Materials Used to Make Automotive Engine Blocks - Research Paper Example

AUTOMOTIVE MATERIALS By Name Course Instructor Institution City/State Date The History and Evolution of Materials Used To Make Automotive Engine Blocks In 1864, Siegfried Marcus built the first internal combustion engine utilised in the automobile, and that was working successfully [1]. The engine was a two- stroke, upright single-cylinder engine that as well used a carburettor for delivering the engine’s fuel. Besides that, the cart having four wheels housed the engine and ran successfully with its own power. In view of this, Marcus did not just create the first engines, he had as well created the first automobile, almost two decades prior to Gottlieb Daimler’s automobile. Basically, the engine contains a number of components such as timing chains, camshafts, pistons, rocker arms, and other different parts, which are made of different material. When these components are removed, the cylinder block/engine block can be seen, which the core of the engine is. The engine block is without a doubt the engine’s strongest component housing many parts found inside the contemporary engine. Given that it is somewhat a big component; the engine block weighs 20 to 25 per cent of the engine total weight; thus, creating the need to reduce the weight of the block. The majority of the early engine blocks were created from alloys of cast iron mainly because of its low cost as well as high strength. However, as designs of the engine turned out to be more complex, the engine weight had increased. Subsequently, the need amongst producers to utilise lighter alloys, which were similarly strong as the cast irons materialised. For example, aluminium alloys was considered a perfect substitute for cast irons. Even though they were sparingly used in the 1930’s (because durability issues, the use of aluminium alloy in the engine blocks grew during the 1960’s as well as 1970’s with the goal of increasing performance as well as fuel efficiency [2]. Collectively, aluminium alloys and cast iron were exclusively utilised for fabricating engine blocks. However, a new-fangled material process has lately made the magnesium alloy appropriate for manufacturing engine blocks. The alloy, known as AMC-SC1 has less weight as compared to aluminium alloys and cast iron; thus, representing new potentials in manufacturing of engine blocks. Besides that, a new process of manufacturing has made compacted graphite cast iron a feasible substitute to grey cast iron for manufacturing diesel engine blocks. Akin to the magnesium alloys, compacted graphite cast iron material provides a lower weight and higher strength as compared to grey cast iron [3]. For decades, aluminium castings have widely been utilised in different parts of the automobile. More recently, the engine blocks’ material, which undeniably is amongst the heavier parts, has being changed from cast iron to aluminium alloys leading to a considerable reduction in weight [4]. Magnesium alloy, particularly Mg-Al-Sr alloys has been developed recently and is used in engine blocks because of its lightweight and heat resistance. The magnesium alloys are utilized by BMW in production of diecast engine blocks due to their outstanding mechanical properties, excellent castability and good resistance to corrosion [5-6]. Magnesium alloys added with strontium have improved creep resistance as compared to aluminum alloys and cast iron. The Chemical Composition and Mechanical Properties of the Automotive Engine Block Materials Aluminium Alloys Chemical composition of aluminium alloys based on ANSI/AA; Aluminium Alloy 360 die casting has a nominal composition of magnesium (o.5%) and silicon (9.0%); A360 has 0.5% magnesium and 9.5% silicon; 380 and A380 has 3.5% copper and 8.5 silicon; 383 has 2.5% copper and 10.5 silicon; 384 has 3.8% copper and 11% silicon; B390 has 4.5% copper and 17% silicon; 413 and A413has 12% silicon; C443 has5% silicon; and 518 has 8% magnesium and the remainder is pure aluminium [7-8]. With regard to mechanical properties, aluminium alloys mechanical propertied rely on heat treatment, composition, cold working, as well as other factors. Besides that, a number of properties vary substantially in similar compositions based on the product type or history of processing. The use of Aluminium alloys are limited to only temperatures that are moderately elevated due to their melting point that is relatively low; 4820C to 649°C. A number of aluminium alloys start weakening and softening appreciably at lower temperatures of 93°C while others retain their strength at 204°C temperatures. Besides that, aluminium alloys’ hardness, strength, as well as modulus of elasticity decrease when temperature increases while rising temperatures increases elongation [9]. The aluminium mechanical properties improves