EXPERIMENTAL INVESTIGATION OF THE ALUMINIUM -SILICON ALLOYS AZIZA SHEYI OKIEMUTE EM

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1 EXPERIMENTAL INVESTIGATION OF THE MECHANICAL & MICROSTRUCTURAL PROPERTIESOF ALUMINIUM -SILICON ALLOYS BY AZIZA SHEYI OKIEMUTE EM DEPARTMENT OF MECHANICAL ENGINEERING, SC.HOOL OF J:NCINJ:J:RINC AND J:NCINJ:J:RlNC TECHNOLOGY, FEDERAL UNIVERSITY OF TECHNOLOGY MINNA MINNA, NIGER STATE, NIGERIA NOVEMBER 2007

2 EXPERIMENTAL INVESTIGATION OF THE MECHANICAL AND MICROSTRUCTURAL PROPERTIES OF ALUMINIUM SILICON ALLOYS BY AZIZA SHEYI OKIEMUTE 2001J12202EM A PROJECT SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE A WARD OF BACHELOR OF ENGINEERING (B. ENG) IN MECHANICAL ENGINEERING TO THE DEPARTMENT OF MECHANICAL ENGINEERING IN THE SCHOOL OF ENGINEERING AND ENGINEERING TECHNOLOGY, FEDERAL UNIVERSITY OF TECHNOLOGY MINNA NIGER STATE, NIGERIA NOVEMBER

3 CERTIFICATION This is to certify that this thesis "Mechanical and Micro structural Properties of Aluminium-Silicon Alloys" was written by AZIZA SHEYIOKEIMUTE ( EM) in the department of Mechanical Engineering of the Federal University of Technology Minna under the supervision ofengr S. Abdulrahman. It is in partial fulfillment of the requirement for the award of Bachelor of Engineering (B.Eng.) Degree in mechanical Engr. S. Abdulrahman Project supervisor ~~I/ll~ Signature and date Dr E Mudiare H.O.D Mechanical Engineering Signature and date External examiner Signature and date 1ll

4 DECLARATION I dcclare.th<lt this research work "Mechanical and Micro<; flllctuf(li Pf( 'I 'f' rti es of Aluminiulll -- Si licon <lfloys" was entirely carried out by" Aziza Sh eyi OkeimIl1c" (2001 / 12202EM) under th e supervision ofengr. Salawu Abdllll :1 hm<l1l AZ IZA SHEYI OK EIMUTIE IV

5 DEDICATION This project is dedicated to the Almighty God, the omniscience and omnipotent ' VflO has heen our help and anchor. To him alone we give all the Glory. v

6 ACKNOWLEDGEMENT I give thanks to the almighty God, the creator of the world, and th e f"<lther of all ll (ltinl1<; For hi s love, guidance,mercy, protection, provisions,support. and hlessin gs upon my life.. Glory be to God in Jesus name Amen. My sincere thanks goes to Dr.E. Mudiere and Engr.S.Ahdulrl'lhman for th l' lr fath erly and profess ional advice, and priceless contribution, without whi ch this study I'ould have been imposslhl e. My si nce~e, profound, and unreserved gratitude also goes to my pments Mr. an d Mrs. P. N Aziza, and a special thanks to my darling mother, for her Il1Pnll. 1"1 - miti gated lo ve, she has shown towards me, may God continue to bless you in Jesus Il(lrne Am en., My sincere appreciation goes to my lovely sisters, m~rn(l.i and hcoii for "II th e' love. support and understandin g., you have shown me over th e years, may God in his infinite mercies continue to guide, protect, and enrich you in Jesus IHlllle' Amen. M' wonderful aunts and uncles aunt iyabo and aunt mulika thanks for all your motherly love Iny cousins Kola,Kato, Kike, I)umex, Shefo, Busola Busayo Hakeem, lukmall, Afeez Ml riam Taye and Kehind e and those i cannot remember. To my lovely girl fi"iend Hali l. thanks for being there for me, ob~tie men Bishop, Maro pumping, doncln ktg onor'. chairmo, muchacho. Sammy God be with all of you and see you through your futur r endevours Amen Most of al l I'll like to thank my Grandma Alhaja SifawII Adewuyi to r all your praye rs and love. Thank you rna VI

