Presentation on theme: "Edexcel BTEC Level 1/2 First Award in Engineering"— Presentation transcript:
1 Edexcel BTEC Level 1/2 First Award in Engineering Revision Guide and information
2 What to expect / Important Information Date of Examination: Wednesday 22nd January Examination duration: 1 Hour Format of Examination: The exam will be online, requiring you to answer questions on a computer. The questions will vary in style, some being multiple choice, some connecting answers to each other and other requiring extended written answers. This examination counts for 25% of your entire grade, and so is extremely important! By securing a good grade now, you will have one less examination to worry about in June/July when you sit your GCSE examinations. Remember there are 3 sections that the questions in the examination can come from. We have covered all of these in detail during our examination preparation, and will continue to do work on this until the examination date.
3 Topics / ContentLearning aim B: Know about developments in engineering materials and technologies Topic B1: Modern and smart materials in engineering Applications, characteristics, properties and advantages/disadvantages of the following modern and smart materials used in engineering: ● modern composite materials – glass reinforced plastic (GRP), carbon fibre, Kevlar® ● modern high-performance materials – tungsten, titanium, superalloys (nickel based, cobalt based), ceramics (boron carbide, cubic boron nitride, zirconia) ● smart materials – shape memory alloys (SMAs), shape memory polymers, electrochromic, piezoelectric actuators and transducers. Topic B2: Modern material foams in engineering Applications, characteristics and advantages/disadvantages of metallic foams as used in the automotive, biomedical and aerospace sectors e.g. aluminium, steel. Topic B3: Modern material processes in engineering Process, applications, characteristics and advantages/disadvantages of powder metallurgy: powder mixing/blending, pressing/compacting, sintering. Topic B4: New technologies in engineering Applications, characteristics and advantages/disadvantages of the following new technologies used in engineering sectors: ● optical fibres as used in the communications sector ● hydrogen fuel cells, surface nanotechnology and telematics as used in the automotive sector ● blended wing bodies as used in the aerospace sector ● bionics as used in the biomedical sector.
4 Topics / ContentTopic B1: Modern and smart materials in engineering Applications, characteristics, properties and advantages/disadvantages of the following modern and smart materials used in engineering: Fiberglass (also called glass-reinforced plastic, GRP, glass-fiber reinforced plastic, or GFRP) is a fiber reinforced polymer made of a plastic matrix reinforced by fine fibers of glass. Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes. The plastic matrix may be epoxy, a thermosetting plastic (most often polyester) or thermoplastic. Common uses of fiberglass include high performance aircraft (gliders), boats, automobiles, baths, hot tubs, water tanks, roofing, pipes, cladding, casts, surfboards and external door skins.
5 Topics / ContentTopic B1: Modern and smart materials in engineering Applications, characteristics, properties and advantages/disadvantages of the following modern and smart materials used in engineering: Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. To produce carbon fiber, the carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber as the crystal alignment gives the fiber high strength-to-volume ratio (making it strong for its size). Several thousand carbon fibers are bundled together to form a tow, which may be used by itself or woven into a fabric. The properties of carbon fibers, such as high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion, make them very popular in aerospace, civil engineering, military, and motorsports, along with other competition sports. However, they are relatively expensive when compared to similar fibers, such as glass fibers or plastic fibers. Carbon fibers are usually combined with other materials to form a composite. When combined with a plastic resin and wound or molded it forms carbon fiber reinforced polymer (often referred to as carbon fiber) which has a very high strength-to-weight ratio, and is extremely rigid although somewhat brittle. However, carbon fibers are also composed with other materials, such as with graphite to form carbon-carbon composites, which have a very high heat tolerance.