when temperature decrease [10]. For instance, tests carried out at temperatures below -196°C exhibit that when temperature is reduced, it results to an increased elongation and strength. Decrease in temperature’s also result in increased fatigue strength and modulus of elasticity, and no proof of low-temperature embrittlement. Cast Iron Cast iron is produced from pig iron (re-melting), normally with a number of quantities of scrap steel, scrap iron as well as a number of alloys, like Copper, Chromium, Nickel and Molybdenum [11-12]. Silicon and carbon are the main alloying elements of cast iron. Based on the application, the silicon and carbon content are reduced by iron foundries to the required levels from 1 to 3 per cent and 2 to 3.5 per cent respectively. During the melting process, other elements as well as alloys are as well added in relation to the different requirements. With the diverse melting as well as inoculation processes, various cast irons can be generated. The chemical composition of the majority of grey cast irons is 1 to 3 per cent silicon, 2.5 to 4.0 per cent carbon, while the remaining is pure iron [13]. Still, in some applications the chemical composition aspect can be indicated so as to guarantee the iron suitability for certain needs. For instance, the content range of an alloy can be specified so as to make sure a sufficient reaction to heat treatment or to offer oxidization resistance or strength. Besides that, a minimum content of carbon can be specified so as to offer sufficient thermal shock resistance. In terms of mechanical properties, cast iron is virtually a brittle, non-malleable metal and very inflexible. The dampening as well as stiffness properties of cast iron makes it an outstanding material for making parts and tool frames of machines. All grey irons, microscopically have flake graphite distributed within the silicon-iron matrix. Iron properties are influenced by the percentage of graphite in it, the flakes length as well as how they are dispersed in the matrix [14]. Cast iron basic hardness and strength iron is offered through the metallic matrix wherein the graphite comes about. A completely pearlitic matrix is distinctive of grey irons’ high strength, and the majority of castings are generated with a matrix microstructure of pearlite as well as ferrite so as to get intermediate strength and hardness. Heat treatment and/or additions of alloy may be utilised for producing grey iron with an acicular matrix structure or with a very fine pearlite [15]. Magnesium Alloy They are different types of magnesium alloys each having different chemical composition; AE44 has 92% magnesium, 4% aluminum, and 4%; AJ62A has 89.8-91.8% magnesium, 5.6 to 6.6% aluminum, 0.26 to 0.5% manganese, 0.2% zinc, 0.08 silicon, and 2.1to 2.8% of other metals such as iron, copper, Beryllium, and nickel; WE43 has 93.6% magnesium, 4% Yttrium, 2.25% Neodymium, and 0.15% Zirconium; and AZ31B has 96% magnesium, 2.5-3.5% magnesium, 0.7-1.3% zinc, 0.05% silicon and 0.2 manganese [16-17]. The magnesium alloys mechanical properties are determined in line with ASTM procedures where appropriate. In line with ASTM procedure, the magnesium alloys yield strength is described as the stress upon which the stress-strain curve strays 0.2% from the modulus line. Basically, the compressive yield strength of the cast magnesium alloys is considerably equal to its tensile yield strength. Still, the compressive yield strength of most wrought magnesium alloys is 60 to 70% of the tensile yield strength. The magnesium alloy mechanical properties are affected by the time of billet preheating, speed of extrusion and temperature, high temperatures as well as Long preheating times and speeds generate properties akin to those of aluminium alloys, in order to produce high properties, heating times should be short and at low speeds and temperatures [10]. Increasing the content zinc reduces extrusion speed sensitivity with respect to mechanical properties. Manufacturing Method of Each Automotive Engine Block Material Aluminium alloy First, bauxite is extracted through open cast mining, crushed as well as washed before being purified to alumina through the Bayer process. The Bayer process is anchored in the fact that alumina is amphoteric, silica is an acidic oxide, and both Titania and iron oxide are basic [18]. After the ore is crushed, it is mixed with caustic soda) solution, and then heated. This result in the dissolving of alumina as well as numerous reactive crystalline forms of silica, which do not affect titania, iron oxide, or the majority of silica that have combined already with the other elements. When silica and alumina solution is cooled, first the complex aluminosilicate sand is precipitated out prior to changing the conditions of the process so as to allow crystallization of pure aluminum