'Verification of Heat Treatments Effect on the Microstructure of Aluminum Alloy (Al-Zn)\r'

' curb OF HEAT TREATMENTS EFFECT ON THE MICROSTRUCTURE OF ALUMINUM subvert (Al-Zn) *1 I. A. LATEEF, and 2 M. O. DUROWOJU 1Department of Mechanical Engineering, Osun State College of Technology, P. M. B. 1011, Esa †Oke, Nigeria. [email&# nonpargonil hundred sixty;protected] com 2Department of Mechanical Engineering, Ladoke Akintola University of Technology, Ogbomoso, Oyo,State, Nigeria *(Address of correspondence) ABSTRACT: This field of operations foc employ on the launch of rut treatment on the micro twist of atomic number 13 †Zinc vitiate.\r\nThe composition of the Aluminum debasement employ is eighty percent (80%) of Aluminum and twenty percent (20%) of Zinc. The manner of dramatis personae employed is suave casting, musical composition annealing and decimateing were fire up treatment processes it’s subjected to. The micro social system is interpreted. It is concluded that rut treatment have effect on the microstructure of Aluminum †Zinc di lute and responded hearty to vegetable oil allay. [Keywords: Aluminum-Zinc Alloy, fondness treatment, Microstructure, Tensile test, Hardness test, normalize and Water quenching. INTRODUCTION The extensive application of metals in the field of Engineering has necessitated the need for metal heat treatments in clubhouse to meet the taste of firm, industries and single as a result of their wide applied experience application. One of the major(ip) engineering fields where the application of various metals was employ is Automobile engineering. In order to reduce motor vehicle weight, galore(postnominal) self-propelling components have been redesigned to take advantage of material much(prenominal) as lightweight and polymers.\r\nTo this end aluminum casting alloys atomic number 18 being widely utilise for numerous automotive components (CAD, 2006), the alloys have good casting characteristics, intelligent mechanical properties, and atomic number 18 heat treatable (Melo, Rizzo and Santos, 2005). Material science and engineering today has developed to a fix up where correlations amongst microstructure, properties and application base be naturalised for many commonly used alloys.\r\nThe structure of a material is related to its composition, properties, touch on history and surgical operation (Argo and Gruziesk,(1988) and Rooy,(1993)). And therefore, studying the microstructure of aluminum alloys provides information linking its composition and processing to its properties and performance interpretation of microstructure requires the understanding of the process by which various structures ar formed. There are many processes by which aluminum alloys digest be formed.\r\nThe major process that is common and the focus of this study is the Sand casting process (Albert, (1957)). One of the common defects in aluminum castings is porosity (Monroe, (2005) and Tyler, 1981)). It is a clear accompaniment that the quantity and the appearance of the poros ity are very(prenominal) crucial to the mechanical properties of the aluminum alloy casting, close especially the fatigue properties because the pore in micro scale are primary source of sign cracks for the final failure of the aluminum parts.\r\nDue to this the aluminum alloys structure need to be improved by metal treatment to have the required properties. Olanrewaju (2000), state that metal treatments are classified into two groups namely-: awake treatment and sur gift treatment. Surface treatment as corrosion resistance operations includes phosphating chroming nickeling, anodization and so on, magical spell heat treatment as structural adjustor includes hardening, tempering toughening and so on (Ojediran and Alamu, (2004) and Vincet,(1968)).\r\nIn this study, the do of such heat treatment are mulish to know the extent of their impact on the aluminum †Zinc alloys (Al- Zn). MATERIAL AND EXPERIMENTAL TECHNIQUES Materials used The targeted materials composition, uses a nd forms are as follows: TABLE 1 THE COMPOSITION, USES AND FORMS OF ALUMINUM ALLOYS | fundamental law | Uses | Forms | |Al †Zn 20% |Ar mored vehicle, military machine | Rod (10mm x 150 mm) | | bridge, bicycle and | | | | rack frames, | | | |Air frames etc | | Equipments used The following equipments were used for the study: Pit furnace, Sand mould, Electrical furnace, and Crucible Pots at FIIRO, Nigeria. And Mosanto Tensometer, Wild metallurgical Micros pull off, Polishing Machine,and Manual rubbing Machine at Obafemi Awolowo University, Ile-Ife, Nigeria.