usually alloyed with copper to make jewellery and table ware. Some cheaper alloys such as German silver, and pewter, are used to make attractive but inexpensive objects.
Alloys of Iron
Iron is the most vital metal, of all the metals used during the industrial revolution. It is almost always used in as alloy rather than as a pure metal. Alloys “that contain iron are ferrous alloys”. [1] Those that do not contain iron are nonferrous alloys. Wrought iron is one of the purest forms of iron in common use today. It contains a minuscule percentage of carbon, which is often present in nearly all types of steel and iron. Wrought iron is tough, but can be rather soft and easily worked. It is often made into a porch railing and other decorative items. Cast iron is comprised of 2-4 percent carbon. Cast iron is very hard and brittle, and cannot be worked at any temperature. Stainless steel contains nickel and chromium. This steel is also noted for its ability to resist rust, tarnish, and the effects of heat and wear. Tungsten steel is a valuable alloy for such metal cutting tools as power saws and drill bits.
Alloys for Strength and Lightness
These material alloys are commonly used in vehicles, aircrafts, where the alloy must be sufficiently strong for safety of the end user, operator, as well be light enough for effective speed. Alloys have been created to satisfy these requirements. Pure aluminum is too light for most construction purposes, thus that is when we mix aluminum with other metals, to make the alloy much harder, durable, and light. One of the first of these alloys was duralumin, which contains mainly aluminum, with small amounts of copper, and magnesium. Duralumin is only slightly heavier than pure aluminum, and often as strong as steel. New alloys of aluminum have been developed containing zinc, magnesium, and lithium. These alloys are even stronger and more resistant to bending than is duralumin.
Source
World Book, Inc. 1994. Volume 1 (A). “Alloy Types”. World Book Encyclopedia. Pg 377.
