Historical Use of Materials • Through out the history of man, those countries that produced metals of exception quality became wealthy lands. For example, Britain learned to produce a high-quality steel that enable it to conquer 1/5 of the world. • Often a country was invaded because of the metal ores that were know to exist there. For example, Rome invaded England for its Tin mines. • Kings spent fortunes trying to find the secret of the Philosopher’s stone where Lead could be turned into Gold with the transmutation agent being able to right bodily imperfections, cure all illnesses and confer long life. • For a long time, mercury (Hg) was thought to be this agent. • For most of man’s history, every generation went to war, every generation suffered some lose of their kindred. • Types of people and countries exist today because their ancestors kept up with the pace of producing new materials for defense. • Let us look briefly at the ages of man through the looking glass of its metals.
Historical Use of Materials • Stone Age • ~500,000 yrs ago, early man used flint, bones and stones • ~100,000 yrs ago, Piltdown man used stone for knives, axes, and borers • this period ended ~6000 yrs ago but continues in some restricted places still today (S. America, Africa and Indonesia) • Metal Age • the real history of metals and man starts ~35,000 yrs ago when homo sapiens displaced Neanderthals • gold was first to be discovered and used for ornaments. • iron from meteorites was used for tools. • even though iron was the first “really hard” material to be used, it took the longest to be produced by man into useful tools. Learning how to produce iron or steel still continues today. • today 90% of man-made material is iron-based.
Historical Use of Materials • Copper Age • weapons were made of stone – before the great flood of 4,000 BC • weapons were made of copper – after the great flood of 4,000 BC • Copper was 1st made from its ore in the Persian Gulf at the Tigris and Euphrates in a land called Ur • Copper being cast into shapes occurred ~3500 BC in Egypt and India • Bronze Age • ~1,200 BC, probably by accident, Bronze was produced from mixing Copper (Cu) with Tin (Sn) when Cu was made from CuO ore in SnO2 hearths. • bronze is much stronger and harder than Cu. • the use of Bronze quickly spread throughout Europe as far as the Baltic, to India and then to China. • development can be followed by the axes and swords produced. • even today, places in India, and its surrounding countries, still produce the finest quality of Bronze.
Historical Use of Materials • Lead • There was no Lead Age but it played a significant role in the history of man. • Lead, being easily shaped, was used for water ducts and eating utensils and plates afforded by the rich. • Lead poisoning creates confusion and the inability to make rational decisions, which caused the Fall of Rome (700 AD). • Brass • There was no Brass Age but it played a significant role in the history of man. • Brass was produced from Copper and Zinc oxide. • Brass having 21-28% Zn was used for coins that didn’t corrode, establishing our currency system of trading. • Other metals corroded and there was too little gold. • Rome conquered Spain just to get control of its Cu and Zn mines. • Concrete • There was no Concrete Age but it played a significant role in the history of man. • The Romans invented concrete who used it for their buildings, which still stand today, and their roads. • Rome’s army was kept fit by building roads during quiet periods, establishing trade routes that still exist today. Roman built roads are still in use today!
Historical Use of Materials • Iron Age • The use of Iron very slowly replaced that of Bronze. • It first started to be produced and used in the Middle East by the Hittites in Ur. • The Hitites were feared by Egypt, which destroyed them in 1,200 BC slowing the development of iron. • ~400 BC, the Greeks (and later Romans) learned that water quenched and tempered iron was much harder, stronger and less brittle than forged iron. • The Romans defeated the Gauls because the Gauls had to straighten their softer and weaker weapons after taking the first thrust on their spears and armor. • Even up to the 17th and 18th century, there was no clear pathway for metallurgists to proceed to produce better, higher quality metals, including iron, relying instead of the Greek philosophies earth, wind, fire and ice. • The Arabs lead the way between the 700 AD and 1200 AD by producing furnaces, referred to as the Philosophers egg or Vase of Hermes, that produced higher temperatures and thus purer metals. These evolved into Blast Furnaces, which from iron ore and charred wood (charcoal) eventually produced wrought iron (forged at high temperatures) and cast iron (poured into a mold).
Historical Use of Materials • Iron Age (cont’d) • A low quality steel, called blister steel, which used a primitive carburizing technique that formed blisters on it surface, was produced in Egypt in the 1300s but came to an end due to the Black Death that ravaged the known world. • In the 1400’s metallurgists remelted cast iron and refined it by removing impurities, known as “refining”, which produced a steel that was more malleable. • Methods to refine continued to improve steel into the 1700’s such that it replaced Bronze and Brass to make cannons, as well as, for making cannon balls, which up to that time were made of stone so their shots became accurate. • Wrought iron guns (rifles) also started to be made, which shot lead balls made in shot towers located in every city and village, usually in their centers. • England, Germany and Scandinavia also began producing iron during the middle ages by medieval metallurgists as they had plenty of iron ore and forests, preferably hard wood, for charcoal. • So much hardwood was being cut down in England that it was banned by its Parliament so England started to import iron from European (mostly Swedish who made 1/3 of world production) Iron Mongers. Iron was then restricted for import by Parliment.
