MTPDF8 Engineering Materials and Metals and Polymers.pdf

Chemistry for Engineers 2 ENGINEERING MATERIALS, METALS AND POLYMERS MPS Department | FEU Institute of Technology  OBJECTIVES ▪ To describe basic concepts of crystal structure. ▪ To define mechanical properties. ▪ To define common engineering mate...

Chemistry for Engineers 2 ENGINEERING MATERIALS, METALS AND POLYMERS MPS Department | FEU Institute of Technology  OBJECTIVES ▪ To describe basic concepts of crystal structure. ▪ To define mechanical properties. ▪ To define common engineering materials and their properties. ▪ To identify the types and uses of nanomaterials.  INTRODUCTION TO ENGINEERING MATERIALS  OBJECTIVES ▪ Define common engineering materials ▪ Describe basic concepts of crystal structure; Engineering Materials refers to selecting the correct materials for the application in which the engineered part is being used. This selection process includes choosing the material, paying attention to its specific type or grade based on the required properties. https://images.app.goo.gl/8pjBaxeMohsLh4PC6  CRYSTALLINE are solids in which atoms are arranged in an orderly repeating pattern. They usually have flat surface, or faces, that make definite angles with one another. https://images.app.goo.gl/WntSSy8rg1A2FfnQ9  AMORPHOUS solids in which atoms are not arranged in an orderly pattern. At the atomic level, the structures of amorphous solids are similar to the structures of liquids but they lack the freedom of motion similar to liquids. https://images.app.goo.gl/fWaTrBZPDpxETsr29 Unit cells are relatively small repeating unit in a crystalline solid They are made up of a unique arrangement of atoms and embodies the structure of the solid. These unit cells are stacked in three dimension, thus determining the following attributes of the unit cell: a. Size and Shape of the unit cell b. Location of atoms within the unit cell https://images.app.goo.gl/QeKjSqtEgs4DtjJbA The geometrical pattern of points on which the unit cells are arranged. The crystal lattice is, in effect, an abstract scaffolding for the crystal structure. https://images.app.goo.gl/QeKjSqtEgs4DtjJbA https://images.app.goo.gl/YkMXAPJ8gVavxHBn8 Simple Cubic Body Centered Face Centered (Primitive) Cubic (BCC) Cubic (FCC) https://images.app.goo.gl/gWUn7NuaDNG8vSuSA An infinite array of discrete points with an arrangement and orientation that appears exactly the same In 1850, M.A. Bravais showed that identical points can be arranged spatially to produce 14 types of regular patterns. https://images.app.goo.gl/h3reUo3HQHV7hxQa8 Solids that are held together by a delocalized sea of collectively shared valence electrons. This form of arrangement allows metals to conduct electricity and is also responsible for metals being strong without being brittle. https://images.app.goo.gl/RXepE2oybf7sYcfL9  Do not hold the characteristics of metals Many materials like coal and Sulphur are very soft and dull in appearance. They break down into very fine thin powdery mass on tapping with the hammer. They are neither sonorous and also are a very poor conductor of heat and electricity. Few examples of non – metals are carbon, https://images.app.goo.gl/R9whZqSwPrwv4skTA oxygen, Sulphur, etc. POLYMERS are materials that has a molecular structure consisting chiefly or entirely of a large number of similar units bonded together. Examples: many synthetic organic materials used as plastics and resins. https://images.app.goo.gl/FaewKBYLcZApK4EU9  Inorganic and nonmetallic materials like tile, bricks, plates, glass, and toilets. They have excellent strength and hardness properties. They are typically brittle in nature. Mixtures of clay, earthen elements, powders, and water and shaping them into desired forms and then fired in a high https://images.app.goo.gl/uFSNQW6cYyhR5gXN7 temperature oven called a kiln. Thin materials produced by pressing together moist fibers of cellulose pulp derived from wood, rags, or grasses, and drying them into flexible sheets. It is a versatile