MATERIALS IN PRACTICE Asst. Prof. Dr. Ayşe KALEMTAŞ Office Hours: Friday, 16:30-17:30 akalemtas@mu.edu.tr, akalemtas@gmail.com Phone: +90 – 252 211 19 17 Metallurgical and Materials Engineering Department Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ OBJECTIVE To provide a basic understanding of glass materials. To understand processing, properties, characterisation and design of these materials. Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ REFERENCES Shackelford, James F., Doremus, Robert H. (Eds.), Ceramic and Glass Materials Structure, Properties and Processing, Springer, 2008. Wolfram Holand, George H. Beall, Glass Ceramic Technology, John Wiley & Sons, 2012. Glass Science, R. H. Doremus, Wiley, 1994. D. W. Richerson, "Modern Ceramic Engineering," Second Edition, Marcel Dekker Inc., 1992. W.D. Kingery, H.K. Bowen, and D.R. Uhlmann, “Introduction To Ceramics”, John Wiley and Sons, 1976. Adalbert Feltz, Amorphous Inorganic Materials and Glasses, Wiley, 1993. Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ ISSUES TO ADDRESS What is glass? Classification of glasses Processing and properties of glasses Typical applications of glasses Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ GLASSES GLASSES … Ceramic Materials … … Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ What Do You Know About Glasses? DEFINITION What is glass? Materials Materialsin inPractice Practice PROPERTIES What are the general properties of glassses? APPLICATIONS What are the main application areas of glassses? Asst. Prof. Dr. Ayşe KALEMTAŞ Well Known Glass Products http://www.wolfard.com Classic Wolfard Oil Lamp Heat resistant glassware (microwave safe) Materials Materialsin inPractice Practice Heat resistant glass lid Tempered Glass Cutting Board Asst. Prof. Dr. Ayşe KALEMTAŞ Well Known Glass Products Tempered glass table http://freshome.com http://www.ifjk.org www.aarticommercial.com/prod ucts.php www.tripadvisor.com Glass sink cabinets in the bathroom Laminated Windscreen Glass Materials Materialsin inPractice Practice Heat resistant glass door Asst. Prof. Dr. Ayşe KALEMTAŞ Well Known Glass Products www.whitersstreetglass.com.au Glass splashbacks http://www.wickedreport.com Hirom Glass Violin is a product of Hario Glass Co. Ltd., Japan. And also, The world’s first hand made glass violin. www.toxel.com Glass Bathtub http://freshome.com Superdurable tempered glass Materials Materialsin inPractice Practice http://worlds-interior-design.blogspot.com Wall-to-wall glass windows Asst. Prof. Dr. Ayşe KALEMTAŞ Well Known Glass Products Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Consumption of Glass Glass Consumers Glass package, 43 % Sheet glass, 30 % Housekeeping, 12 % Electrotechnical needs, 10 % Plant and cunduits, 5 % Three largest consumers Glass packaging, domestic commodities and construction industry Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ GLASSES Four of the major technological achievements in glass which have had the most profound impact on mankind. Glass window – which enables sunlight to come into dwelling unit Lenses – opthamics for improved vision, microscope, telescope optics Light bulb envelope - lighting Semiconducting glasses – for computer memory, solar cell, photocopiers Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Advantages and Limitations of Glasses Advantages Inert Does not corrode Durable Optical transparency Many forming method Many composition Cheap Materials Materialsin inPractice Practice Disadvantages Brittle Breakable Heavy Asst. Prof. Dr. Ayşe KALEMTAŞ History of Glass The word glass is derived from a late-Latin term glaesum, used to refer to a lustrous a transparent material. Another word often used to refer to glassy substances is vitreous, originating from the Latin word vitrum. Luster or shine and in particular its durability when exposed to the elements of nature, were probably the most significant properties of glass recognised by early civilisations. Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ The Beginnings of Glass Technology The earliest written records of glass making are some famous clay tablets, dating from around 650 BC, from the library of Assur-bani-pal, but these are incompletely understood because we have no dictionary to explain the technical terms. Many centuries passed before written accounts of glass making contained any useful insight besides recipes to be followed by rote. The earliest development in glass making of which we have a reasonably documented description seems to be the invention of glass of lead by Ravenscroft around 1673-1676. Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ GLASSES In 1960, glass production is divided into three large groups Glasses Glass for domestic and industrial use Architectural glass Art glass Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ What is Glass? A glass is a solid that possesses no long-range atomic order and which undergoes the glass transformation from solid to supercooled liquid on heating. Crystalline materials have a definite structure, whereas amorphous ones do not, and therefore only rather general statements can be made about a material which, when hot, is ductile but when cold is brittle, and fractures if there is a sudden change of temperature. Amorphous solids Materials Materialsin inPractice Practice No crystal structure No longrange order Resemble “frozen liquids” No melting point, a glass transition temperature Asst. Prof. Dr. Ayşe KALEMTAŞ What is Glass? Glass is a very brittle material Glass is a linear elastic and isotropic material with no plastic behavior at normal temperatures, which can explain its brittle fracture. It follows Hooke’s law. Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ AMORPHOUS versus CRYSTALLINE • Glass has amorphous structure • Crystalline materials have some periodic crystal structure that results in long term order Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Glass Properties General properties of glasses High hardness / brittle Low density compared to high strength Low thermal expansion coefficient Low heat / electrical conductivity High melting point Good chemical resistance / chemically inert Wide range of optical transmission Transparent Translucent Opaque Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Glass from Nature magma fulgurite obsidian Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ History of Glass - 100 000: Obsidian - 5000: Discovery ‘by chance’ of the glass melting (Persia – Mesopotamy) Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ History of Glass -4000: Materials Materialsin inPractice Practice Jewel in molted glass -(Phoenicia) Asst. Prof. Dr. Ayşe KALEMTAŞ History of Glass -1500: Vases and vessels (Egypt) Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ History of Glass - 200: Glass blown with a pipe (Syria) Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ History of Glass -100: “1st glazing”: Casted glass on table (Rome) 76: Pompei From 2nd to 12th : regression of the glass Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ History of Glass Crown method (6th century) Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ History of Glass Cylinder method (12th century) Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Processing of Glass Starting ceramic powders Final product Batching and mixing of raw materials Homogenisation Batch melting Fining Materials Materialsin inPractice Practice Glass is prepared by cooling from a liquid state without crystallization Asst. Prof. Dr. Ayşe KALEMTAŞ ORDINARY GLASS FABRICATION SAND SODA LIME OTHER GLASS Percentage of Ingredients in Glass Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Composition of Some Typical Glasses Typical composition (wt %) of some of the common commercial glasses Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Types of Glasses The main types of glass are: Commercial glass also known as soda-limesilicate glass Lead glass Borosilicate glass Glass fibre Special glasses Layered glass Tempered glass Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Float Glass Annealed glass Annealed (“ordinary”) glass is the end product of the float glass process. It is carefully cooled through the range of temperatures where the glass solidifies so that no residual stresses develop. Float glass is made using a bath of molten tin, where molten glass is floated along the surface. The perfectly flat surface of the tin is transferred to the glass. Advantages Low cost Materials Materialsin inPractice Practice Disadvantages Breaks in sharp pieces Not as strong as tempered glass Size limitations Asst. Prof. Dr. Ayşe KALEMTAŞ Float Glass Fabrication Sand, soda ash, limestone, salt-cake, dolomite are melted at 1600°C Poured into a bath of molten tin at 1100°C Controlled atmosphere Glass settles and is pulled out at 600°C and annealed Washed, cut & stored Molten tin Furnace Materials Materialsin inPractice Practice Float bath Lehr Asst. Prof. Dr. Ayşe KALEMTAŞ Float Glass Float Glass Used For Mirrors In Building Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ LEAD GLASSES LEAD GLASSES are used for high refractive index, easier working and greater density for lamp envelopes, seals, optical glass CRYSTAL GLASS for art and tableware Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ LEAD GLASSES Leaded Stained Glass Windows Materials Materialsin inPractice Practice This type of glass has been mixed with lead-rich materials while molten; lead replaces the calcium content of a typical glass. Lead glass has a long history. The earliest known example with lead oxide additives is a blue glass fragment from Nippur dated to 1400 BC. Leaded stained glass was first used in medieval Europe as a base for colored glass. This glass was used in mosaic tiles, enamels, stained glass painting, and to imitate precious stones. Lead oxide was used to create enamel for vessels and windows because of its lower working temperature. By the 17th century George Ravenscroft produced the first clear lead glass on a large sale. Taking advantage of his merchant class status, Ravenscroft was