Metallurgy history by stages and ages.

The earliest recorded metal employed by humans appears to be gold which can be found free or "native." Small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c. 40,000 BC. Silver, copper, tin and meteoric iron can also be found in native form, allowing a limited amount of metalworking in early cultures. Egyptian weapons made from meteoric iron in about 3000 BC were highly prized as "daggers from heaven."

Certain metals, notably tin, lead and (at a higher temperature) copper, can be recovered from their ores by simply heating the rocks in a fire, a process known as smelting. The first evidence of this extractive metallurgy dates from the 5th and 6th millennium BC and was found in the archaeological sites in Serbia. To date, the earliest evidence of copper smelting is found at the Belovode site, including a copper axe from 5500 BC belonging to the Vinča culture. Other signs of early metals are found from the third millennium BC in places like Portugal, Spain, and Stonehenge (United Kingdom). These first metals were single ones or as found. About on 3500 BC, it was discovered that by combining copper and tin, a superior metal could be made, an alloy called bronze, representing a major technological shift known as the Bronze Age. The extraction of iron from its ore into a workable metal is much more difficult than for copper or tin. The process appears to have been invented by the Hittites in about 1200 BC, beginning the Iron Age.

Historical developments in ferrous metallurgy can be found in a wide variety of past cultures and civilizations. This includes the ancient and medieval kingdoms and empires of the Middle East and Near East, ancient Iran, ancient Egypt, and Anatolia (Turkey), Carthage, the Greeks and Romans of ancient Europe, medieval Europe, ancient and medieval China, ancient and medieval India, ancient and medieval Japan. Many applications, practices, and devices associated or involved in metallurgy were established in ancient China, such as the innovation of the blast furnace, cast iron, hydraulic-powered trip hammers, and double acting piston bellows.

The age of bronze.

The Bronze Age is the period characterized by the systematic and widespread of bronze that, in Europe, stretching from 3500 BC 1200 BC about. Such use may be based on local melting of copper and tin minerals extracted. The technology of bronze is first developed in the Middle East. Bronze is in use in Sumer, at Ur, in around 2800 BC, and in Anatolia shortly afterwards. It appears in the Indus valley in about 2500 BC, and progresses westwards through Europe from about 2000. At much the same time it is found in crude form in China. From about 1500 BC the Shang dynasty produces bronze objects of exceptional brilliance.

The age of iron.

The Iron Age indicates a period of European prehistory characterized by the use of iron metallurgy, especially for the manufacture of weapons and tools, and covers roughly a period from the late second millennium around the first millennium BC. Iron is a metal which is much more difficult to work than copper or tin. It has a melting point too high for primitive furnaces to extract it in pure form from its ore. The best that can be achieved is a cluster of globules of iron mixed with sludgy impurities. This substance can be turned into a useful metal by repeated heating and hammering, until the impurities are literally forced out. The Hittites are the first people to work iron, in Anatolia from about 1500 BC. A few iron objects dating from before 2000 BC have been found (beads, a ring, some blades), but it is not until about 1500 BC that the working of iron is done anywhere on a regular basis. Historical developments in ferrous metallurgy can be found in a wide variety of past cultures and civilizations. This includes the ancient and medieval kingdoms and empires of the Middle East and, ancient Egypt, and Anatolia, Carthage, the Greeks and Romans of ancient Europe, medieval Europe, ancient and medieval China, ancient and medieval India, ancient and medieval Japan, etc. In ancient China before Europeans mastered these crafts (such as the innovation of the blast furnace, cast iron, steel). However, modern research suggests that Roman technology was far more sophisticated than hitherto supposed, especially in mining methods, metal extraction and forging.

Date: 2016-01-03; view: 926