Experimental Investigation of Mechanical Properties of Al7075 Hybrid Reinforced with Mica Particulates and E-Glass Fibres

In this present investigation efforts are made to study the mechanical properties of as cast Mica particulates and Short E-glass fibers reinforced AA7075 Hybrid composites containing mica particulate of 200 microns and short E-Glass fibers of 2-3 mm length in different compositions. The vortex method of stir casting was employed, in which the reinforcements were introduced into the vortex created by the molten metal by means of mechanical stirrer. Castings were machined to the ASTM standards on a highly sophisticated lathe. The degree of improvement of mechanical properties of MMCs is strongly dependent on the kind of reinforcement. An improved mechanical properties occurs on reinforced compared to Unreinforced MMCs alloys.


INTRODUCTION
Metal is a chemical element that is a good conductor of both electricity and heat forms cat-ions and ionic bonds with non-metals. In chemistry, a metal is an element, compound, or alloy characterized by high electrical conductivity. An alloy is a mixture of two or more element in solid solution in which the major component is a metal. Most of pure metals are either too soft, brittle or chemically reactive for practical use. Combining different ratios of metal as alloys modifies the pure metals to produce desirable characteristics.
Metals are used because of desirable properties such as low weight, higher conductivity, and resistance to corrosion. Example: Aluminium, Copper, Brass, Silver, Lead. To evaluate the composite materials as well as the base matrix Alloy Al 7075 to determine the tensile strength behavior studies on different composition.

EXPERIMENTAL DETAILS
Following steps are carried out in our experimental work: 1. Casting 2. Machining 3. Testing

Casting
Casting is a manufacturing process by which a liquid metal is poured into mould which contains hallow cavity of desired shape and then allowed to solidify, the solidified

Machining
After the casting, machined according to ASTM standards on highly sophisticated lathe. As per the ASTM standard E8 tensile test was conducted using a computerized universal testing machine. The tensile test uses specimens of 20 mm grip diameter, 30 mm grip length, 62.5 mm gauge length, 75 mm length of reduced cross section, inner diameter of 12.5 mm and total length 155 mm and it is shown in the figure 2.5. For the hardness test uses the specimen of 20mm diameter, 30mm length and it is shown in the figure 2.6. For the microstructure test uses the specimen of 20 mm diameter, 20 mm length.

Tensile test
The tensile test was conducted using a computerized universal testing machine as per the ASTM E8 standard.
The test uses specimens of 20 mm grip diameter, 30 mm   From this graph we observe that the UTS increase as the percentage of Mica is increased, but it is also observed that with the increase in the addition of E-glass also increases UTS.   From this graph we observe that the Hardness increase as the percentage of Mica is increased, but it is also observed that with the increase in the addition of E-glass also increases Hardness.   From this graph we observe that the % of elongation decreases as the percentage of Mica is increased, but it is also observed that with the increase in the addition of E-glass also decreases % of elongation.    The degree of improvement of mechanical properties of MMCs is strongly dependent on the kind of reinforcement as well as its volume fractions.
 As the addition of mica and E-glass reinforcement increases the UTS of aluminium 7075 alloy.

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As the addition of mica and E-glass reinforcement in aluminium 7075 alloy, there increase hardness, due to the presence of silica content in both reinforcement.

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There is a predominant decrease of ductility (% of elongation) of aluminium 7075 alloy, due to the addition of mica and E-glass reinforcement.