hydroxide. Basically, this is accelerated by first adding aluminum hydroxide crystal in small quantities to act as locations for the growth of the crystal. Subsequently, the aluminum hydroxide pure crystals are heated up to 2012 Fahrenheit, resulting in decomposition of alumina as well as water. The next step is alumina reduction, where Aluminum metal is not created through alumina electrochemical reduction, but it is reduced through electrical and chemical energy combination [19]. In its ionic form, and a temperature between 950 and 980oC, Alumina becomes a covalently bonded oxide making it possible to be electrolyzed. Afterwards, alumina is dissolved in molten cryolite forming complex anionic oxyfluorides. A lot of energy is needed in the electrolysis process since affinity of aluminum for oxygen makes the reaction exceedingly exothermic. Using carbon electrodes, the electrolysis is performed in the electric furnace, where a current of almost 170000 amperes is passed in the pots having a voltage drop of nearly 4.4 volts. In consequence, this allows the pot to be maintained at an operating temperature of almost 1832°F resulting in alumina reduction. Consequently, the carbon cathode collects the molten aluminium and is drained off at a daily rate of nearly one tonne [20]. To produce aluminium alloys, other elements are added deliberately so as to somehow improve the properties. A number of alloys are manufactured with the goal of improving strength and retaining the required aluminium properties, most especially its corrosion resistance as well as lightness. Alloying is performed through adding appropriate alloying element quantities to the molten aluminium. This is performed through the special holding furnace, where the element such as silicon, iron, magnesium, or the hardener or master alloys are added directly. Silicon and iron are directly added to specific reduction cells, given that the temperature of operation is quite high (1760°F); thus, facilitating the solution. Considering that magnesium is volatile, it is added only prior to casting at almost 1364°F [21]. In most aluminium plants (such as extrusion plants and rolling mills), higher melting point elements are added in the hardener form or master alloy; thus, facilitating the elements’ solution at a lower temperature. The majority of aluminium alloys are in actual fact true solid solutions wherein alloying elements atoms of substitutes the crystal lattice’s aluminium atoms. Cast Iron Cast irons are made through four steps; design, pattern making, moulding and casting [22]. In the design stage, for ideas are converted into solid metal a planned approach is needed that considers the object function together with its appearance. For engine blocks, the conditions as well as stresses the engine operates under must be taken into account. In this case, engineering department in the automobile company offer complex and detailed manufacturing drawings. The drawings/elevations are supplied by the architects, which normally have to be reproduced given that the drawings display precise dimensions in order that the subsequent phase, the Pattern Making, may be initiated. After the approval of the designs, the next phase is the Pattern Making, usually in wood but occasionally using plastics or fibreglass. Imperatively, the patterns must be precisely in the shape of the finished item and their dimensions should be precisely the same. If looked after, patterns may be re-used so as to make more moulds, but any mistake or irregularity will be replicated in the casting [23]. Besides that, patterns have to allow for the metal shrinkage during cooling process and as well generate runners or channels so as to facilitate the flowing of the molten metal into the mould as well as risers to facilitate the escaping of gases. The next stage is the making of the mould in sand wherein the molten iron may be poured. In this case, the patterns are placed in the sand, and are mixed with resin or clay, and casting shape is achieved when the pattern is removed. Normally, for the actual pouring the moulds are made in two parts as well as housed in boxes. A cavity where the molten iron will be poured is created when the mould two halves are placed lying on top of the other [24]. Imperatively, the runner system is a critical factor during mould making. The runner system is a network of channels allowing the molten iron to pour into the mould. Imperatively, this process needs greater expertise and skill considering that the molten iron failure to run quickly into the mould will result in solidification before it attains the needed casting shape. Still, if it runs into the mould too violently or rapidly it may damage the mould and the cast may be spoilt. The majority of castings, specifically columns as well as bollards have hollow cavities or centres. In