material used in many ways like writing, printing, packaging, cleaning, decorating, and a number of industrial and construction processes. https://images.app.goo.gl/BFTFgcuxFv4tyRJv8 MECHANICAL PROPERTIES OF MATERIALS  OBJECTIVES ▪ To define mechanical properties of materials Describes the behavior of material in terms of deformation and resistance to deformation under specific mechanical loading condition. Hardness, Strength, Toughness, Brittleness, Elasticity, Plasticity, Ductility, Malleability  HARDNESS STRENGTH is the resistance to permanent is the property that enables a indention, scratching, and wear. material to resist deformation under load. https://images.app.goo.gl/eWvfxi4gN8WRMYnv6 https://images.app.goo.gl/baCwQ1br6SNQTTh6A  ELASTICITY PLASTICITY is the ability of a material to is the ability of a material to return to its original shape after deform permanently without the load is removed. breaking or rupturing. https://images.app.goo.gl/x2j8eKUjv6nmxtm68 https://images.app.goo.gl/dVUXa5X3vp1hgqA87  TOUGHNESS BRITTLENESS is the property that enables a is the opposite of the property of material to withstand shock and plasticity. A brittle metal is one to be deformed without rupturing. that breaks or shatters before it Toughness may be considered as a deforms. combination of strength and plasticity.  DUCTILITY MALLEABILITY is the ability of the material to stretch is the property that enables a material when applied with stress. This is usually to deform by compressive forces a metallic property. It is ability of the without developing defects. A malleable material to deform easily upon the material is one that can be stamped, application of a tensile force, or as the hammered, forged, pressed, or rolled ability of the material to withstand into thin sheets. plastic deformation without rupture.  ENGINEERED NANOMATERIALS  OBJECTIVES ▪ To identify the types and uses of nanomaterials Nanomaterials are objects that are sized between 1 to 100 nanometers. Materials engineered to such a small scale are often referred to as engineered nanomaterials (ENMs), which can take on unique optical, magnetic, electrical, and other properties https://images.app.goo.gl/BZ3ECLjN1t7FD1Lq8 These nanomaterials are composed mostly of carbon, most commonly taking the form of a hollow spheres, ellipsoids, or tubes. https://images.app.goo.gl/dkj8h76qs6B2Qpmm9  FULLERENES carbon based nanomaterials that are spherical and ellipsoidal in shape. https://images.app.goo.gl/r4pmmjKKQ8isBjWw9  NANOTUBES carbon based nanomaterials that are cylindrical in shape. https://images.app.goo.gl/Qy54hyzkSRBHjAtR8 These nanomaterials include quantum dots, nanogold, nanosilver, and metal oxides, such as titanium dioxide https://images.app.goo.gl/ifiG6gsdYsW1Bapt9  QUANTUM DOT a closely packed semiconductor crystal comprised of hundreds or thousands of atoms, and whose size is on the order of a few nanometers to a few hundred nanometers. https://images.app.goo.gl/xfLAk8W2Baf9ktaM6 These nanomaterials are nanosized polymers built from branched units. The surface of a dendrimer has numerous chain ends, which can be tailored to perform specific chemical functions. https://images.app.goo.gl/JszLvYzeK9eUBtbb6 They combine nanoparticles with other nanoparticles or with larger, bulk-type materials. Nanoparticles, such as nanosized clays, are already being added to products ranging from auto parts to packaging materials, to enhance mechanical, thermal, barrier, and flame-retardant https://images.app.goo.gl/PuweJwqdJLBAdpuD9 properties. CATALYSIS One application is the use of Cerium (IV) oxide nanoparticles which are added to diesel and bio-diesel fuels in very small amounts (5-10 ppm) to facilitate complete combustion POLYMERS AND GLASS Carbon nanotubes are used in polymers and composites to strengthen a structure, to increase the electrical conductivity of the material and to increase heat transfer. TEXTILE AND FABRIC Nanomaterials can be used in these products to provide properties, including