INVESTIGATION OF MECHANICAL PROPERTIES IN ALUMINIUM SILICON CARBIDE MICA HYBRID METAL MATRIX COMPOSITE

Transcription

1 INVESTIGATION OF MECHANICAL PROPERTIES IN ALUMINIUM SILICON CARBIDE MICA HYBRID METAL MATRIX COMPOSITE P Saravanan 1, M Shanmuga Priyan 2, R Raghuram 3, S Sharath Kumar 4, T Anand 5 1 Student, Mechanical Engineering, SriMuthukumaran Institute f Technlgy, Tamil nadu, India, saravchanselvam@gmail.cm 2 Student, Mechanical Engineering, SriMuthukumaran Institute f Technlgy, Tamil nadu, India, glriussun.m21@gmail.cm 3 Student, Mechanical Engineering, SriMuthukumaran Institute f Technlgy, Tamil nadu, India, raghuramsmilecan@gmail.cm 4 Student, Mechanical Engineering, SriMuthukumaran Institute f Technlgy, Tamil nadu, India, sharathk69@gmail.cm 5 Assciate prfessr, Mechanical Engineering, SriMuthukumaran Institute f Technlgy, Tamil nadu, India, tanandresearch@gmail.cm Abstract The wide range f availability f aluminium has made it an imprtant material fr manufacturing many cmpnents. An aluminium ally which has lw tensile strength and hardness is been cmpsited with ther materials t imprve its prperties and reduce its drawbacks. Aluminium is been cmpsited with silicn carbide that drastically increases the prperties. Our study invlves fabricatin f aluminium silicn carbide with mica in stir casting methd t btain a hybrid metal matrix cmpsite. Maintaining a cnstant amunt f aluminium and silicn carbide, mica is varied t btain a three different cmpsitins f (AlSiCM) cmpsites. The mechanical prperties such tensile strength, flexural strength, impact and hardness are studied. The dispersin f mica and silicn carbide particles are bserved by viewing the micrstructure phtgraphs btained using Scanning Electrn Micrscpe (SEM). Index Terms: Aluminium metal matrix cmpsite, silicn carbide, mica, mechanical prperties, stir casting *** INTRODUCTION Aluminium is the third mst abundant material available in nature. It has replaced the ferrus element in wide range f applicatins due t its specific prperties like lw density, crrsin resistance due t passivatin, light in weight etc. Aluminium als has defective prperties which prevent it frm being applied in ther fields. In rder t vercme the defects f pure aluminium allys, a new material called aluminium cmpsite was discvered. Aluminium cmpsites are als called as aluminium metal matrix cmpsites. A metal matrix cmpsite is a cmbinatin f tw distinct metals t btain a cmpunded material knwn as reinfrced material. In metal matrix, matrix is the cntinuus material in which the reinfrcing material is added in whiskers, fabrics and particulates. The reinfrcement may be cntinuus r discntinuus. When mre than ne reinfrcement is added with the matrix it is said t be a Hybrid metal matrix cmpsite. The aluminium ally cmpnents are replaced with metal matrix aluminium cmpsites (MMC). The MMCs play a vital rle in ur mdern day tday life. Graphite r steel with high carbide cntents r tungsten carbides r metallic binders als cme under this categry. It is mainly used when a cnventinal material des nt achieve the required standards r specific demands. Reinfrcement f the metal matrix is chsen based n the required prperty t be achieved with a base metal. Such a MMC s are called as particulate metal matrix cmpsites (PMMCs). The PMMCs lead t btain a high strength and high wear resistive material by intrductin f hard particles such as silicn carbide, brn carbide etc.., Hybrid metal matrix cmpsites are mdern day cmpsites where mre than ne type f material f different shapes and sizes are used t imprve the prperties. They are still advantageus than PMMCs as it invlves with advantages mre than tw materials. Metal matrix cmpsites such as cbalt matrix with tungsten carbide particles is used t manufacture carbide drills, steel IJESAT Mar-Apr