this case, the casting internal shape is created by creating a sand core, and subsequently placing it in the mould cavity. This skill also needs great skill in making sure the metal form and thickness is precise. The core is filled with molten iron such that when braking out the casting, the internal sand core remaining is removed leaving a cavity. The sand mould while breaking out the casting is destroyed, still, new moulds may be created from the pattern utilising the sand after recycling. The final part is casting, which is mainly associated with foundries, and where iron is melted and poured at 1,350 oC [25]. In all foundries, safety is considered a high priority. The furnace is first loaded carefully so as to make sure the grade of the iron needed has precise chemical characteristics. Subsequently, melting of the iron is carried out in the furnace before being poured off into the awaiting moulds while foundry or Slag waste is amassed in one side for discarding. After cooling the Iron, the moulds are broken out while excess iron are removed through the fettling process, which as well involves shot blasting as well as grinding so that the finished casting may be achieved [26]. Magnesium Alloy Manufacturing method of magnesium may be divided roughly into thermal reduction and electrolysis. In the thermal reduction process, magnesium oxide is extracted from Magnesium Ores, where a reducing agent like ferro-silicon is added to it and under reduced pressure, the resulting material is refined through heating it to high temperature [27]. In the Electrolysis method, magnesium chloride is extracted from magnesium ores, and then through electrolysis magnesium is reduced to the metallic form [28]. The techniques of sand casting involve utilisation of small additions of Sulfur hexafluoride or Carbon dioxide into air; however, for aerospace castings Sulfur dioxide has been replaced with the gas mixture while pouring as well as during heat treatment process. In foundry technology, the majority of the other developments characterize espousals to magnesium general foundry developments practice intended for requirements like thinner sections production, better dimensional precision, effective utilisation of skilled labour, and so forth. Most magnesium pressure die castings are prepared in alloys that have almost 8 per cent Aluminium. Development of alloy so as to meet particular requirements involves utilisation of AM60 (6 per cent aluminium) so as to offer an improved impact strength needed for automotive castings as well as AS41 (0.7 per cent Silicon and 4 per cent aluminium) for high creep strength needed for advanced Volkswagen air-cooled engine versions [29]. Other alloys, which involve the addition of rare-earth metals or calcium to the versatile alloys containing aluminium, are yet to be commercially adopted because of their poor castability. All in all, magnesium-alloy castings are created in limited quantities through the gravity die process. Normally, die casting magnesium alloys takes place at higher gate velocities as compared to aluminium alloys because it is not as aggressive as molten aluminium towards steel. Therefore, magnesium alloys can be cast in cold chamber and hot chamber machines. Basically, the majority of magnesium alloys applications are fabricated through high pressure die casting because of the likelihood for low production cost and high production volume. In this case, die casting is achieved through forcing molten metal into mould through a narrow opening at high velocities of almost 20m/s [30]. During solidification s a high intensification pressure is applied, and pressure during the last solidification stages allows the metal to fill areas eventually improving the part’s internal integrity as well as reducing porosity. In die casting magnesium, almost 40 to 60 per cent of the metal turns out to be the scrap metal through the overflow as well as runner system. Strengthening Mechanism of Automotive Engine Block Materials Aluminium alloys The numerous strengthening mechanism of aluminum alloys; first mechanism is the work hardening also referred as cold working. In this mechanism, deformation at room temperature results in the new dislocations formation, which consequently makes more deformation challenging. In consequence, dislocations amass at the grain boundaries leading to an increase in strength [31]. Solid-solution hardening is another strengthening mechanism, and it describes an increasing hardening brought about by alloying elements (foreign atoms) in the aluminum crystal lattice. In this case, the foreign atoms make it harder for a grain to move dislocations leading t a pile up of dislocations as well as resulting strength increase. In fine-grain hardening, the refinement of grain results in an increased number of grain boundaries and consequently