International Journal of Applied Engineering Research ISSN 0973-4562 Volume 12, Number 14 (2017) pp. 4460-4467 © Research India Publications. http://www.ripublication.com Evaluation of Properties of LM 25-Alumina–Boron Carbide MMC with Different Ratios of Compositions Dr.T.Vishnu Vardhan1 1Associate Professor, Dept. of Mech Engg, Madanapalle Institute of Technology & Science, Madanapalle, A.P, 517325, India Orcid Id: 0000-0003-4928-7180 U. Nagaraju2 2Assistant Professor, Dept. of Mech Engg, Madanapalle Institute of Technology & Science, Madanapalle, A.P, 517325, India. Orcid Id:0000-0003-2832-4173 Dr.G.Harinath Gowd3 3Professor, Dept. of Mech Engg, Madanapalle Institute of Technology & Science, Madanapalle, A.P, 517325, India Orcid Id:0000-0002-7531-8625 V.Ajay4 4Assistant Professor, Dept. of Mech Engg, Madanapalle Institute of Technology & Science, Madanapalle, A.P, 517325, India. Orcid Id:0000-0002-4272-5152 Abstract The fabricated samples are also micro examined for their internal structure and random orientation of particulates using In the present day scenario metal matrix composites (MMC’s) images, developed by scanning electron microscope. are showing their vital importance in the fields of aerospace and automotives. The major problem associated with the Key Words: LM-25; Boron carbide; Alumina; Stir casting; manufacturability of these MMC’s in non-uniform Mechanical properties, Microscopic Images, MMC. distribution of various particles due to their density difference. The random orientation of the particulates will show tremendous impact on their mechanical behavior; thus it is INTRODUCTION essential to determine the mechanical properties along with Now-a-days, Metal Matrix Composites (MMCs) are under the particulate distribution in MMC. serious consideration for a large number of structural The present work is focused on fabrication and investigation applications such as those in the aeronautical/aero-space, of Mechanical properties of aluminum alloy, alumina (Al2O3) transportation, defense and sports industries because of their and boron carbide MMC. These materials are identified in the superior properties. The excellent mechanical properties and process of investigation due to their high strength, better wear the comparatively less cost make them as an attractive option resistance and hardness of alumina and fracture toughness and [David L. et. al 1,2 (1985)]. A large number of fabrication excellent hardness property of boron carbide. techniques are currently used to manufacture the MMC materials according to the type of reinforcement used like stir Stir casting process is employed for the fabrication of MMC’s casting. It has been observed a rapid increasing utilization of and Mechanical properties of Aluminum alloy-Alumina- aluminum alloys, particularly in the automobile industries, Boron carbide metal matrix Composites are experimentally due to low weight, density, coefficient of thermal expansion, determined. The composition of MMC in varied for alumina high strength, and wear resistance[Vengatesh.D et. al.]. (1%, 4%,) and Boron carbide (4%, 1%) by keeping 95% by aluminum alloy. Dinesh Kumar et. al. [4] fabricated aluminum 6063 based 4460 International Journal of Applied Engineering Research ISSN 0973-4562 Volume 12, Number 14 (2017) pp. 4460-4467 © Research India Publications. http://www.ripublication.com metal matrix composites, one reinforced with silicon carbide, increasing Wt % of reinforcement particles up to 4% and graphite and second reinforced with silicon carbide, boron further there are decreasing. Jhony james et. al. [14] prepared carbide by stir casting technique. Various mechanical tests hybrid aluminum metal matrix composite reinforced with Sic like tensile test, flexural test, hardness test, and compared and TiB2. With varying weight % of reinforcement .K.R. results. And concluded that there is an increase in the value of Padmavathi et. al. (2014) have studied the wear and friction tensile strength, hardness value and flexural strength of a behavior of Al-6061 with various percentages volumes of composite Sic and B4c, particulates in comparison to the Sic, multiwall carbon nano tube and silicon carbide reinforcement graphite reinforced composite. N Subramani et. al. Fabricated through stir casting and then die casting. Siddique et. Al aluminum 2024 metal matrix composite reinforced with boron (2015) Siddique Ahmed Ghias and Vijaya Ramnath [2015] carbide, graphite by stir casting technique and their investigated the tensile property of Aluminum SiC Metal mechanical properties are evaluated. Matrix composite and found that hybrid composite has good strength. B.N.Saradaa et. al(2015)Particle distribution strongly S. Ramarao and G. Padmanabhan (2012) Fabricated influences the physical