Chapter 3 The Iron Age

Chapter 3 The Iron Age 212 = 4096 years ago => 2094 BC “You should hammer your iron when it is glowing hot” Maxim 262 - Publius Syrus 142 BC At Ancients associated metals with Celestial Objects • • • • • • Sun = Moon = Jupiter = Saturn = Mars = Mercury = Gold Silver Bronze Copper Iron Mercury World history in 2000 BC • The East – The Indus culture is collapsing West – The Shang Dynasty (northern China) is rising – Bronze Casting is well established Rest East – Mesopotamia culture is waning – Start of Assyrian trading colonies in Anatolia (Hittites) • The West – Trade Routes, ceramics, Adena Mounds (c1000 BC) in Ohio • The Rest – Stonehenge being built in England – Egyptians are about done building the Pyramids Assyrians trade with Hittites at Kanesh, Anatolia (Turkey) • Recorded sales on clay tablets show dealings with the Hittites • Had self-fluxing ores near Black Sea – magnetite and olivine • Skilled metal workers in Chalybes tribe (Armenia) • Invasion in 1200 BC destroyed empire but spread the iron-making technology Invasion of the Sea peoples c1200 BC • From direction of today’s Greece - settled in Palestine as the hated Philistines • Destroyed culture, political and trade routes • Ended the Bronze Age (no tin) • Locals switched to iron as best local material – just needed to improve the metal’s properties Iron in The East • The Iron Pillar near Delhi, India – from 4th century AD – Made of wrought iron (sections hammered together) has yet to rust!!! – More data in Chapter 4 • Iron in The West??? – Meteorite in today’s Canadian Arctic had 10,000 Stone Age stone hammers strewn around it. Iron in The Rest • Earliest source = meteorites (iron+nickel) – steel knife in King Tut’s tomb 1339 B.C. • Copper mining by Egyptians at Timna, Israel – Used iron ore as flux for copper smelting • Bloomery iron (mixed with slag) could be hammered into shapes – very weak and rusted quickly More European links to the Iron Age • Hallstatt, Austria – Looking for salt (Roman salary) – using iron from 700-500 BC • They spread the technology across Europe – Spain, France, Denmark Norway, and • the Celts in England – horseshoes, iron rim chariot wheels, plowshare Patina = Surface treatment • Copper => Copper Oxide (green) • Aluminum => Aluminum Oxide (dull) • Zinc => Zinc Oxide (galvanized iron) • Iron=>Iron Oxide=>Iron=>Iron Oxide Wrought Iron is improved through Processing • Hot working iron in carbon atmosphere introduces <1.2% carbon to surface (steeling) – Becomes twice the strength of bronze Wrought Iron is improved through Processing • Hot working iron in carbon atmosphere introduces <1.2% carbon to surface (steeling) – Becomes twice the strength of bronze • Quenching described in Ulysses' Odyssey (800 BC) – harder but more brittle Wrought Iron is improved through Processing • Hot working iron in carbon atmosphere introduces <1.2% carbon to surface (steeling) – Becomes twice the strength of bronze • Quenching described in Odyssey (800 BC) – harder but more brittle • Tempering (brief reheating to 700°C) helps improve Surface properties - reduce breakage – Used today for drill bits, chisels, concrete nails, railroad wheels and even glass Wrought Iron is improved through Processing • Hot working in carbon atmosphere introduces <1.2% carbon to surface (steeling) – Becomes twice the strength of bronze • Quenching described in Odyssey (800 BC) – harder but more brittle • Tempering (brief reheating to 700°C) helps improve Surface properties - reduce breakage – Used for drill bits, chisels, concrete nails, glass, railroad wheels • Annealing (Time & Temperature) - Tempers complete object – Used in metals and glass processing The Fayette connection to Annealing • All glass products must be annealed to relieve internal stresses – Window glass, light bulbs, headlights, TV picture tubes, drinking glasses, beer bottles • 80% of all the glass products in the world are annealed in a furnace built in Fayette County • E.W. Bowman, Uniontown, PA – the world’s leading producer of glass lehrs Makin’ Metals Today Flux Mining Grinding Smelting Separating Slag Usin’ Metals Finished Products Forming Alloys Ingots+Slag Homework: Religions (1) Date the start of each religion, and (2) summarize its view of our relationship with nature. (3) How are metals related? • The East – S=Hinduism+Buddhism, N=Taoism+ Shintoism • The West ?? – S=Aztecs+Incas, N=Norse+Celtic • The Rest – S=Judaism+Christianity, N=Islam+Greek/Roman Transition Vitamin B12 = Cobalt + Cyanide http://www.perl.com/pub/1999/08/onion/talk1.html Recipe for Cornbread • • • • • • • • 1 cup 1 cup 2 Tbsp 4 tsp 1/2 tsp 1 cup 1/4 cup 1 Yellow Cornmeal All purpose flour Sugar Baking Powder Salt Milk Shortening Egg