to more dislocation movement barriers, which is results to increased strength [32]. Another strengthening mechanism is heat treatment, which normally utilized to describe measures deliberately espoused to alter the material properties by exposing it to a high temperature and consequently altering its structure. Age hardening in aluminum alloys, is a crucial process, but heat treatment also consists of annealing as well as thermal softening, as discussed below. Age hardening is an effective strengthening mechanism involving a non-equilibrium situation, which under specific conditions may take place in the aluminum solid solution. At increased temperature, the alloying elements are homogenously dissolved in solid solution; still, when temperatures decrease the solubility of such elements is reduced. Therefore, in case the temperature is decreased suddenly, the alloying elements existing in the solid solution cannot precipitate; thus, making the solid solution supersaturated in such elements. Enduring exposure to faintly increased temperature or room temperature then makes the alloying constituents to precipitate out of solution resulting in the formation of fine particles that are distributed very uniformly. Such particles subsequently block the slip planes as well as deter the dislocations movement leading to a corresponding strength increase. Normally, age hardening occurs in three stages, specifically solution treatment, quenching followed by natural or artificial ageing [33]. In solution treatment, the alloying constituents present in the solid solution that are normally distributed non-uniformly all through the grain structure are dissolved so as to create a solid solution at a temperature between 860 and 1040 °F; thus, becoming homogenized. In the quenching phase, the metal is rapidly cooled down so as to ‘freeze in’ the homogeneity achieved during the solution treatment stage. Subsequently, cooling has to be performed slowly in order to prevent parts warping or distorting attributed to internal stresses. Imperatively, quenching affects crucial properties like toughness and corrosion; therefore, the cooling rate has to be defined precisely and alloy used together with the nature of semi-finished product has to be considered. In ageing, aluminum alloys are exposed to room temperatures (natural aging) or nearly 248 to 356 °F (artificial aging) [34]. In this case, alloying elements in the supersaturated solid solution precipitate out forming small particles which results in a corresponding increase in strength as well as hardness. Another method of increasing strength in aluminum alloys is through thermal softening, which is a heat treatment technique. Thermal softening is carried out at temperatures between 302 and 482°F. Still, the material strengthening through cold impact extrusion and rolling can make aluminum alloys to lose their ductility; thus, becoming brittle. Basically, softening aluminum alloys through annealing at temperatures beneath the recrystallization temperature leads to strength loss, but results in the so-called ‘half hard’ temper with ductility increasing enormously. In view of this, recrystallization annealing is performed at temperatures between 350 and 450 °C where cold worked alloys are softened completely so as to enable them to be further worked on. Annealing results in recrystallization, where entirely new grains grow from the deformed grains’ nuclei brought about by cold working; therefore, the entire crystal structure is for this reason created afresh and generates positive conditions for additional forming [35]. Cast Iron The mechanism for strengthening cast iron includes a number of processes such as age strengthening and heat treatment. In view of this, it has been proven statistically that at room temperature, 13.5 per cent of grey cast irons may age strengthen after being hold up for approximately nine weeks after the day of casting. In most cases, the aging amount is dependent on time while the time dependence is logarithmic following Avrami sigmoidal shape closely in many instances. Basically, cat Iron Age strengthening takes place both in the induction as well as cupola furnace irons. In Richards and Nicola study, they 21 one irons with 17 Gray iron from induction melting as well as the cupola furnace, 4 ductile irons, which includes a temper grade and quench; and one gray iron that has been revolutionized (accelerated aging) [36]. Besides that, Richards and Nicola tested 32 different irons from different, and observed that 28 irons had an age strengthening that was statistically significant. Besides that, hardness as well accelerates aging, especially in the matrix ferrite phase. As evidenced by kinetic studies, using a heat treatment cycle with relatively low temperature may accelerate the process of aging. This theory was demonstrated