Historical Use of Materials • Iron Age (cont’d) • This restriction severely affected the production of Caxton’s press for making newspapers and books. • Three books on steel making were published around this time: • The Pirotechnia by Vannoccino Biringuccio • De Re Metallica by Georgius Agricola • Autobiography by Benvenuto Cellini (a metallurgist) • These became the metallurgists bibles and were used by many to start iron works. • Making Iron in America was first attempted in Jamestown, Virginia but failed. • In 1644 an iron plant was established in Hammersmith, Massachusettes. • Eventually, the Americans produced so much that they would sell iron to England as it had large forest with no charcoal restrictions. • Eventually, in the 1700s coal, and shortly thereafter coke, began to be used for iron making in England, which over came the shortage of charcoal and brought new life to its industry. • During the next 100 years, Britain was the greatest iron producer in the world and lead the world for ~300 years making its industry and Kingdom thrive.
Historical Use of Materials • Steel Age • Slowly the Iron age turned into the Steel Age as impurities were removed from the iron and Iron Alloys began being produced. • The steel age, which some would argue is still continuing today, has had a major impact on modern man (ships, buildings, cars, etc. etc. etc.). • As Iron furnaces improved, the quality or purity of Iron turned it into Steel, which is an Iron-Carbon alloy. • The first “Steel” is considered to be Wootz steel made in India ~500 BC using a type of blast furnace using clay pots but it wasn’t very reproducible. • Damascus steel involved fusing together layers of steel and iron by hammering to form a type of composite, which was stronger than other steels of its time. • Later the Damascus method was refined by the Japanese who took it to a much higher level for their samurai swords. • Similar to Wootz steel, Benjamin Huntsman used a crucible process in 1740 to produce the first steel that was sufficiently reliable to be accepted and used in many parts of the world. • This steel enabled the Industrial Revolution to occur in Western Europe. • Crucible steel making reached an all-time high in the United States, which took the lead from Britain in 1890.
Historical Use of Materials • Steel Age • An English inventor, Henry Bessemer in 1854 applied for a patent for “Improvements in the Manufacture of Iron and Steel”, which involved decarburizing the molten steel by blowing air over it using a fireclay pipe such that the iron because free of carbon (0.1% to 1.5% C) and other impurities. • In his method, the heat generated by the oxidation process was sufficient to keep the iron molten, when, in fact, to Bessemer’s surprise it became hotter. • Stopping the blow at a good carbon content was still a problem called hot-shortness that brittled the steel so it could not be forged when hot. • Hot shortness was solved by blowing all the carbon out and then adding a small amount of spiegelsen (a type of pig iron containing 15-30 % Manganese and 4-7% C) where Mn helped the steel become malleable. • the Bessemer process reduced the price of steel sufficiently that it could be used in large quantities such as rails and girders for the railway industry and plates for battleships. • In 1885, the British government accepted Bessemer steel for its guns and naval shipbuilding. Why?
Historical Use of Materials • Steel Age • Another inventor, Charles Siemens, a German who settled in England in 1844 modified a reverberatory furnace that developed into the Open Hearth method of steel making which became the most popular method during the 1900s. • A reverberatory furnace used the flames of gas burners put over the steel melt or hearth to heat the steel along with the heat reflected from the furnace roof. • As well, instead of the hot burned gases going up a chimney, they were redirected through brickwork chambers to preheat incoming air and gas, which enabled a higher temperature of steel to be produced. • This method was also used for glass making, which needs to reach ~2000 oC. • So much heat was produced that very large charges could be made that included steel scrap, which substantially reduced its cost. • High-quality steel can be produced as there is time for measuring its impurity content and alloy levels. • the Open Hearth method dominated steel making right up into the 1980s, however, • It is being replaced these days as it takes too long, sometimes longer than a week, for one charge to finish.
Historical Use of Materials • Steel Age • Bessemer steel makers became aware of two deficiencies of the process; the inevitable nitrogen pick-up in the steel from the air blast and the difficulty in judging the end of the after-blow (final C removal). • Bauxite, an aluminum ore, can be used to remove the impurities but it adds too much to the cost. • These problems were solved by blowing pure oxygen into the steel bath using a lance inserted from the top of the vessel in a way that Bessemer described in a patent in 1855 but he was never able to realize because of the high heat. • The Basic Oxygen Furnace (BOF) was first developed in Austria and called the Linz-Donawitz process. A water cooled lance is used for a short time. • In 1953, Dofasco in Hamilton Canada secured the exclusive rights to the basic oxygen furnace technology from the Austrians and with the expertise of engineer immigrants from Austria, German and the UK, was able to pioneer many of the important developments of the basic oxygen steelmaking process such that by the 1970’s the BOF started to dominate steel production in North American. • Dofasco took over Stelco as Canada’s largest steel maker in the 1990s and provides much of the steel used in cars and buildings today. • The BOF can make a charge of steel in 20 minutes and over the decades has become the common standard for steelmaking around the globe.