anti-bacterial, anti- fungal, deodorizing, thermal-regulating and static- free, yet soft and comfortable to wear. The nanoparticles are embedded in the fibers rather than present as a coating, and are not removed from the fabric when washed. https://images.app.goo.gl/WpYRyvZcgbosi4Tr7 HEALTHCARE Biological micro-electromechanical devices (bioMEMS) implanted into the body to deliver doses of drugs. Gold nanoparticles are also use to locate the site of cancer cells and can be irradiated with infrared to heat them up and destroy the nearby cancer cells. https://images.app.goo.gl/DcMGtQJ2UwYiZmXt7 METALS AND POLYMERS  OBJECTIVES ▪ To describe the properties of metal, ▪ To discuss different types of alloys, ▪ To define polymers, its structure and types. METALS  OBJECTIVES ▪ To describe the properties of metal; ▪ To discuss different types of alloys Metals are materials that has characteristics like ✓ high electrical and thermal conductivity, ✓ ability to be deformed or cut into new shapes without breaking, ✓ and high mechanical strength. Generally, ✓ They are often vulnerable to corrosion damage as the metals react with their environment to re-form those compounds. ✓ They tend to be shiny and malleable. ✓ Metals have these characteristics because they have non-localized electrons. https://images.app.goo.gl/b3FHx3vZ9AdTeKk78  SOLID AT ROOM TEMPERATURE EXCEPT: ▪ Mercury is the only metal that is liquid at room temperature ▪ Gallium is liquid at hot temperature https://images.app.goo.gl/xvTjGctQgAfr15hR8  LUSTER Quality of reflecting light from their surface can be polished Examples: gold, silver and copper. https://images.app.goo.gl/vKgEvNZH1yXh1TfP6  MALLEABILITY Ability to withstand hammering and can be made into thin sheets known as foils. EXAMPLE: a sugar cube sized chunk of gold can be pounded into a thin sheet that will cover a https://images.app.goo.gl/G4gUBqdzyXTAWsGs8 football field.  DUCTILITY Can be drawn into wires EXAMPLE: 100 g of silver can be drawn into a thin wire about 200 meters long https://images.app.goo.gl/M9dCM6nAZ52JobCJ8  HARDNESS All metals are hard EXCEPT: sodium and potassium, which are soft and can be cut with a knife https://images.app.goo.gl/fSMboyC5TbzEP1Hx5  VALENCY Metals typically have 1 to 3 electrons in the outermost shell of their atoms. https://images.app.goo.gl/iCo3jigcrrSJrVL6A  HIGH MELTING AND BOILING POINTS Highest MP/BP: Tungsten Lowest MP/BP: Mercury Sodium and potassium have low melting points. https://images.app.goo.gl/tfbNQH6zJgQ3Tbsm7  CONDUCTIVITY Good conductors because they have free electrons Best conductor of heat and electricity: Silver and copper Poorest conductor: Lead Bismuth, mercury and iron are also poor conductors. https://images.app.goo.gl/LHQpEuZpqW9fpbAL9  ALKALI METALS ✓ very reactive ✓ low melting points ✓ soft enough to be cut with a knife ✓ Include: Lithium, Sodium, Potassium, Rubidium, Cesium, Francium https://images.app.goo.gl/e721HRooeEUfgruC7  ALKALINE EARTH METALS ✓ Found in compounds with many different minerals ✓ Less reactive than alkali metals ✓ Harder ✓ Higher melting points ✓ Include: Berylium, Magnesium, Calcium, Strontium, Barium, Radium https://images.app.goo.gl/exZ6KUxohUFTgreA8  TRANSITION METALS They are what we usually think of when we think of metals. ✓ Hard and shiny, strong, and easy to shape ✓ Used for many industrial purposes. https://images.app.goo.gl/9d1GVmQSY26fmaaS9 The process by which metals are extracted from ores and are modified for their use. It is domain of metallic elements physical and chemical behavior and a whole, it is technology of metals that is https://images.app.goo.gl/tfbNQH6zJgQ3Tbsm7 applied to practical use. Ores are rocks or minerals from which a valuable substance – usually metal – can be extracted. https://images.app.goo.gl/yNYVrq72XZwzBKft5 Some common ores include: Galena (lead ore) Bornite and Malachite (copper) Cinnabar (mercury) Bauxite (aluminum) Most common iron ores are magnetite and https://images.app.goo.gl/yNYVrq72XZwzBKft5 hematite (a rusty-colored mineral