by revolutionizing experiment and cast experiments as evidenced in Richards and Nicola study. Another mechanism of strengthening cast irons is through heat treatment, which are normally utilised on mild or structural steels. Still, to achieve particular properties, it is imperative to change the cast iron microstructure by subjecting it to numerous heat treatments [37]. Such processes are carried out so as to produce a mixture of cementite and ferrite, which offers a suitable combination of properties. Generally, cast iron in the heat treatment process involves the heating as well as cooling of the alloy while in solid state so as to produce desirable properties or conditions. Imperatively, inasmuch as cast irons are concerned, are changes takes place on the material cooling from a point beyond that of the critical temperatures. Cast iron heating temperature prior to the start of cooling defines the stages which exist towards the beginning and end of the cooling process, while the form of such stages (the heat-treated cast iron microstructure) is determined by the rates and temperatures of the cooling. Magnesium Alloys One method of improving magnesium alloys strength is through grain refinement, an effective way of improving the Magnesium alloys mechanical properties. In this case, magnesium alloys having small grain size (nearly 1 mm) can be produced through equal channel angular extrusion (ECAE) procedure or through the powder metallurgy technique. Through relevant mass-production methods, an AZ91 alloy having10 mm grain size was achieved through casting ingots and subsequent hot extrusion. At high temperature it is difficult to attain a strong magnesium alloy through grains refining since .magnesium alloys usually have a fast rate of solid diffusion at high temperatures. Therefore, stable as well as fine particles must disperse uniformly in the matrix so as to ensure increased strength and high creep resistance. Another way of strengthening is through extension twins, which is normally used for toughening as well as strengthening of AZ31 magnesium alloy (hot-rolled) through extension twins during changed recompression of the strain path. In favorable conditions, extension twinning may take place in twins produced through pre-compression along the rolling direction. In view this, grain refinement through extension twins radically improves both peak stress as well as yield stress of reloading devoid of any elongation degradation, and the effect is correlated closely to the pre-strain level. Strong mechanical anisotropy is exhibited by magnesium alloys having a basal texture. Basically, under compression along transverse direction as well as rolling direction, initial plastic deformation is dominated by the extension twinning resulting in relatively low yield stresses along transverse direction and. It has been confirmed lately that utilization of precompression so as to introduce twins along hot-rolled AZ31 magnesium alloy rolling direction has led to both the ultimate strength as well as the yield strength under recompression along transverse direction being improved dramatically with the elongation increasing to some extent [38]. Evidently, extension twins produced by pre-straining can toughen as well as strengthen textured magnesium alloys along certain directions such as transverse direction and rolling directions. Yang and Koo investigated mechanical properties as well as microstructure of magnesium alloy containing gadolinium, yttrium and zirconium in a series of tempers, which included extruded-T5, cast-T6, cast-T4 and as-cast conditions [39]. They noted that effective grain refinement is achieved through hot extrusion with a small ratio of extrusion and a combination of sufficient ductility as well as high strength at room temperature was realised for cast-T6 alloy through optimisation of heat treatment parameters together with the extruded-T5 alloy extrusion at 400°C had elongations, tensile yield strengths and ultimate tensile strengths of 4.7 per cent, 239 and 362 mega Pascal as well as 15.3 per cent, and 311 and 403 mega Pascal, in that order. Furthermore, continual elongation increase results in the decrease of strengths between room temperature and 200 degrees Celsius [40]. Strengthening because of precipitation as observed by Yang and Koo contributes largely to alloy strength, either in extruded-T5 condition or cast-T6 condition and the strengthening of the grain boundary as well contributes considerably subsequent to hot extrusion [39]. Recycling issues and future developments (light weighting) of automotive engine block materials Aluminium alloys Presently, there are numerous comprehensive challenges with regard to production of aluminum alloys from recycled metal. Apart from the recycled beverage cans, the majority of the recycled aluminum has a mixture