CHARACTERISATION OF ALUMINIUM 7075/SiCp COMPOSITES GUIDED BY Mr. S.S.Nivas M.E., Asst prof/ Mechanical A.V.C COLLEGE OF ENGINEERING Mr. S. Rajamuthamilselvan M.E., Asst prof / Mechanical Annamalai University PRESENTED BY M.Dinesh (80107144012) S.Manikandan (80107144023) P.Manikandan (80107144024)

Introduction A composite material is a combination of two or more chemically distinct materials to form a stronger material. The term “composite” broadly refers to a material system which is composed of a discrete constituent (the reinforcement) distributed in a continuous phase (the matrix), and which derives its distinguishing characteristics from the properties of its constituents, from the geometry and architecture of the constituents, and from the properties of the boundaries (interfaces) between different constituents. Composite materials are usually classified on the basis of the physical or chemical nature of the matrix phase, e.g., polymer matrix, metal-matrix and ceramic composites.

Need for the study 1. To fabricate 7075Al/SiCp composites through stir casting technique 2. To study tensile strength of 7075Al/SiCp composites 3. To study impact strength of 7075Al/SiCp composites 4. To study hardness of 7075Al/SiCp composites 5. To study micro structure of composite materials  

Aluminium matrix composites High performance aluminium centric material systems. The reinforcement inAMCs could be in the form of continuous/discontinuous fibres, whisker or particulates, in Aluminium matrix composites (AMCs) refer to the class of light weight volume fractions ranging from a few percent to 70%. Aluminum matrix composites (AMCs) have been widely studied since the 1920s. They offer a large variety of mechanical properties depending on the chemical composition of the Al-matrix. They are usually reinforced by Al2O3, SiC, C but SiO2, B, BN, B4C, AlN may also be considered

MIXING OF COMPOSITES STIR CASTING PROCESS One of the prominent and economical route for development and processing of metal matrix composites materials. Properties of these materials depend upon many processing parameters and selection of matrix and reinforcements. Literature reveals that most of the researchers are using 2, 6 and 7075 aluminum matrix reinforced with SiC particles for high strength properties whereas, insufficient information is available on reinforcement of "Al2O3" particles in 7075 aluminum matrix.

Melting of alloys : Stir casting process

Casting process : Mould sample :

Preparation of samples Prepared standard in lathe :. specimens for Preparation of samples Prepared standard in lathe : specimens for tensile test :

Various test conducted Tensile test Impact test Hardness test Microscopic test

IMPACT TEST SNO SIZE OF THE SPECIMEN LOAD IN JOULES 1 2 3 4 5 6 7 8 15 20 18 16 28 26 24 32

HARDNESS TEST: SNO MIN LOAD kgf MAX LOAD SCALE R.H.NO 1 2 3 4 5 6 7 8 MATERIAL MIN LOAD kgf MAX LOAD SCALE R.H.NO 1 2 3 4 5 6 7 8 15 20 60 100 B 90 75 92 71 73 65 66 61 91 95 89 74 85 82 77 94 86 79 72 Avg 91.3 85 92.6 83.3 77.6 76.6 73.3 70.6

Tensile test: s.no Material Peak load in KN Displacement at FMAX In mm Breaking load in KN Max displacement in mm Area in sq.mm Ultimate stress in KN/sq.mm UTS in mpa 1 5m-10% 12.434 7.160 3.830 7.350 50.286 0.247 247 2 5m-15% 12.294 9.440 2.201 9.710 0.244 244 3 5m-20% 16.947 11.608 2.637 15.590 0.337 337

Microstructure of the composites ADDITION OF sic-10% ADDITION OF sic-15% ADDITION OF sic- 20%

Industrial Application (1) Brake rotors for German high speed train and made from a particulate reinforced aluminum alloy. Compared to conventional parts made out of cast iron with 120 kg/piece, the 76 kg of the AMC rotor offers an attractive weight saving potential. (2) The braking systems (discs, drums, calipers or back-plate) of the New Lupo from Volkswagen made from particulate reinforced aluminum alloy supplied by Duralcan.

(3) AMC continuous fiber reinforced pushrods produced by 3M racing engines. These pushrods weigh 40% as much as steel, are stronger and stiffer, and have high vibration damping. (4) AMC wires also developed by 3M for the core of a electrical conductors. The unique properties of this type of conductor offer substantial performance benefits when compared to the currently used steel wire reinforced conductors.

Advantages Improved stiffness Reduced density(weight) Greater strength Improved stiffness Reduced density(weight) Controlled thermal expansion coefficient Thermal/heat management Improved abrasion and wear resistance Control of mass (especially in reciprocating applications) Improved damping capabilities.

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