7 ABSTRACT In the field of engineering especially in the autolllohile c:cctor. en! ~1I 1e piston. engine hlock and other intricate parts of the engine are produced.1\ 1- si alloy, ::I re one of (he most widely lised alloys. This is because of th eir li llhl weight In streng1h characteristics. This research work was designed to vary th e composition of Ihe silicon from alloy element with aluminum for better ductility, castability and reduc 'd tendency to create or bottle fracture. Also to increase the hardness.and ensure a maxinli lm energy of the sample Eight sa mple were produced out of which four were heat treated (solution heat treatment and natural age hardening). The compositions of til e alloys ar E' "iample ;\; Al 93.1% Si 4.4% Fe~ %, Sample B; Al 90.0% Si 6.8% Pe 2.2 fi / O. Sampl e (' \I 9'i% Si 2.8% Fe 2.2%. Sample C ;;\1 95% Si 2.8% Pe 2.2%. Aft er which th e salllple" wrre 'subjected to mechanical test (tensile, impact, hardness) and mi Cl(l<;('opic ob c;"rvation to reveal the soundness of the cast alloys. The results are as shown ill (' hapter 4. Vlll

8 TABLE OF CONTENTS Certification Declaration Dedication Acknowledgement Abstract Table of contents List of tables List of figures III IV V VI VIII IX XII xi;; CHAPTER ONE Introduction General background A ims and Objectives Just; fication of project 3 4 CHAPTER TWO I I Literature Review History and Present State of Aluminium Production Extract ion of Aluminum Important Physical Properties Atomic Structure IX

9 2.3.2 Crystal Structure Den si ty Electrical Conductivity and Resistivity Thermal Conductivity II Corrosion Resistance l] Thermal Expansion '.8 Melting Temperature Specific Latent Heats /\IIoys of /\!'umirlllm Classification of AI-Alloys 1() 2.5 Mechanical Properties of AI-Alloys Uses of /\luminum and the Alloys 26 CHAPTER THREE 3.0 Ex perimental Procedure Sample Collection and preparation. 2R 3.2 lleat Treatment of Sample Mechan ical Test on Samples Impact Test Hardness Test ) Tensi Ie Test Metallographic Observation Sample Selection.and preparation Mounting of the Specimen 35 x

10 3.4.3 Grinding and Polishing 36,3.4.4 Etching Metallurgical Microscope Observation Photomicrography 37 CHAPTER FOUR +.0 Result and Discussion 39 4, I Notch bar ImpacfTest Result :W 4,2 Hardness Test Result Tensile Test Result Meta Ilograph ic Observation Discussion of Result Impact Test Result 4() 4, 5.2 Hardness Test Result Tensile Test Result Micrograph Interpretation 47, 4. 7 Effect of i\geing on The AI-Si Alloys. 48 CHAPTER FIVE ),0 Recommendation and Conclusion Summary of Findings Recommendation Conclusion 51 REFERENCES APPENDIX XI

11 LIST OF TABLES Table 2.0 I\luminium alloy Description (Wrought Alloys) T'able 2.1 Aluminium alloy Description (Casting Alloys) 17 Table 2.2 Mechanical Properti es of Aluniinium Table 3.1 Composition of Alloy Samples Table 4.0 Notch bar Impact Test Results Table 4.1 Hardness T est Results (As-Cast) Table 4.2 Hardness Test Results (Heat Treated) Table 4.3 Tensile Test Results (As-Cast) Table 4.4 Tensile Test Results (Heat Treated) XII

12 LIST OF FIGURES. Fig 1.1 AI-Si phase diagram Fig 2.1 Atomic structure of Aluminium rig' 2.2 Crystal structure of,aluminium 10 Fi g 2.3 Thermal conductivity of Aluminium Compared with other metals 12 Fig 2.4 Thermal conductivity of Aluminium Compared in terms of weight with other metals Fig 2.5 AI-Cu phase diagram Fig 2.6 AI-Mn phase diagram ~ig 2.7 AI-Si phase diagram Fig 2.8 AI-Mg phase diagram Fig 2.9 AI-MgSi phase diagram Fig 3.1 Impact test sample Fig 4.0 Sample A (as cast) Fig 4.1 Sample A (HT) Fig 4.2 Sample B (as cast). Fig 4.3 Sample B (HT) Fig 4.4 Sample C (a<; cast) Fig 4.5 Sample C (I IT) Fig 4.6 Sample D (as east) Fig 4.7 Sample 0 (I IT) 12 IR n