\r\nOthers are-Digital Cameral, Patterns, Grit papers, Emery Cloth/Paper, silicon carbide solution of different grade and NaOH Solution Methods form Process A Crucible pots is used, 1 kg of commercial purity Aluminum (99. 7 % exquisite by weight) and 250g of Zinc is used. The alloying subdivision Zn is drop low gear in the Pot because of its high melt point (1108oc) which is higher than that of the base metal atomic n umber 13 (660oc). So, the Zinc (Zn) in the pot is lowered first into the furnace epoch the aluminium is added after Zn has commenced melting.\r\nThe corporation of for each one of the alloying ingredients used for each savor canister be obtained as follows: Total mass of diverseness for the take ins= frames Mass of Al + Mass of alloying piece = 1kg + 0. 250kg = 1. 250kg component of Aluminum (Al) in the mixture = mass of Al/Total mass x coke =1/1. 250 x 100 = 80% Percentage of alloying element (Zn) = Mass of alloying element/Total mass x 100 =0. 25 / 1. 50 x 100 = 20% The dimension of one exemplar is as following: Height of the sample =150mm (15cm) Diameter of the sample = 12 mm (1. 2 cm) Radius of the sample =60mm (0. 6cm) Shape of the sample= Cylindrical Volume of the sample (V) =? r2h = 3. 142 x (0. 6) 2 x 13 = 16. 96 cm3 Density of Aluminum = 2. 69g/cm2 (Olagoke, 1999). Mass of sample used = ? x V = 2. 69 x 16. 96 = 45. 64 g Therefore, 80 % of Aluminum = 36. 51 g f or each sample Also, 20% of Alloying element (Zn)= 9. 13 g For each sample (rod form) 36. 51 g Al + 9. 13 g of alloying element (Zn) were used.\r\nThe samples for heat treatment are: Sample 1 =as accredited from Casting process. Sample 2 = for quenching in Water. Sample 3 = for Oil quench Sample 4 = for annealing (Furnace cool). The regularity adopted in casting the samples is sense molding (Sand casting). The casting process is performed at FIIRO Nigeria Limited, Lagos. The pattern is do from wood with the following dimensions Height †15 cm Diameter †1. 2 cm The sand used is the traditional-green sand’ which is a mixture of sand grains and body particles, clean sand with oil and binders).\r\nThe mould used is a conventional vertical sand mould. The go after is set(p) elevation down on a firm flat surface and the pattern is placed face down and pattern is placed face down and then, dusted with a parting powder. Handfuls of sifted sand are then thrown at the pattern, covering either detail (Sand slinging). The sand is rammed. The drag is turned upside down with a swift movement. The cope is fitted onto the drag. The cope is rammed with sand and strictly making the top smooth and firm. And the cope is removed.\r\nThe crucible is held about half sort down with tongs and withdrawal from he furnace. impureness is raked away from pouring lip with heated sailor and the metal poured in one continuous pullulate until it appears at the head of the riser. When the casting has solidified and cooled, the sand is knocked out and the casting fettled. Heat treatments process Heat treatment is also carried out at FIIRO Nigeria limited, Lagos. The types of heat treatment carried out are: Annealing and slakeing. common chord each of Al-Zn casting samples were put in the galvanising furnace (up to 3300oc).\r\nThe soaking time for the sample in the furnace is one hour, after which two of the Al-Zn casting samples is removed and quench in both water and oil magic spell the last one of Al-Zn is allowed to cool in the furnace air (annealing). Microstructure Analysis Process. The microstructure was done at Obafemi Awolowo University, Ile-Ife, Osun State. The samples were machined and grounded to gauge 240, 320, 400, 600 each using Grinding Machine and Grit paper. severally sample is initially polished, using Polishing machine, emery stuff and Silicon Carbide.