6 Topics / ContentTopic B1: Modern and smart materials in engineering Applications, characteristics, properties and advantages/disadvantages of the following modern and smart materials used in engineering: Kevlar® is a material formed by combining para-phenylenediamine and terephthaloyl chloride. Aromatic polyamide (aramid) threads are the result. They are further refined, by dissolving the threads and spinning them into regular fibres. When woven, Kevlar® forms a strong and flexible material. If layers of the woven Kevlar® are combined with layers of resin, the resulting ‘rigid’ material is light and has twenty times the strength of steel. It is also superior to specialist metal alloys. However, Kevlar® is expensive due to the demands of the manufacturing process and the need for specialist equipment. There are three main types of Kevlar®; 1. Kevlar® is used as a reinforcement material for some car tyres and bicycle tyres. It helps dramatically reduce puncture rates. This standard of tyre is more expensive than ordinary road tyres. They are of particular use with 4 x 4 vehicles, especially when the vehicle is being used off road and far away from recovery services. 2. Kevlar® 29 is used in the manufacture of body armour (panels) for lightweight military vehicles. A good example is the US Army’s ‘Bradley Fighting Vehicle’. This has been used extensively in Iraq and Afghanistan. Kevlar® 29 was selected for its armour, because it is lightweight and withstands attack from RPGs. The Kevlar® 29 panels protect the soldiers inside the vehicle. Kevlar® 29 is ideal because it is lightweight and non-flammable and it offers protection from high temperatures (fire bombs, Molotov cocktails etc...). Kevlar® 29 can also withstand the harsh environmental conditions, found in hot climates. 3. Kevlar® 49 is used for specialist boat hulls and in the aerospace industry. It is popular as a material for boats because it is lightweight and can withstand a considerable amount of force (torque - twisting force), tensile stress and impact. Hulls manufactured from traditional materials, such as fibreglass, are limited in their resistance to forces and stress. Also, a lightweight boat is faster on the water and uses less fuel to complete distances. Eurofighter is relatively light compared to other similar fighter jets, due to the selection of Kevlar ® 49 as a material in its manufacture. This means that it can fly faster and further, before in-flight refuelling is needed. It is more agile than its rivals due to excellent force (torque - twisting force) and tensile stress resistance. The plane is more likely to survive being hit by small arms fire, compared to other fighter planes, as Kevlar ® 49 has excellent impact resistance.
7 Topics / ContentTopic B1: Modern and smart materials in engineering Applications, characteristics, properties and advantages/disadvantages of the following modern and smart materials used in engineering: Tungsten, also known as wolfram, is a chemical element. The word tungsten comes from the Swedish language tung sten directly translatable to heavy stone. A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as a metal in Its important ores include wolframite and scheelite. The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the elements. Also remarkable is its high density of 19.3 times that of water, comparable to that of uranium and gold, and much higher (about 1.7 times) than that of lead. Tungsten with minor amounts of impurities is often brittle and hard, making it difficult to work. However, very pure tungsten, though still hard, is more ductile, and can be cut with a hard-steel hacksaw. Tungsten's many alloys have numerous applications, most notably in incandescent light bulb filaments, X-ray tubes (as both the filament and target), electrodes in TIG welding, and superalloys. Tungsten's hardness and high density give it military applications in penetrating projectiles. Tungsten compounds are also often used as industrial catalysts. Tungsten is the only metal from the third transition series that is known to occur in biomolecules, where it is used in a few species of bacteria andarchaea. It is the heaviest element known to be used by any living organism. Tungsten interferes with molybdenum and copper metabolism, and is somewhat toxic to animal life.