2 reinfrced with brn nitride is used in tank armurs, in pwer electrnic mdules aluminium graphite cmpsites are used because f their high thermal cnductivity. These cmpsites have wide range f applicatin space systems because f their wide range f perating temperatures and resistance t absrb misture etc. [1]Anthny Macke, B.F. Schultz, PradeepRhatgi in their jurnal have described abut the pprtunity in reductin f weight and increase in perfrmance f aut mbiles using MMCs. [2]T.Rajmhan, K.Palanikumar, S.Ranganathan have discussed abut the mechanical and wear prperties f aluminium silicn carbide mica hybrid cmpsites and their results shwed that the mica cmpsite had gd strength and hardness. Cast aluminium ally cmpsites cntaining grund mica particles cated by cpper a jurnal published by [3]Dena T H, Rhatgi P K revealed that the grund mica cated with cpper fund t have gd strength and used fr bearing applicatins. 2. EXPERIMENTAL PROCEDURE 2.1 MATERIALS The matrix that has been used here is The ally cmpsitin and mechanical prperties f Al6061 is tabulated. A micrn size f 4μm black silicn carbide is used as the first reinfrcement and muscvite a type f mica f 26 μm is taken as the 2 nd reinfrcement. Three different cmpsitins, taking 1%, 2% and 3% f mica and 4% SiC as a cnstant required cmpsites are fabricated. The Table-1 shws the cmpsitin In which the material is fabricated. The fabricatin f cmpsites are dne by stir casting methd, Due t its suitability in prducing unifrmly distributed reinfrcements. Aluminium6061 was purchased in the frm f rds and then were cut int pieces t as per requirement f the crucible. Muscvite a type f mica was btained fr study frm Micafab industries. Table -2&3 shws the cmpsitin f Al6061 ally and its mechanical prperties respectively. Table-1: Cmpsitins f AlSiC-Mica COMPOSITIONS SiC % Mica % Table-2: Cmpsitin f Al6061 Cu Si Mg Mn Fe Ti Zn Al Max 0.15 Max0.7 Max0.15 Max 0.25 Bal Table-3: Chemical prperties f mica (mass fractin %) SiO2 Al2O3 K20 Fe2O3 Na2O TiO2 CaO MgO Traces Table-4: Mechanical prperties f Al6061 Density Elngatin gcm-3 % Ultimate Tensile strength MPa Yield tensile strength MPa Mdulus f elasticity Gpa Pissn rati Metallic mulds f required shapes are used t btain the specimens fr tests. The mlten metal f aluminium btained by stir casting is pured int the mulds. 2.2 SPECIMEN FABRICATION The cylindrical rds are cut int required sizes and placed int the crucible. SiC and Mica are taken in separate vessels and preheated alng with the crucible in the furnace up t a temperature f 850 C. The metallic mulds f required shapes are placed in the preheated and heated up t a temperature f 500 C. After 850 C is reached the mlten aluminium is taken ut and 5 grams f degasser is added t remve the impurities and small amunt f cverall is added t prevent xidatin. Fr a gd wettability a small amunt f magnesium is added. The heated SiC and Mica are added t the crucible and placed again int the furnace. The furnace is nce again heated up t a temperature f 850 C. The crucible is placed perpendicular t the stirrer and the stirrer is inserted int the crucible. The stirrer is made t stir at a speed f 300 rpm. The preheated metal mulds are placed ver river sand. The crucible with melt is pured int the muld. The melt is pured until the metal rises frm the riser. The muld is then allwed t cled and then the metal f the muld shape is btained which is then later cut int require dimensins f the specimen. 2.3 SPECIMEN TESTING TENSILE Tensile strength is ne f the imprtant parameters which is used t determine the applicatins f a material. Fig-1: Tensile test specimen The ASTM standard that has been applied fr tensile test is E8. The cylindrical rd casted by stir casting methd is IJESAT Mar-Apr