and mechanical properties of the aluminum alloy boron carbide composites using liquid composites. metallurgy techniques with particulates weight fraction of 2.5, 5 and 7.5 %. SEM images are developed and observed a uniform distribution of boron carbide particulates in EXPERIMENTAL DETAILS aluminum matrix. Madeva Nagaral et. al. (2013) have studied the mechanical behavior Al6061/Al2O/Graphite reinforced Materials MMC liquid metallurgy route. The hardness and tensile In this work for preparing metal–matrix composite, aluminum properties are evaluated and observed that addition of graphite alloy (LM 25) is used as base material; alumina and boron influence the tensile strength of composite. carbide in powder form are used as the reinforcements. Boron T. Raviteja et. al. (2014) have fabricated and evaluated the carbide having 220 mesh size, aluminum oxide and aluminum mechanical properties of Al-Sil2Cu/B4c composite by varying alloy ingot are required for the preparation. Aluminum alloy the weight of B4c particulates with 2, 4, 6, 8 and 10%. The ingot is cut into small pieces of 10mm x10mmx 30mm, so that result integrated that increasing the weight % of reinforcement it can be easily placed in graphite crucible for melting. particulates in the matrix have improved the hardness value by 6.97%, and tensile strength by 33%, when compare to base alloy. N.G. Siddesh kumar et. al. (2014) Have Aluminum alloy (LM 25) developedAl2219reinforced with B4C & MoS2 using stir The tensile properties of aluminum alloy (LM 25) at elevated casting technique and conducted experiment to evaluated temperatures are influenced by the condition (heat treatment) microstructure, density, micro hardness, tensile dry sliding of the castings and the duration at the elevated temperatures. wear test.P.B. Pawar et. al. (2014) Have developed a The heat-treated alloy has good machining properties. They composite by adding silicon carbide in aluminum metal by are of high resistance to corrosive attack by sea-water and mass ratio 2.5%, 5%, 7.5% and 10%. Mechanical tests such as marine atmospheres hardness test, microstructure test are conducted and that the hardness and material toughness where enhance with the addition of silicon. Aluminum oxide or alumina B. Vijaya Ramnath et. al (2014) have fabricated had Aluminum oxide (Al2O3) is a chemical compound of investigated are mechanical properties and inner structure of aluminum and oxygen. It is commonly called alumina. Al2O3 aluminum ally, alumina (Al2O3), and boron carbide metal is an electrical insulator but has a relatively high thermal matrix composite. Gurwinder singh et. al. (2014) developed a conductivity (30 W m -1 K -1) like ceramic material. Its hybrid composite of aluminum with Sic, Al2O3 and C particles hardness makes it suitable for use as an abrasive and as a cut- using squeeze casting technique. Hardness test, impact test are ting tool. performed on samples and concluded that the squeeze performed from Al reinforced with Sic/Al2O3/C is clearly superior to base Al comparison of impact strength and Boron carbide hardness. Boron carbide is one of the mainly hopeful ceramic materials Bhargavi rebba et. al. (2014) did experimental investigates are due to its attractive properties, including high strength, low molybdenum disulphide powders reinforced in Al 2024. The density, exceptionally high hardness (the third hardest comparison ratios 1, 2, 3, 4, 5-weight % of MoS2 powders of material after diamond and boron nitride), good chemical approximately 40µm using stir casting technique hardness and stability and neutron combination capability .Boron carbide tensile strength of the specimen are evaluated and observed has stability to ionizing radiation. Its hardiness is almost equal that the hardness and tensile strength increased with the to diamond. The properties of aluminum alloy (LM 25), 4461 International Journal of Applied Engineering Research ISSN 0973-4562 Volume 12, Number 14 (2017) pp. 4460-4467 © Research India Publications. http://www.ripublication.com alumina and boron carbide are shown in Table 1. automatic stirring of the material takes place for 10 min with 550 rpm of stirring rate, there-by uniformly dispersing the additive powders in the aluminum alloy matrix. The Table 1: Properties of Materials used temperature rate of the furnace should be controlled at 8300 ± 100 C in final mixing process. The degasser removes all the Material Tensile Density Coefficient Modulus of trapped gases from the mixture in the crucible and ensures strength (g/cm3) of thermal Elasticity that the temperature of the mixture in the crucible does not get (Mpa) expansion (Gpa) transferred easily to the atmosphere. This experiment is (10-6/oC) repeatedly done by varying the compositions of the composite powder.