Historical Use of Materials • Canada • Apart from iron ore, which was mined prior to the British conquest of Canada in 1763, minerals do not play an important part in Canada’s economic history until the late 1800s. • Mining really started in Sudbury, Ontario, where large copper and nickel deposits were found during the construction of the Canadian Pacific Railway in 1883, which originated from a large meteor hitting the earth enabling Nickel to be produced at 50% of the world’s production today and at times 90%. • Mining pulled Canada out of being essentially a farming, trapping, and fishing community during the 1900s. • Ontario also been producing cobalt, silver, gold and more recently diamonds. • Quebec produces copper and for a period, asbestos, which was used for insulation but found to be carcenogenic so has mostly discontinued. • Manitoba produces Zinc. • British Columbia produces copper, lead and zinc, along with other high value materials such as antimony, indium, gallium and arsenic. • Huge iron ore and coal deposits have been found in Labrador that are semi-processed into pellets and shipped to Hamilton for use by the Steel Industry. • Canada is currently the world’s supplier of uranium from its northlands, which will become increasingly valuable as we try to reduce global warming.
Periodic Table How did we determine the presence of all the elements of the Periodic Table? • Before the 1900s, very few elements were known, which included gold, silver, lead, tin, zinc, copper, iron and antimony (reduced from antimony sulphide). • X-ray were discovered in 1895 by RÖntgen, which fluoresce from materials when they are irradiated by high energy x-rays, electrons or ion beams. • The energy of the x-ray fluorescence could be used to determine the elements present (electronic structure) and, eventually, their composition. By this means, missing elements from the periodic table could be found and even created by man. • The invention of the Period Table is attributed to Dmitri Mendeleev in 1869 who intended to illustrate recurring trends in the properties of the elements. • Its layout has been refined and extended over the years as new elements have been discovered and new models have been developed to explain chemical behaviour. • So far, 117 elements have been discovered.
From Alchemy to Metallurgy During the 1600s/1700s, the people developing materials gradually started to understand some of the whys and ways of the techniques they were using. • If one had to state categorically whose work this gradual enlightenment depended upon, it would be Robert Boyle, a seventeenth century chemist who made a distinction between elements, compounds and mixtures and laid the foundations for modern chemistry, clearing away the decaying alchemical philosophy that outlived its usefulness. • In 1722, another book was published entitled, “Memoirs on Steel and Iron” by Rene Réaumur that included practical theories on processes such as malleabilizing cast iron and heat treating steels. • Surface polishing techniques were developed in 1863 by Sorby by using successively finer abrasives to produce a mirror-like finish, which enabled grains to be seen using an optical microscope. • RÖntgen’s x-rays were used by William Bragg to determine a material’s crystal structures that determines much of its mechanical and other physical properties. • The first electron microscope, as we know it, was built in 1938 by the Canadians; Cecil Hall, James Hillier and Albert Prebus, at the University of Toronto. This type of microscope can now see smaller than an atom and ~1,000,000x less than an optical microscope. It has enabled, and will continue to enable, development of advance materials that previously were only seen in sci-fi movies.
Compositional Analysis The quality of any material is largely dependent on its impurity concentration. The following methods are used to determine the presence and concentration of impurities and alloying additions. • Gas Flame spectroscopy – a small sample of material is burned in a flame and the flame’s colour and its intensity is used to determine the material’s composition. It is fast and effectively used during the making of steels and other materials. Can measure fraction of 1% composition. • Mass spectroscopy – a small amount of material is dissolved in an acidic solution, which is vaporized by heating. The vapor is injected into a tube with a carrier gas where the light elements travel quickly and the heavy elements travel slowly through the tube. At a meter or so from the beginning magnetic induction measures changes in the gas due to the elements. Time and degree of change in inductance determine the elements present and their composition. Can measure parts per million.
Compositional Analysis • SIMS (Secondary Ion Mass Spectrometry) – An ion beam is fired at a material sample, which loses surface atoms (now ions) by sputtering, which are collected and analyzed by a mass spectrometer. It is the most sensitive technique for elemental, isotopic or molecular composition being able to detect elements present in the parts be billion range. • X-ray spectroscopy – High energy electrons from an electron microscope impinge a material sample causing x-ray fluorescence of the k, l, and m shells of electrons, which are detected using an energy dispersive spectrometer that can determine the composition of the material to a fraction of 1%. Its advantage is the small volume of material that can be analyzed (~1 nm3) • Electron Energy Loss Spectroscopy - High energy electrons from an electron microscope pass through a material sample losing energy to the atom’s electronic structure. It can determine the composition of a small volume of material to a fraction of 1%.