3 machined with respect t standard. A dumbbell shaped specimen was fixed at the ends f the universal testing machine. Tensile lad was applied until the break pint and the crrespnding values were recrded FLEXURAL Fr flexural testing, rectangular specimen was casted which was later machined int standard specimen. The specimen was placed ver the universal testing machine and then a vertical lad is applied until breakeven pint and the value are recrded. Fig-4:Hardness test specimen SEM SPECIMEN Fig-2: Flexural test specimen IMPACT The methd f impact test that has been applied here is charpy impact test. A standard test piece f required dimensin is machined and then the test was carried ut. Fig-5:SEM specimen Scanning Electrn Micrscpy (SEM) is the device used t view the particles and grain size f the specimen. The specimen is prepared by plishing 10*10*10 mm cube. 5% f vlume f HF etchant is used t etch the surface f the sample and it is washed in distilled water befre carrying ut SEM. 3. RESULTS AND DISCUSSIONS 3.1 MICROSTRUCTURE Fig-3:Impact test specimen HARDNESS The micrgraphs btained by scanning electrn micrscpy shw the dispersin f the reinfrcement particles in the matrix. The SiC particles were evenly distributed and mica was clgged at sme places. There is an agglmeratin f particles. Appearances f small pits are due t xidatin f surface by the etchants r may be by the grinding f the surface. Thread like grain bundaries are due t fine particles f reinfrcements added with matrix. Brinell hardness test was carried ut with a finely plished plate surfce. The surface was placed belw diamnd indentr and three sets f impressins were made and n a average the Brinell Hardness Number (BHN) was btained Fig-6:SEM micrgraph f Mica 1% cmpsitin IJESAT Mar-Apr

4 Fig-7:SEM micrgraph f Mica 2% cmpsitin The hardness result btained by Brinell Hardness Test shws that the cmpsitin with 2% f mica has a higher hardness than ther tw cmpsitins. It shws that n increasing mica, the hardness f aluminium silicn carbide decreases. As the decrease in hardness imprves the machinability f the cmpsite, this prves mica a gd substitute fr AlSiC cmpsite as a hardness reducing agent. Mica will be a gd substitute fr graphite because f its ductile nature IMPACT Table-6: variatin f impact strength in each cmpsitin s.n cmpsitins Impact in jules 1 +mica(1%) mica(2%) Fig-8:SEM micrgraph f Mica 3% cmpsitin The SEM phtgraphs acts as evidence fr the prper distributin f silicn carbide and mica particle in the aluminium matrix. 3.2 MECHANICAL PROPERTIES HARDNESS Table-5: variatin f hardness in each cmpsitin s.n cmpsitins Hardness in HBW 1 +mica(1%) mica(2%) Three impressins were made n the specimen f each cmpsitin in different places s as t get the aggregate value f hardness f the sample mica(1%) Hardness in HBW +mica(2%) Graph-1: Hardness variatin in each cmpsitin Hardness in HBW mica(1%) Graph-2: Impact lad variatins in each cmpsitin The impact f the cmpsites btained thrugh charpy impact test shws that the tughness f the cmpsite decreases at first and then increases. The yield strength f the cmpsite decreases as the cmpsitin f mica increases TENSILE Impact in jules +mica(2%) Impact in jules Table-7: variatin f tensile prperties in each cmpsitin s.n cmpsitins Tensile strength Yield stress Elngatin in % in Mpa in Mpa 1 +mica(1%) mica(2%) The figure shws the relatinship between tensile strength, yield stress and elngatin percentage f the cmpsitins. The tensile strength specimen increases frm 1% f mica cmpsite t 2% f it. Abve 3% f mica the tensile strength is bserved t be decreased. This shws that 2% mica IJESAT Mar-Apr