8 Topics / ContentTopic B1: Modern and smart materials in engineering Applications, characteristics, properties and advantages/disadvantages of the following modern and smart materials used in engineering: Titanium is a chemical element with the symbol Ti and atomic number 22. It is a lustrous transition metal with a silver color, low density and high strength. It is highly resistant to corrosion in sea water, aqua regia and chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791 and named by Martin Heinrich Klaproth for the Titans of Greek mythology. The element occurs within a number of mineral deposits, principally rutile and ilmenite, which are widely distributed in the Earth's crustand lithosphere, and it is found in almost all living things, rocks, water bodies, and soils. The metal is extracted from its principal mineral ores via the Kroll process or the Hunter process. Its most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride (TiCl4), a component of smoke screens and catalysts; and titanium trichloride(TiCl3), which is used as a catalyst in the production of polypropylene. Titanium can be alloyed with iron, aluminium, vanadium, molybdenum, among other elements, to produce strong lightweight alloys for aerospace (jet engines, missiles, and spacecraft), military, industrial process (chemicals and petro-chemicals, desalination plants, pulp, and paper), automotive, agri-food, medical prostheses, orthopedic implants, dental and endodontic instruments and files, dental implants, sporting goods, jewelry, mobile phones, and other applications. The two most useful properties of the metal are corrosion resistance and the highest strength-to-weight ratio of any metal. In its unalloyed condition, titanium is as strong as some steels, but 45% lighter. There are two allotropic forms and five naturally occurring isotopes of this element, 46Ti through 50Ti, with 48Ti being the most abundant (73.8%). Titanium's properties are chemically and physically similar to zirconium, as both of them have the same number of valence electrons and are in the same group in the periodic table.
9 Topics / Content Topic B1: Modern and smart materials in engineering Applications, characteristics, properties and advantages/disadvantages of the followingmodern and smart materials used in engineering:A superalloy, or high-performance alloy, is an alloy that exhibits excellent mechanical strength and resistance to creep (tendency for solids to slowly move or deform under stress) at high temperatures; good surface stability; and corrosion and oxidation resistance. Superalloys typically have a matrix with an austenitic face-centered cubic crystal structure. A superalloy's base alloying element is usually nickel, cobalt, or nickel-iron. Superalloy development has relied heavily on both chemical and process innovations and has been driven primarily by the aerospace and power industries. Typical applications are in the aerospace, industrial gas turbine and marine turbine industries, e.g. for turbine blades for hot sections of jet engines, and bi-metallic engine valves for use in diesel and automotive applications.Examples of superalloys are Hastelloy, Inconel (e.g. IN100, IN600, IN713), Waspaloy, Rene alloys (e.g. Rene 41, Rene 80, Rene 95, Rene N5), Haynes alloys, Incoloy, MP98T, TMS alloys, and CMSX (e.g. CMSX-4) single crystal alloys.Superalloys are commonly used in parts of gas turbine engines that are subject to high temperatures and require high strength, excellent high temperature creep resistance, fatigue life, phase stability, and oxidation and corrosion resistance.
10 Topics / ContentTopic B1: Modern and smart materials in engineering Applications, characteristics, properties and advantages/disadvantages of the following modern and smart materials used in engineering: A shape-memory alloy (SMA, smart metal, memory metal, memory alloy, muscle wire, smart alloy) is an alloy that "remembers" its original, cold-forged shape: returning to the pre-deformed shape when heated. This material is a lightweight, solid-state alternative to conventional actuators such as hydraulic, pneumatic, and motor-based systems. Shape-memory alloys have applications in industries including automotive, aerospace, biomedical and robotics. Shape-memory polymers (SMPs) are polymeric smart materials that have the ability to return from a deformed state (temporary shape) to their original (permanent) shape induced by an external stimulus (trigger), such as temperature change. Electrochromism is the phenomenon displayed by some materials of reversibly changing color when a burst of charge is applied. Various types of materials and structures can be used to construct electrochromic devices, depending on the specific applications. The Electrochromism occurs due to the electrochemical redox reactions that take place in electrochromic materials. One good example of an electrochromic material is polyaniline which can be formed either by the electrochemical or chemical oxidation of aniline. If an electrode is immersed in hydrochloric acid which contains a small concentration of aniline, then a film of polyaniline can be grown on the electrode. Depending on the oxidation state, polyaniline can either be pale yellow or dark green/black. Other electrochromic materials that have found technological application include the viologens and polyoxotungstates. Other electrochromic materials include tungsten oxide (WO3), which is the main chemical used in the production of electrochromic windows or smart glass. NiO materials have been widely studied as counter electrodes for complementary electrochromic devices, in particular, smart windows. The world leading institutions on NiO efforts include National Renewable Energy Laboratory and Uppsala University. Piezoelectricity /piˌeɪzoʊˌilɛkˈtrɪsɪti/ is the electric charge that accumulates in certain solid materials (such as crystals, certain ceramics, and biological matter such as bone, DNA and various proteins) in response to applied mechanical stress. The word piezoelectricity means electricity resulting from pressure. It is derived from the Greek piezo or piezein (πιέζειν), which means to squeeze or press, and electric or electron (ήλεκτρον), which stands for amber, an ancient source of electric charge. Piezoelectricity was discovered in 1880 by French physicists Jacques and Pierre Curie.