of alloys from different applications, which includes a castings selection having somewhat high proportions of silicon. Even though recycling aluminum alloy castings is not an issue, the challenge arises in shredding, sorting, as well as refinement of the aluminum alloy so as to get products’ impurity levels that are acceptable other than castings, which includes plate, sheet, extrusions as well as forgings. The majority of aluminum alloys used nowadays needs very close-fitting composition controls on both silicon and iron; therefore, impurity levels above 0.15 to 0.25 per cent silicon or 0.10-0.15 per cent iron are intolerable, especially in high toughness aluminum alloys. In high-performance automotive alloys Fe and Si are restricted to 0.40 per cent maximum, and both elements are hard to control in aluminum alloys recycling, and are inclined to increase self-effacingly when the metal is recycled many times. The future of aluminum alloys is very promising due to their impressive yet underused potential. Aluminium alloys as engine blocks materials have the potential to make significant as well as further contributions in the effort of reducing global consumption of energy. Their light weighting benefits of aluminium alloys are evident and a number of automotive industry collaborations are making efforts to expand their applications in the future industrial efforts. Cast iron With regard to economics of recycling cast iron, it is evident that recycled cast iron brings about composition problems. Akin to aluminium alloys, issues in cast iron recycling are attributed to the fact that the recycled metal with have unneeded impurities making them less effective for making engine blocks. Whereas the aluminium prices are falling continually, countries like Austria that produce iron ore will be the biggest earner. Even though the slowing Chinese economy and the Greek crisis has resulted in the 10 per cent decrease in the prices of iron ore price, the future of cast iron in making engine blocks is still strong. But increased use of aluminium alloys and magnesium alloys due to their light weight will result in reduced use of cast irons. Magnesium alloys As indicated above, die casting is a technique used for fabrication of magnesium alloy parts, scrap from die casting foundries may be managed in a number of ways. For instance, the scrap may be downgraded for utilization in the steel desulphurization or be sold in other markets. Foundries are sometimes utilized for recycling magnesium scrap either externally or internally, and this technique is considered cost effective way of managing scrap quantities. In this case, the process scrap generated during die casting is maintained in the closed loop system; thus, reducing primary material demand by almost 50 per cent. Basically, there are a number of factors dictating the quantity of processed scrap, which is produced as well as recycled in addition to the quantity of primary metal used. The efficiency of recycling operation has an effect on amount of primary magnesium and process scrap used. Similarly to aluminum alloys, the future of magnesium alloys in production of engine blocks is very promising. Magnesium alloys are preferred by manufacturers because they are lightweight material and have a density that is 30% less than aluminium. The ease of recycling magnesium alloys will in future make them more environmentally friendly substitute for cast iron and aluminium alloys for engine block material. Bibliography 1. Mark Z. Jacobson, Atmospheric Pollution: History, Science, and Regulation. Cambridge : Cambridge University Press, 2002. 2. Hieu Nguyen, "Manufacturing Processes and Engineering Materials Used in Automotive Engine Blocks," Grand Valley State University, Grand Rapids, Michigan , Term Paper 2005. 3. Dr. Steve Dawson, "Compacted Graphite Iron: Mechanical and Physical Properties for Engine Design," SinterCast, Dresden, 1999. 4. S. Miller et al., "Recent development in aluminium alloys for the automotive industry," Materials Science and Engineering, vol. 280, pp. 37–49, 2000. 5. B.P. Bhardwaj, The Complete Book on Production of Automobile Components & Allied Products. Kamla Nagar, Delhi : Niir Project Consultancy Services, 2012. 6. Musfirah A.H and Jaharah A.G, "Magnesium and Aluminum Alloys in Automotive Industry," Journal of Applied Sciences Research. 2012, vol. 8, no. 9, pp. 4865-4875. 7. J. Gilbert Kaufman, Introduction to Aluminum Alloys and Tempers. Novelty, OH : ASM International, 2000. 8. Jürgen Hirsch, Birgit Skrotzki, and Günter Gottstein, Aluminium Alloys: The Physical and Mechanical Properties. New York: John Wiley & Sons, 2008, vol. I. 9. F. Ozturk and S. Kilic S. Toros, "Evaluation of tensile properties of 5052 type aluminum-magnesium alloy at warm temperatures," International Scientific Journal. 2008, vol. 34, no. 3, pp. 95-98. 