Presentation for

Minor Project

Development ofAluminum alloy – Silicon Carbide composite

(AMC) &

it’s wear resistance characterization.

Prepared by :-Yogesh Baghel

Contents1.Introduction2.Importance3.Essence of aluminum alloy4.Literature survey

a) What is MMC ?b) How it is manufactured ?c) Advantages of MMC.

5.Plan of our work.6.Expected outcomes.7.Experimental procedure.8.Essence of aluminum alloy9.Consideration of wear resistance.10.Microstructure analysis.11.Conclusion.12.Reference.

IntroductionA new class of structural materials has emerged as new

generation engineering materials, which are gaining popularity in recent times due to some advantages they have over other materials.Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or microscopic scale within the finished structure. Composite materials are usually used for producing high-performance products.

ImportanceAt present it is very essential to choose a perfect

material for a particular application. It is very tough to get all characteristics in one material so there is a need of combine the properties of two or more material. For this the idea of composite is generated. And various experiment regarding these has been done.

Aluminum is selected as a composite material because of the following advantages –•Good thermal conductivity.•Good corrosion resistant.•Low density.•High strength to weight ratio.

Essence of aluminum alloy

What is MMC ?A composite material in which one constituent is

metal or alloy forming at least one percolating network. The other constituent is embedded in this metal matrix and usually serves as reinforcement.This project involves production of MMC made of aluminium alloy reinforced with Silicon Carbide to develop wear resistance properties.

How it is manufactured ?MMC manufacturing can be broken into three

types: solid, liquid and vapor.Solid state methods1.Powder blending and consolidation (powder metallurgy): Powdered metal and discontinuous reinforcement are mixed and then bonded through a process of compaction, degassing, and thermo-mechanical treatment.2.Foil diffusion bonding: Layers of metal foil are sandwiched with long fibers, and then pressed through to form a matrix.

Liquid state methods1.Electroplating / Electroforming: A solution containing metal ions loaded with reinforcing particles is co-deposited forming a composite material.2.Stir casting: Discontinuous reinforcement is stirred into molten metal, which is allowed to solidify.3.Squeeze casting: Molten metal is injected into a form with fibers preplaced inside it.4.Spray deposition: Molten metal is sprayed onto a continuous fiber substrate.5.Reactive processing: A chemical reaction occurs, with one of the reactants forming the matrix and other the reinforcement.

Vapor deposition1. Physical vapor deposition: The fiber is passed through a thick cloud of vaporized metal, coating it.

Controlled unidirectional solidification of a eutectic alloy can result in a two-phase microstructure with one of the phases, present in lamellar or fiber form, distributed in the matrix.

Advantage of MMC

• Light Weight

• Performance at higher temperatures

• High Strength

• Low Density, Better wear resistance.

Plan of workPhase 1Size gradation-

The reinforced material’s size gradation has been selected through sieve shaking.

Phase 2Production of MMC-

This will be done by using foundry method. Aluminium Alloy is matrix material whereas SiC is reinforcement material. MMC will be produced using 3 phase Electric Resistance Furnace for melting and stirrer is used for stirring the melt. This is also called as the Stir Cast Method. Production of casting-

Liquid metal will be poured into preheated cast iron moulds and allowed to solidify.

Al-SiC composite made by us

 Phase 3Characterization –

  Abrasive Wear Testing, Investigation of microstructure of the composite using Optical Microscopy and SEM and Hardness Tests.

A rough sketch of the 3-body Abrasive Wear Testing Equipment.

Expected outcome•Microscopic Examinations of composites by SEM (Scanning Electron Microscope) will show the distribution of reinforcement particles in Aluminium Alloy matrix.•The wear resistance of composites is much greater than the commercially pure aluminium. •Different wear mechanisms has to be operated under the test conditions of variation of normal loads, composition, and sliding velocity .• Analysis and comparison of different test will be conducted and then according to the results obtained conclusion will be drawn.

•Fabrication of Abrasive Wear Testing machine will help in finding out the wear characteristics of composite.•SiC is a good abrasive material so reinforcement of SiC will lead to better wear properties.•It is therefore expected that the incorporation of SiC particles in Aluminium Alloy will help to develop a wear resistance type of material.•The composites produced are likely to overcome the cost barrier for wide spread applications in automotive and small engine applications.

Experimental procedureIn the present investigation the MMC has been

developed in the lab stir caster (supplied by VB ceramic chennai). Non oxide Ceramic particles like SiC of mesh size 200 has been incorporated as a reinforced particle as its melting point is of higher range. Due to unavailability of Pure Al, we have chosen commercial aluminum alloy where silicon content is in micro lavel. In the first phase of the work, the reinforced material’s size gradation has been selected through sieve shaking . Through size gradation we have got different grade from 85 to 500 mesh. We have chosen 200 mesh for our experiment as it is very fine as well as to be homogenized.

In second phase of the work, the said reinforced material has been taken to stir caster and pour into the semi viscous alumina matrix at almost 680 c. and stirring was immediately done for 5-10 min having a rpm range of 400 to 500. after proper settling of the injected composite was collected and immediately normalize for almost 30 min.

the so called metal was taken to the diamond cutter machine and the cutting part was taken for polishing and etching in order to make it favorable to micro structural analysis.

The microstructure analysis was initially performed in image analyzer and the result has been shown in microstructure analysis slide.

the pending works like hardness testing, wear resistance testing and SEM analysis will be performed in the third phase of this investigation.

Consideration of wear resistance

•Wear is a phenomenon observed at the surfaces, whenever there is a relative motion between two surfaces. It is a progressive loss of material subjected to load and relative motion. •Erosive wear is the severest type of wear.•Aluminum Composites are mainly used in machinery, aircraft and automobile industry.•Hence, it becomes necessary to check the effectiveness of the composite we produce by wear resistance test before putting it into application.

Microstructure analysis-1

Pure aluminum Al-SiC composite

Magnification = X10 Magnification = X10

Fig 1 Fig 2

Microstructure analysis-2

Magnification = X5

Al-SiC composite

Fig 3

Microstucture analysis-3 Al-SiC composite

Magnification = X100Fig 4

ConclusionIn the present investigation an attempt has been given

to establish the initial works (phase 1, phase 2 & part of phase 3). From the microstructure study through image analyzer , it is clear that our selected reinforced material (SiC) has been able-bodied throughout the aluminum matrix as shown in fig 3 .fig 1 has been checked at a magnification range of X10.

fig 4 has been taken at X100 and this shows a clear vision of our SiC in an exposed mode.

UnderstandingWhile grinding the MMC, we have faced a problem as

the material becomes hard rather than soft aluminum itself. This phenomenon encourages us to go into the wear investigation and simultaneously same test will give us the detail topography of the surface at higher magnification. So we will go accordingly in near future.

Reference1. www.en.wikipedia.org/wiki/Metal_matrix_composite 2. Basics of Metal Matrix Composites - Wiley-VCHwww.wiley-vch.de/books/sample/3527313605_c01.pdf

Thank You