11 Topics / ContentTopic B2: Modern material foams in engineering Applications, characteristics and advantages/disadvantages of metallic foams as used in the automotive, biomedical and aerospace sectors e.g. aluminium, steel. A metal foam is a cellular structure consisting of a solid metal, frequently aluminium, containing a large volume fraction of gas-filled pores. The pores can be sealed (closed-cell foam), or they can form an interconnected network (open-cell foam). The defining characteristic of metal foams is a very highporosity: typically 75–95% of the volume consists of void spaces making these ultralight materials. The strength of foamed metal possesses a power law relationship to its density; i.e., a 20% dense material is more than twice as strong as a 10% dense material. Metallic foams typically retain some physical properties of their base material. Foam made from non-flammable metal will remain non-flammable and the foam is generally recyclable back to its base material. Coefficient of thermal expansion will also remain similar while thermal conductivity will likely be reduced. Although there is a very large number of patents describing feasible topological structures, constitutive materials and production methods, metal foams cannot be considered a commodity and relatively few commercial producers are available worldwide of either closed or open cell foams.
12 Topics / ContentTopic B3: Modern material processes in engineering Process, applications, characteristics and advantages/disadvantages of powder metallurgy: powder mixing/blending, pressing/compacting, sintering. Powder metallurgy is the manufacturing science of producing solid parts of desired geometry and material from powders. Commonly known as powder metallurgy, it may also be referred to as powder processing considering that non-metal powders can be involved. Powders are compacted into a certain geometry then heated, (sintered), to solidify the part. The manufacturing advantages and disadvantages, as well as the applications for parts produced by this method, are discussed latter in the design and applications of powder metallurgy section. Powder metallurgy is the process of blending fine powdered materials, pressing them into a desired shape or form (compacting), and then heating the compressed material in a controlled atmosphere to bond the material (sintering). The powder metallurgy process generally consists of four basic steps: powder manufacture, powder blending, compacting, and sintering. Compacting is generally performed at room temperature, and the elevated-temperature process of sintering is usually conducted at atmospheric pressure. Optional secondary processing often follows to obtain special properties or enhanced precision. The use of powder metal technology, bypasses the need manufacture the resulting products by metal removal processes thereby reducing costs. Two main techniques used to form and consolidate the powder are sintering and metal injection molding. Recent developments have made it possible to use rapid manufacturing techniques which use metal powder for the products. Because with this technique the powder is melted and not sintered, better mechanical strength can be accomplished.