10. M. M. Avedesian and Hugh Baker, ASM Specialty Handbook: Magnesium and Magnesium Alloys. Novelty, OH : ASM International, 1999. 11. Janina M. Radzikowska, "Metallography and Microstructures of Cast Iron," in Metallography and Microstructures. Materials Park, Ohio: ASM International, 2009, vol. 9, pp. 565-587. 12. G.S.Cho, K.H.Choe, K.W.Lee, and A.Ikenaga, "Effects of Alloying Elements on the Microstructures and Mechanical Properties of Heavy Section Ductile Cast Iron," Journal of Materials Science & Technology. 2007, vol. 23, no. 1, pp. 97-101. 13. Bijender Singh and Manoj Kumar Agarwal, "RESEARCH OF CAST IRON IN ACIDIC MEDIUM IN THE INDUSTRIAL FIELD AS COMPONENTS IN ACID PICKLING," International Journal of Research in Science And Technology. 2011, vol. 1, no. 1, pp. 1-8. 14. Peter Metcalfe and Roger Metcalfe, Engineering Studies. Brisbane City: Pascal Press, 2006. 15. Karl-Heinrich Grote and Erik K. Antonsson, Springer Handbook of Mechanical Engineering. New York: Springer Science & Business Media, 2009, vol. 10. 16. LTC GmbH. (2011) Magnesium Alloys. [Online]. http://www.ltc-gmbh.at/en-us/scopeofservices/magnesiumthixomoding%C2%AE/material.aspx 17. L. Čížek et al., "Mechanical properties of magnesium alloy AZ91 at elevated temperatures," Journal of Achievements in Materials and Manufacturing Engineering. 2006, vol. 18, no. 1-2, pp. 203-306. 18. Christoph Schmitz, Handbook of Aluminium Recycling. Essen: Vulkan-Verlag GmbH, 2006. 19. Efthymios Balomenos, Dimitrios Panias, Ioannis Paspaliaris, Bernd Friedrich, and Benjamin Jaroni, "Carbothermic Reduction of Alumina: A Review of Developed Processes and Novel Concepts," in Proceedings of EMC 2011 729, Villigen, Switzerland, 2011, pp. 729-744. 20. Raymond Fernandes, Chemistry 10. New Delhi, Delhi : Ratna Sagar, 2010. 21. P. Fitzgerald and G. French, "THE PRODUCTION OF ALUMINIUM," N.Z. Aluminium Smelters Ltd, Tiwai Point, New Zealand, Working Paper 2009. 22. Eugene Avallone, Theodore Baumeister, and Ali Sadegh, Marks' Standard Handbook for Mechanical Engineers. New York, NY: McGraw Hill Professional, 2006. 23. H S Bawa, Manufacturing Processes. Delhi: Tata McGraw-Hill Education, 2004. 24. Chris Hughes, Desing and Technology: Resistant Materials. London , Letts and Lonsdale, 2002. 25. Kaveh Edalati Farshad Akhlaghi Farshad Akhlaghi, Mahmoud Nili-Ahmadabadi, and Mahmoud Nili-Ahmadabadi, "Influence of SiC and FeSi addition on the characteristics of gray cast iron melts poured at different temperatures," Journal of Materials Processing Technology. 2005, vol. 160, pp. 183–187. 26. B. Ravi, METAL CASTING: COMPUTER-AIDED DESIGN AND ANALYSIS. Delhi: PHI Learning Pvt. Ltd, 2005. 27. Hisao Watarai, "rend of Research and Development for Magnesium Alloys — Reducing the Weight of Structural Materials in Motor Vehicles," Quarterly Review. 2005, no. 18, pp. 84-97. 28. Artikel. (2003) Production, properties and industrial uses of magnesium and its alloys. [Online]. www.keytometals.com/Print.aspx?id=CheckArticle&site=ktn&LN=NL&NM=68 29. Geoffrey Davies, Materials for Automobile Bodies. Oxford: Butterworth-Heinemann, 2003. 30. K. U. Kainer, Magnesium alloys and their applications. Frankfurt: Wiley-VCH, 2000. 31. Øyvind Ryen, Hans Ivar Laukli, Bjørn Holmedal, and Erik Nes, "Large strain work hardening of aluminum alloys and the effect of mg in solid solution," Metallurgical and Materials Transactions A, 2006, vol. 37, no. 6, pp. 2007-2013. 32. John Gilbert Kaufman and Elwin L. Rooy, Aluminum Alloy Castings: Properties, Processes, and Applications. Novelty, OH: ASM International, 2004. 33. Joseph R. Davis, Aluminum and Aluminum Alloys. Novelty, OH : ASM International, 1993. 34. Roger N. Lumley, Allan J. Morton, Robert G. O’Donnell, and Ian J. Polmear, "NEW HEAT TREATMENTS FOR AGE-HARDENABLE ALUMINUM ALLOYS," Heat Treating Progress, 2005, pp. 23-29. 35. F.J. Humphreys and M. Hatherly, Recrystallization and Related Annealing Phenomena. London: Elsevier, 2012. 36. Von L. Richards and Wayne Nicola, "FINAL TECHNICAL REPORT: AGE STRENGTHENING OF GRAY CAST IRON PHASE III," University of Missouri Rolla, Warsaw, IN, 2003. 37. John Lancaster, Handbook of Structural Welding: Processes, Materials and Methods Used in the Welding of Major Structures, Pipelines and Process Plant. Sawston, Cambridge : Woodhead Publishing, 1997. 38. X. Li, W. Qi, K. Zheng, and N. Zhou, "Enhanced strength and ductility of Mg–Gd–Y–Zr alloys by secondary extrusion," Journal of Magnesium and Alloys. 2012, vol. 1, no. 1, pp. 54–63. 39. Wan-Gye Yang and Chun-Hao Koo, "Tensile Properties of Mg–8Al–xRE Alloys from 300K to 673K," Materials Transactions. 2003, vol. 44, no. 5, pp. 1029 -1035. 40. Shangming He et al., "Microstructure and strengthening mechanism of high strength Mg-10Gd-2Y-0.5Zr alloy," Journal of Alloys and Compounds. 2007, vol. 427, no. 1-2, pp. 316-323. x Read More