5 cmpsitin is the threshld regin f Aluminium silicn carbide Mica cmpsite. The elngatin percentage f all the three cmpsitin remained cnstant.the cnsistency in elngatin percentage is due t cnstant silicn carbide 4%.The brittleness increse with in crese in SiC and there by it is bservable that 2% mica cnstituent is gd mica(1%) +mica(2%) Graph-3: Tensile prperties variatin in each cmpsitn FLEXURAL Tensile strength in Mpa Yield stress in Mpa Elngatin in % Table-8: variatin f flexural strength in each cmpsitin s.n cmpsitins Flexural lad in KN 1 +mica(1%) mica(2%) higher bending lad than the ther cmpsites. Therefre n increasing mica the bending lad gets decreased at greater difference at first and fllwed minimal differences. 3. CONCLUSION Aluminium reinfrced with silicn carbide is the vital cmpsite with less machinability. In rder t imprve the prperties f such a cmpsite varius materials are reinfrced by researchers arund the wrld. The abve results shw that mica culd be a gd substitute t sften the AlSiC cmpsite. It is bserved that fabricatin f Aluminium silicn carbide mica cmpsite can be dne using stir casting methd. The micrgraphs btained frm SEM prve that the dispersin reinfrcement particles are finer with stir casting methd. The grain bundaries shw the mixing f particles with little clusters f particles. The hardness f the cmpsitins first increases and then decreases with higher hardness in 2%mica cmpsitin. The tughness f the cmpsitin first decreases and then increases. The tensile strength f the cmpsitin increases frm 1% t 2% mica cmpsitin fllwed by a fall in 3% mica cmpsitin. The flexural lad fr bending first decrease fllwed by increase. The 2% cmpsitin f mica is the better reinfrcement that shwed a effective prperties mica(1%) Flexural lad in KN +mica(2%) Flexural lad in KN Graph-4: Flexural lad variatin in each cmpsitin The flexural test is made t knw the lad at which a material starts t bend. The figure shws that the 1% mica cmpsite 4. REFERENCES 1. Anthny Macke, B.F. Schultz, PradeepRhatgi. Metal Matrix Cmpsites Offer the Autmtive Industry an Opprtunity t Reduce Vehicle Weight, Imprve Perfrmance.ASM internatinal 2. Rajmhan T, Palanikumar K. Mdelling and analysis f perfrmance in drilling hybrid cmpsites [J]. The Jurnal f Advanced Manufacturing Technlgy, 2012, DOI: /s Dena T H, Rhatgi P K. Cast aluminium ally cmpsites cntaining cpper-cated grund mica particles [J]. Jurnal f Material Science, 1981, 16: Sngmene V, Balazinski M. Machinability f graphitic metal matrix cmpsites as a functin f reinfrcing particles.. Ann CIRP, 1999, 48: 77 8 IJESAT Mar-Apr

6 5. Dinesh Pargunde, Prf. DhanrajTambuskar, Swapnil S. Kulkarni. Fabricatin f metal matrix cmpsite by stir casting methd, Pargunde,etal, Internatinal Jurnal Of Advanced Engineering Research and Studies E-ISSN N. Barekar, S. Tzamtzis, B.K. Dhindaw, J. Patel, N. HariBabu,and Z. Fan.Prcessing f Aluminium-Graphite Particulate Metal Matrix Cmpsites by Advanced Shear Cmpsites-A Review, Internatinal Jurnal f Current Engineering and Technlgy ISSN GUAN Na, GENG Lin, ZHANG Hng-wei, HUANG Lujun. Effects f stirring parameters n micrstructure and tensile prperties f (ABOw+SiCp)/6061Al cmpsites fabricated by semi-slid stirring. Trans. Nnferrus Met. Sc. China 21 (2011) s274-s279 Technlgy, JMEPEG ASM Internatinal DOI: /s Gwri Shankar M.C, Jayashree P.K, RavirajShetty, AchuthaKiniand Sharma S.S. Individual and Cmbined Effect f Reinfrcements n Stir Cast Aluminium Metal Matrix IJESAT Mar-Apr