13 Topics / ContentTopic B4: New technologies in engineering Applications, characteristics and advantages/disadvantages of the following new technologies used in engineering sectors. An optical fiber (or optical fibre) is a flexible, transparent fiber made of high quality extruded glass (silica) or plastic, slightly thicker than a human hair. It can function as a waveguide, or “light pipe”, to transmit light between the two ends of the fiber. The field of applied science and engineeringconcerned with the design and application of optical fibers is known as fiber optics. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication. Fibers are used instead of metalwires because signals travel along them with less loss and are also immune to electromagnetic interference. Fibers are also used for illumination, and are wrapped in bundles so that they may be used to carry images, thus allowing viewing in confined spaces. Specially designed fibers are used for a variety of other applications, including sensors and fiber lasers. Optical fibers typically include a transparent core surrounded by a transparent cladding material with a lower index of refraction. Light is kept in the core by total internal reflection. This causes the fiber to act as a waveguide. Fibers that support many propagation paths or transverse modes are calledmulti-mode fibers (MMF), while those that only support a single mode are called single-mode fibers (SMF). Multi-mode fibers generally have a wider core diameter, and are used for short-distance communication links and for applications where high power must be transmitted. Single-mode fibers are used for most communication links longer than 1,000 meters (3,300 ft). Joining lengths of optical fiber is more complex than joining electrical wire or cable. The ends of the fibers must be carefully cleaved, and then spliced together, either mechanically or by fusing them with heat. Special optical fiber connectors for removable connections are also available.
14 Topics / ContentTopic B4: New technologies in engineering Applications, characteristics and advantages/disadvantages of the following new technologies used in engineering sectors. Hydrogen is high in energy, yet an engine that burns pure hydrogen produces almost no pollution. NASA has used liquid hydrogen since the 1970s to propel the space shuttle and other rockets into orbit. Hydrogen fuel cells power the shuttle's electrical systems, producing a clean byproduct - pure water, which the crew drinks. A fuel cell combines hydrogen and oxygen to produce electricity, heat, and water. Fuel cells are often compared to batteries. Both convert the energy produced by a chemical reaction into usable electric power. However, the fuel cell will produce electricity as long as fuel (hydrogen) is supplied, never losing its charge. Fuel cells are a promising technology for use as a source of heat and electricity for buildings, and as an electrical power source for electric motors propelling vehicles. Fuel cells operate best on pure hydrogen. But fuels like natural gas, methanol, or even gasoline can be reformed to produce the hydrogen required for fuel cells. Some fuel cells even can be fueled directly with methanol, without using a reformer. In the future, hydrogen could also join electricity as an important energy carrier. An energy carrier moves and delivers energy in a usable form to consumers. Renewable energy sources, like the sun and wind, can't produce energy all the time. But they could, for example, produce electric energy and hydrogen, which can be stored until it's needed. Hydrogen can also be transported (like electricity) to locations where it is needed.
15 Topics / ContentTopic B4: New technologies in engineering Applications, characteristics and advantages/disadvantages of the following new technologies used in engineering sectors. In modern times nanotechnology has become increasingly important. It has many uses from developing sports equipment to medical applications. There are however some concerns about its use. Nanotechnology The use and control of tiny matter is called nanotechnology. The tiny matter is referred to as nanoparticles. These particles are measured in nanometres (nm). A nanometre is one billionth of a metre ( m). Nanotechnology is concerned with the use and control of structures that are nanometres in size. Some of these nanoparticles occur naturally, for example in volcanic ash. Some occur by accident, for example during the combustion of fuels. Many occur by design. Properties of nanoparticles Nanoparticles of a material show different properties compared to larger particles of the same material. Forces of attraction between surfaces can appear to be weak on a larger scale, but on a nanoscale they are strong. One reason for this is the surface area to volume ratio. In nanoparticles this is very large. Atoms on the surface of a material are often more reactive than those in the centre, so a larger surface area means the material is more reactive. Nanoparticles have more surface area to volume than larger particles. The diagram shows this idea. The cube on the left has the same volume as the smaller cubes added together on the right. However, the total surface area is much larger for the smaller cubes. Use of nanoparticles Nanoparticles are used in products that are currently available. sports equipment: nanoparticles are added to materials to make them stronger whilst often being lighter. They have been used in tennis rackets, golf clubs and shoes clothing: silver nanoparticles have been added to socks. This stops them from absorbing the smell of sweaty feet as the nanoparticles have antibacterial properties healthcare: nanoparticles are used in sunscreens. They offer protection and can be rubbed in so there are no white marks. Harmful effects There are some concerns that nanoparticles may be toxic to people. They may be able to enter the brain from the bloodstream and cause harm. Some people think more tests should take place before nanoparticles of a material are used on a wider scale.