formed by 70% iron and oxygen) Or HEAT TREATMENT Involves all of the controlled heating and cooling operations performed on a material in the solid state for the purpose of altering its microstructure and/or properties. https://images.app.goo.gl/vP1rQVK43exrzEV26  ANNEALING QUENCHING a softening process in which rapid cooling of a hot material. metals are heated and then allowed to cool slowly. The medium used to quench the material can vary from forced air, oil, water and others. Purpose: to reduce hardness and increase ductility Quenching results in a metal that is very hard but also brittle. Metals where the properties of different metals are combined by mixing two or more of them together https://images.app.goo.gl/Df6nJHWbTNGJXSKN9 SUBSTITUTIONAL ALLOYS happens when solute atoms in a solid solution occupy positions normally occupied by a solvent atom. https://images.app.goo.gl/9pM8RZivrHoNGkQw9 INTERSTITIAL ALLOYS happens when solute atoms occupy interstitial positions in the “holes” between solvent atoms. https://images.app.goo.gl/9pM8RZivrHoNGkQw9 BASE METAL OR MAIN METAL the most important metallic component of an alloy (often representing 90 percent or more of the material) ALLOYING AGENTS can be either metals or nonmetals and they're present in much smaller quantities (sometimes less than 1 percent of the total) https://images.app.goo.gl/jgsuC2pGoW8ANdtAA  SOLID SOLUTION POWDER METALLURGY The traditional way of making An alternative way of making an alloys which heats and melts the alloy is to turn the components components to make liquids, into powders, mix them together, mixing them together, and then and then fuse them with a allowing them to cool into this combination of high pressure and solution. high temperature.  Name Components Uses BRONZE Cu (78-95%), Mn, P, Al, S Decorative statues, musical instruments BRASS Cu (65-90%), Zn (10-35%) Door locks and bolts, musical instruments, central heating pipes CAST IRON Fe (96-98%), C (2-4%), S Bridges, heavy duty cookwares STEEL (general) Fe (80-98%), C (0.2-2%), other metals Metal structures, car and airplane such as Cr, Mn, Va parts, etc STEEL (stainless) Fe (50%+), Cr (10-30%), smaller Jewelery, medical tools, tableware amounts of C, Ni, Mn, and other metals STERLING SILVER Ag (92.5%), Cu(7.5%) Cutlery, jewelry, medical tools WHITE GOLD (18 carat) Au (75%), Palladium (17%), Ag (4%), Jewelry Cu (4%) POLYMERS  OBJECTIVES ▪ To define polymers, its structure, properties, and types. Polymers are any of a class of natural or synthetic substances composed of very large molecules, called macromolecules, that are multiples of simpler chemical units called monomers. https://images.app.goo.gl/cVQmXmLftNeWj4vo7 Polymers make up many of the materials in living organisms, including, for example, proteins, cellulose, and nucleic acids. https://images.app.goo.gl/4c2R8E2KimUho7x39 Jons Jakob Berzelius coined the word polymer (polys – many, meros – parts) To denote molecular substances of high molecular weight formed by the polymerization of monomers, molecule with low molecular weight. https://images.app.goo.gl/MMQ3eRPaeCq6V2sp7 Many common classes of polymers are composed of hydrocarbons, compounds of carbon and hydrogen. These polymers are specifically made of carbon atoms bonded together, one to the next, into long chains that are called the backbone of the polymer. https://images.app.goo.gl/qEXHdzFG26wKfSMe8 There are polymers that contain only carbon and hydrogen atoms. EXAMPLES: Polyethylene, polypropylene, polybutylene, polystyrene and polymethylpentene Polyvinyl chloride (PVC) has chlorine attached to the all-carbon backbone. Teflon has fluorine attached to the all-carbon backbone.  