able to revolutionize the glass trade and shifted England into the leader as a leaded glass innovator. Scotland, especially Glasgow, became the world center for creating leaded glass windows and glassware. Lead glass in your home’s windows will not cause lead poisoning. However, it is still not safe to lick, chew, or eat your leaded glass windows. As long as you adhere to those rules, you will not risk lead poisoning. Asst. Prof. Dr. Ayşe KALEMTAŞ BOROSILICATE GLASSES BOROSILICATE GLASSES lower thermal expansion better thermal shock resistance, improved chemical durability, for such applications as automobile head-lamps, cooking wares and laboratory apparatus Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ BOROSILICATE GLASSES Borosilicate pyrex type colored tubing for glassblowing Pyrex labware is made of borosilicate glass Borosilicates – headlights on cars and Pyrex (heat resistant glass) Borosilicate glass erlenmeyer flasks Materials Materialsin inPractice Practice Pressure resistant circular panes for sight glasses made of thermally toughened borosilicate glass, which are designed to withstand a continuous onesided fluid pressure at temperature up to 280°C Asst. Prof. Dr. Ayşe KALEMTAŞ History of the glass • Laminated glass: 1909 • Tempered glass: 1929 (automotive) Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Laminated Glass 2 sheets of glass are bonded with a thin film of plastic such as polyvinyl butyrate under pressure at a temperature of about 100°C Laminated glass is a kind of safety glass which is combined from one or more layers of PVB through heating and pressing processes by autoclave. The sandwiched plastic bonds well to the 2 glass surfaces and helps absorb energy in impacts, stops glass shattering and disintegrating if stressed to failure so that it often remains secure and weatherproof. This provides a high degree of resistance to injury from flying glass in case of impact. Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Laminated Glass Laminated glass absorbs energy of the impact Safety • Ordinary window glass is brittle and breaks into long sharp pieces Will not shatter Holds up against • hurricanes • cyclones • earthquakes Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Laminated Glass Laminated glass is widely used for bullet proof burglar-proof showcase counter aquarium skylight long corridor sidelite, etc. Materials Materialsin inPractice Practice http://www.livingetc.com Glass staircase www.aarticommercial.com Laminated Windscreen Glass If the laminated glass is made from “ordinary” float glass, it is still workable (cutting and drilling is possible) and the PVB helps the fractured glass to stay put inside the construction. Asst. Prof. Dr. Ayşe KALEMTAŞ Laminated Glass BULLETPROOF GLASS Bulletproof glass is made of laminated glasses and films which have special shielding capability towards bullets. The different levels of bullet proof glasses are able to shield the bullets from penetration and prevent the broken parts from injuring people. They are widely applied in bank, counters of jewelry and gold shops, cash trucks and other regions requiring special safety prevention. Materials Materialsin inPractice Practice www.bmw-security-vehicles.com 22-millimetre glass/plastic laminate with a polycarbonate coating on the inside to prevent flying splinters. The 22-millimetre glass protects against: • Blunt instruments .44 Magnum with full-jacket flat-nose bullets .357 Magnum with coned bullets 9-millimetre Luger with round-nose bullets Asst. Prof. Dr. Ayşe KALEMTAŞ Tempered Glass Shatter pattern of tempered glass Crazed fracture pattern on left in tempered glass on an elevator wall. Fracture origin is shown above. Materials Materialsin inPractice Practice Tempered glass also know as toughened glass is made by quickly cooling the annealed glass when it is heated near compression is formed over the glass surface whiletensile formed inside the glass plate. Tempered glass is made by heating annealed glass to approximately 700C then cooling the outer surfaces rapidly. This process makes the glass very strong and shock resistant thus more durable. Asst. Prof. Dr. Ayşe KALEMTAŞ Tempered Glass Usage Range of Tempered Glass: Construction curtain wall Glass doors & windows Support bar of staircases & escalators Different types of the glass artdecorations Location of near the intense heatthe impact severed by the hotcold. Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ General Characteristics of Glasses Materials Materialsin inPractice Practice Short range atomic order but no long-range order Structure is isotropic, so the properties are uniform in all directions Typically good electrical and thermal insulators Soften before melting, so they can be formed easily by various forming techniques Asst. Prof. Dr. Ayşe KALEMTAŞ THE END Thanks for your kind attention Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ Any Questions Materials Materialsin inPractice Practice Asst. Prof. Dr. Ayşe KALEMTAŞ
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