Chinese superb metallurgical technology

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Use of metals was a very important event in the historyof mankind，a progress by leaps and bounds in history as well as a marker for the end of the Stone Age and the beginning of the Metal Age.

Bronze was the first metal being used by man in all ancient civilizations，which was followed by iron.Bronze’s status as the first metal to be used for utilitarian purposes is mainly attributable to its low melting point and easy smelting nature.At a heating temperature of 800℃，copper oxide reduces to produce metal copper whose melting point is at 1,038℃. The pottery technology of the ancient time was already able to provided this reduction temperature. In contrast, ferric oxide is unlikely to reduce to iron whose melting point is at 1,537℃.

At the beginning man started with the use of natural copper. For example, the copper content in some 30-piece bronze wares unearthed from the Weiwu site of Gansu province in 1957-1958 accounts for as much as 99%.

Later man developed copper smelting, that is, copper ore is reduced to produce pure element copper through heating.

Pure element copper is comparatively soft with inadequate hardness. In order to produce desired bronze wares, it is necessary to add other kinds of metals. In Europe and West Asia, with abundant arsenic and antimony mines, these two metals were then added to copper to produce copper alloy.

In China, with a small quantity of arsenic and antimony mines but with rich deposits of tin, lead and zinc mines, tin and lead were added to make bronze, and zinc was added to make brass. China was not the earliest country to make · Stone mould for bronze arrowheads, cast early in 16th century B.C. use of copper but its copper smelting technology level was then the highest.This was followed by the successive invention of many casting technologies of mould casting for stone，clay and pottery wares，and casting by paraffin wax process.For instance，casting by paraffin wax process adopted in the Spring and Autumn period as per the latest estimation，which could be the casting of the modern times，remains China’s significant contribution to the world’s casting technology.During the Spring and Autumn& Warring States period，thanks to the invention of technologies of gold and silver smelting，gold gilding and gold plating，bronze wares were then already exquisitely made.In addition，based on their experience，Chinese ancestors summed up the bronze alloy formulas for varied purposes.”Six Complete Formulas”were mentioned in the great works Records of Examination of Craftsmen written in the Spring and Autumn period.They refer to six 9glgg99·Gold-inlaid bronze dou vessel（Warring States period）proportions of copper to tin for production of bronze alloy, the earliest alloy formula ever known in the world.

China’s earliest ever known bronze ware was discovered from the Linjia site of Dongxiang county, Gansu province, dated 3280-2740 B.C. The unearthed 12.5cm-long bronze sword from the site was kept considerably intact, revealing a long history of Chinese bronze wares. Bronze wares enjoyed great development in Western Zhou dynasty with the most representative being the Simuwu rectangular cauldron measuring 1.33 meters inheight,1.10 meters in length and 0.76 meter in width and weighing 875kg, unearthed from the Anyang site of Henan province.

Use of iron wares was much later than that of copper wares, and the first ever known invention of iron smelting technology was made by the Hittite people of Asia Minor in 1400B.C. Harder than bronze, iron application helped buildup great capacity to make use of nature. Besides, iron ore was more widely distributed and more readily available than bronze ore. Consequently iron wares took the place of bronze wares. The earliest known Chinese iron wares were discovered at the Guo State graveyard of later Western Zhou dynasty in Sanmenxia site of Henan province, including a copper-handled iron sword dated early 8th century B.C. The Spring and Autumn & Warring States period entered the Iron Age and greatly promoted social development. Due to highly developed bronze smelting technology, China’s iron smelting technology also took the lead in the world for over 2,000 years in the period from the Spring and Autumn period to the late Ming dynasty. Four pig iron varieties (white, grey, mottle, and malleable) were already being produced early in the period from the Warring States period to Han dynasty, and from Warring States period to Southern and Northern dynasties, various steel smelting technologies were mastered, including carburized, stirred, and briquetted technologies.