NATURAL POLYMERS Occur naturally and can be extracted They are often water-based. Ex: Silk, DNA, proteins, cellulose, starch https://images.app.goo.gl/4ATuBMpM96HQQct37  SYNTHETIC POLYMERS Derived from petroleum oil Ex: Epoxy, Teflon, polyethylene, polyester https://images.app.goo.gl/g6NvtfCW4kLYjzKn9  HEAT CAPACITY/HEAT CONDUCTIVITY The extent to which the plastic or polymer acts as an effective insulator against the flow of heat. (The polystyrene in disposable plastic glasses isn't a very good insulator. However, blowing air through styrene while it is being polymerized gives the Styrofoam used for disposable coffee cups, which is a much better insulator.) https://images.app.goo.gl/b8M9w79cF3UxrFab7  THERMAL EXPANSION The extent to which the polymer expands or contracts when heated or cooled. Silicone is often used to seal glass windows to their frames because it has a very low coefficient of thermal expansion. https://images.app.goo.gl/ykCcEjja2qJFGVt59  CRYSTALLINITY The extent to which the polymer chains are arranged in a regular structure instead of a random fashion. Some polymers, such as Silly Putty and Play Dough, are too amorphous and lack the rigidity needed to make a useful product. Polymers that https://images.app.goo.gl/1L8Cocxbw6ge6aPq8 are too crystalline often are also too brittle.  PERMEABILITY The tendency of a polymer to pass extraneous materials Polyethylene is used to wrap foods because it is 4000 times less permeable to oxygen then polystyrene. https://images.app.goo.gl/8BzhkPchMjGHkVLf9  ELASTIC MODULUS The force it takes to stretch the plastic in one direction. https://images.app.goo.gl/g39dPU2PbG6iD3vN8  TENSILE STRENGTH The strength of the plastic. (The force that must be applied in one direction to stretch the plastic until it breaks.) https://images.app.goo.gl/g39dPU2PbG6iD3vN8  RESILIENCE The ability of the plastic to resist abrasion and wear. https://images.app.goo.gl/4xciLnzXe6pfxzP77  REFRACTIVE INDEX The extent to which the plastic affects light as it passes through the polymer. https://images.app.goo.gl/Fdu5GrgkAsKHsgTr5 RESISTANCE TO ELECTRIC CURRENT Most polymers are insulators There is a growing interest in conducting polymers, which can be charged and discharged, and photoconducting polymers that can pick up an electric charge when exposed to light. https://images.app.goo.gl/kXv7ChqE345TQgFg8 APPLICATION AND PROCESSING OF POLYMERS  OBJECTIVES ▪ To discuss methods of fabricating polymers ▪ To discuss different types of plastics ADDITION POLYMERIZATION Monomers are coupled through their multiple bonds. CONDENSATION POLYMERIZATION Used to synthesize commercially important polymers. In this polymerization, two molecules are joined to form a larger molecule by elimination of a small molecule, such as H2O. PLASTICS are polymeric solids that can be formed into various shapes, usually by the application of heat and pressure. https://images.app.goo.gl/sU471T3N3mzg6qWYA  Type of plastics that can be reshaped with the application of heat. Tangled (no cross-links) polymer chains Weak forces of attraction between chains Softens when heated Example: PET (Polyethylene https://images.app.goo.gl/As28Nk9456TeHEFC7 Terephthalate) bottles.  Plastics which can not be reshaped readily. Chains held by strong covalent cross- linking bonds They are shaped through irreversible chemical processes. Remains hard when heated. https://images.app.goo.gl/nSED4Tow7Kaj4sYe6 PLASTICS are numbered from 1 to 7 to indicate its type. This is primarily placed not for the consumers, but for the producers to ease code-communication, and for recyclers for sorting. https://images.app.goo.gl/s6NYvmjx13FLy7hz6 https://images.app.goo.gl/Sxp8PJz7dakzDoSaA Lawrence S. Brown and Thomas A. Holme (2018), Chemistry for Engineering Students : Cengage Learning Roxy Wilson (2018), Solutions to Red Exercises: Chemistry: The Central Science : United Kingdom: Pearson Theodore E. Brown, et. al.(2018), Chemistry: The Central Science (14th Edition) : United Kingdom: Pearson Unknown Author (2018), Chemistry in Context: McGraw-Hill Education Chang, Raymond and Kenneth A. Goldsby (2016). Chemistry. New York: McGraw Hill International Edition. Online References: http://chemed.chem.purdue.edu/genchem/topicreview/index.php http://www.sparknotes.com/chemistry/ http://m.learning.hccs.edu/faculty/laimutis.bytautas/chem1411