16 Topics / ContentTopic B4: New technologies in engineering Applications, characteristics and advantages/disadvantages of the following new technologies used in engineering sectors. Telematics typically is any integrated use of telecommunications and informatics, also known as ICT (Information and Communications Technology). Hence the application of telematics is with any of the following: Lexus Gen V navigation system The technology of sending, receiving and storing information via telecommunication devices in conjunction with affecting control on remote objects. The integrated use of telecommunications and informatics, for application in vehicles and with control of vehicles on the move. Telematics includes but is not limited to Global Positioning System technology integrated with computers and mobile communications technology in automotive navigation systems. Most narrowly, the term has evolved to refer to the use of such systems within road vehicles, in which case the term vehicle telematics may be used. In contrast telemetry is the transmission of measurements from the location of origin to the location of computing and consumption, especially without affecting control on the remote objects. Telemetry is typically applied in testing of flight objects but has multiple other uses.
17 Topics / ContentTopic B4: New technologies in engineering Applications, characteristics and advantages/disadvantages of the following new technologies used in engineering sectors. Blended Wing Body (BWB or Hybrid Wing Body, HWB) aircraft have a flattened and airfoil shaped body, which produces most of the lift, the wings contributing the balance. The body form is composed of distinct and separate wing structures, though the wings are smoothly blended into the body. By way of contrast, flying wing designs are defined as a tailless fixed-wing aircraft which has no definitefuselage, with most of the crew, payload and equipment being housed inside the main wing structure. A blended wing body has lift-to-drag ratio 50% greater than a conventional airplane. Thus BWB incorporates design features from both a futuristic fuselage and flying wing design. The purported advantages of the BWB approach are efficient high-lift wings and a wide airfoil-shaped body. This enables the entire craft to contribute to lift generation with the result of potentially increased fuel efficiency and range.
18 Topics / ContentTopic B4: New technologies in engineering Applications, characteristics and advantages/disadvantages of the following new technologies used in engineering sectors. Bionics (also known as bionical creativity engineering) is the application of biological methods and systems found in nature to the study and design ofengineering systems and modern technology. The word bionic was coined by Jack E. Steele in 1958, possibly originating from the technical term bion (pronounced bee-on) (from Ancient Greek: βίος), meaning 'unit of life' and the suffix -ic, meaning 'like' or 'in the manner of', hence 'like life'. Some dictionaries, however, explain the word as being formed as aportmanteau from biology + electronics. It was popularized by the 1970s television series The Six Million Dollar Man and The Bionic Woman, which were based upon the novel Cyborg by Martin Caidin, which was influenced by Steele's work, and feature humans given superhuman powers by electromechanical implants The transfer of technology between lifeforms and manufactures is, according to proponents of bionic technology, desirable because evolutionary pressure typically forces living organisms, including fauna and flora, to become highly optimized and efficient. A classical example is the development of dirt- and water-repellent paint (coating) from the observation that the surface of the lotus flower plant is practically unsticky for anything (the lotus effect). The term "biomimetic" is preferred when reference is made to chemical reactions. In that domain, biomimetic chemistry refers to reactions that, in nature, involve biological macromolecules (for example, enzymes or nucleic acids) whose chemistry can be replicated using much smaller molecules in vitro. Examples of bionics in engineering include the hulls of boats imitating the thick skin of dolphins; sonar, radar, and medical ultrasound imaging imitating theecholocation of bats. In the field of computer science, the study of bionics has produced artificial neurons, artificial neural networks, and swarm intelligence. Evolutionary computation was also motivated by bionics ideas but it took the idea further by simulating evolution in silico and producing well-optimized solutions that had never appeared in nature.