\r\nThe final polishing is done with the attending of Polishing machine, Emery cloth and Silicon carbide of different grades while scratching took effect using 5% NaOH Solution. individually sample is examined using the Optical Microscope to check that etch reveal clearly the Microstructure of the sample. The photograph of the resulting microstructure of the aluminum-Zinc (Al- Zn) alloy samples were taken using Optical microscope with x100 magnification and Digital Cameral. RESULTS AND news Discussion on the Microstructure Results of Al- Zn Alloys. The figure 2 benea th shows the microstructure of Al-Zn alloy, As veritable sample i. without heat treatment. It can be observed that the grains were not homogenized and pores are numerous towards the peripheral zone encrypt 2 Microstructure of As Received; Al †Zn alloy Sample 1. The figure 3 below shows the microstructure of Al â€Zn alloy, Oil quenched sample. It can be observed that the grains are more equal and well distributed towards the core. The pores are not numerous comparing to Al- Cu alloy, As received sample. Figure 3 Microstructure of Oil Quench; Al †Zn Alloy Sample 3.. Figure 4 below shows the microstructure of Al- Cu alloy, Furnace cooled sample.\r\nIt can be observed that the grains were deformed at peripheral more than at the core of the structure and there are more pores than that of As received sample and Oil quenched sample. this indicates that there is no significant improvement in the microstructure arrangement of grains when Al-Cu alloy is oil quenched Figure 4 Microstructure of Furnace Cooled; Al †Zn Alloy Sample 4. Figure 5 below shows the microstructure of Al- Zn alloy, Water quenched sample. It can be observed that the grains were deformed throughout the structure and there are more pores than that of As received sample and Oil quenched sample.\r\nThis indicates that there is no significant improvement in the microstructure arrangement of grains when Al-Zn alloy is Water quenched. Figure 5 Microstructure of Water Quench; Al †Zn Alloy Sample 2. . decision From the result of the experiments, it can be deduced that: (i) The arrangement of the microstructure grains and pores are more even with the Oil quench method than any other heat treatment methods in Al †Zn alloy. (ii) There is relationship between the heat treatments method (Oil quench) and microstructure of Al- Zn alloy. iii) Oil quench Aluminium Zinc alloy (Al †Zn ) is more appropriate for the production of Armored vehicle, Military bridge, Motorcycle frames a nd Bicycle frames and Air frames ACKNOWLEDGEMENT The workers of FIIRO Nigeria limited,Lagos and Mr Alo of Metallurgy and Material Department, Obafemi Awolowo University Ile- Ife, Osun State, Nigeria are acknowledge for providing the facilities for this research work. REFERENCES Ojediran, J. O. and Alamu, O. J. (2005) Fundamental concepts in Materials recognition and Engineering; Kunle (Nig) Printers; Ijebu-Ode, Nigeria.\r\nVol. 1, 1st ed, pp. 46. Vincet, A. (1968) Workshop Theory for G. C. E. metalworking and Engineering; Macmillan, 2ed, pp. 11- 14. Olagoke, S. A. (1999) Properties of Materials; Rosad and Company, Ibadan, 1st ed, pp. 210 †211. Tyler, H. A. (1981) Science and Materials (Level iii); Van Nostrand Reinhold Limited, Australia,1st ed, pp. one hundred seventy Copper Development Association (CAD 2006) Standards and Properties †Microstructure of copper alloys Albert P. G. (1957) The basic principle of Iron and Steel castings; The international Nickel Company, Inc . U. S. A. , pp. 11 Melo, M. L. N. , Rizzo, E. M. S. and Santos, R. G. 2005) Numeral Simulation Application in Microporosity prevision in Aluminum alloy castings; Revisa Brasileira Applicacoes de Vacuo, vol. 24, pp. 36-40. Monroe, R. (2005) Porosity in casting; Schaumburg, USA, Siver Anniversary Paper, Division 4,American Foundry Society. pp. 1 †28. ASM Metals Handbook,(1988); 9ed, Vol. 15, Casting, ASM Rooy, E. E. (1993) Hydrogen: The one- third Solution AFS Transactions, Vol. 101, and PP. 961 †964. Argo, D. and Gruzleski J. E. (1988) Porosity in Modified Aluminum alloy Castings, AFST Transactions, Vol. 96, and pp. 65 †73. ———————†[pic] [pic] [pic] [pic]\r\n'