REVIEW ON MANUFACTURING OF FUNCTIONALLY GRADED MATERIALS BY POWDER METALLURGY TECHNIQUE

Presented ByAmit JoshiM.Tech (Production Engineering )- II yearInvestigations on Sliding Wear Behaviour of Fibre Reinforced epoxy based Homogenous and their Functionally Graded Composites

1contentIntroductionWhat is a compositeFGM- a special class of compositeTypes of graded structureExamples of natural compositeAdvantages and challenges of FGMApplication of FGMManufacturing FGMConventional methods of manufacturing FGM

2importance of new materialsMore important than any one new application is the new materials concept itself Peter F. DruckerThe Age of Discontinuity, 1969

Human civilization has always tried to create things as per its own criterion and thus suiting and soothing their needs from centuries and thus technological development of human in all areas step by step can be seen by EVOLUTION.One area which is always in the human mind is the area of materials.

3What is a composite?A composite is a structural material which consists of combining two or more constituents which have quite different properties that when combined offer properties which are more desirable than the properties of the individual constituents.Examples: Wood with cellular fibers and reinforced with lignin.Flesh in leg reinforced with bonesConcrete reinforced with steelEpoxy reinforced with graphite fibers.

4Generally there are two phasesFiber as a reinforcementMatrix as a binderFibrous Composites

5Introduction to fgm- a special class of compositesFunctionally Graded Material concept was first proposed at Sendai, Japan in 1984.FGM on its simplest structure consists of one material on one side and a second material on the other side and an intermediate layer whose structure, composition and morphology vary smoothly from one material to the other at the micron level. FGM are multifunctional materials used for producing components that require functional performance which is variable within the component. This is basically termed as engineering the transition in micro/nano structures. Thus enhancing the overall performance of the component.

6What is FGM ?

7Types of Graded StructuresStepwise Graded StructuresAn example is a spark plug which gradient is formed by changing its composition from a refractory ceramic to a metal

Continuous Graded StructuresAn example is the human bone which gradient is formed by its change in porosity and compositionChange in porosity happens across the bone because of miniature blood vessels inside the bone

Note: Desired properties gradients may designed by controlling crystal structure and crystal orientation, particulate diameter, bonding state, etc.

8Example of a FGM IN NATUREThe human bone is a an example of a FGM. It is a mix of collagen (ductile protein polymer) and hydroxyapatite (brittle calcium phospate ceramic). The yellow marrow consists of fat which contributes to the weight and the red marrow is where the formation of red blood cells occur. A gradual increase in the pore distribution from the interior to the surface can pass on properties such as shock resistance, thermal insulation, catalytic efficiency, and the relaxation of the thermal stress. The distribution of the porosity affect the tensile strength and the Youngs modulus

9Advantages and Challenges of FGMsAdvantages of FGMsProvide multi-functionalityProvide ability to control deformation, dynamic response, wear, corrosion, etc. and ability to design for different complex environmentsProvide ability to remove stress concentrationsProvide opportunities to take the benefits (pros) of different material systems [e.g. ceramics and metals such as resistance to oxidation (rust), toughness, machinability, and bonding capability]Challenges of FGMsMass productionQuality controlCost1011APPLICATIONS OF FGMSENGINEERINGAEROSPACENUCLEAR ENERGYCHEMICAL PLANTELECTRONICSENERGY CONVERSIONSOPTICSBIOMATERIALSCOMMODITIESFUNCTIONALLY GRADED MATERIALSManufacturing FGMManufacturing process of a FGM can usually be divided into two steps:-(a)Gradation - Building an spatially inhomogeneous structure.(b)Consolidation - Transformation of these structure into bulk material. Note:- For FGM Development it is essential to have a wide database of properties of various materials for different chemical compositions say Youngs Modulus, coefficient of thermal expansion, Poisson's ratio, thermal conductivity etc. Once this knowledge is available the design of FGM is proposed keeping in mind the the need and application area.12Conventional methods for manufacturing fgmThe various techniques are classified as:-Melt casting process:- gravity casting, centrifugal casting, sedimentation casting, directional solidification. Powder metallurgy based techniques:- solid freeform, powder stacking, sheet lamination, wet powder spraying, slurry dipping. Electromagnetic/electrophoresis based techniques.Laser assisted techniques:- 3-D laser cladding, Laser engineered net shaping (LENS), Selective laser sintering.Others:- Chemical vapor deposition (CVD), physical vapor deposition (PVD), combustion synthesis, spark plasma sintering.

13Polymer Matrix CompositePolymer matrix composite is the material consisting of a polymer matrix combined with a fibrous reinforcing dispersed phase.

FRPA composite material consisting of a polymer matrix imbedded with high-strength fibers.Widely used in rubber products such as tires and conveyor belts.Principle fiber materials are: glass, carbon, and Kevlar 49 with glass (E-glass) the most common fiber material

14Polymer matrix compositeAttractive features of FRP:high strength-to-weight ratiohigh modulus-to-weight ratiolow specific gravitygood fatigue strengthgood corrosion resistance, although polymers are soluble in various chemicalslow thermal expansion, leading to good dimensional stability.15Materials and methodsEpoxy as matrix materialEpoxies have improved strength and stiffness properties over polyesters. Epoxies offer excellent corrosion resistance and resistance to solvents and alkalis. Cure cycles are usually longer than polyesters, however no by-products are produced.

Flexibility and improved performance is also achieved by the utilization of additives and fillers.

Due to several advantages over other thermoset polymers as mentioned above, epoxy resin is chosen as the matrix material for the present research work.

16Epoxy material propertyEpoxy resin is defined as a molecule containing more than one epoxide groups.The curing of epoxy is a chemical reaction in which the epoxide groups in epoxy resin reacts with a curing agent (hardener) to form a highly crosslinked, three dimensional network.

17Epoxy material propertyThe typical properties of epoxy are:Density- 1.16gm/ccYoungs modulus- 3.42 GPaPoissons ratio- 0.32Epoxy resins can be cure quickly and easily at practically any temperature from 5-150C depending on the choice of curing agent.

18Fiber materialsKelvar Fiber ReinforcementSuperior resistance to damage (Energy Absorber)Good in tension applications (Cables, Tendons)Moderate stiffnessMore expensive than glass

Carbon Fiber ReinforcementGood modulus high temperaturesExcellent stiffnessMore expensive than glassBrittleLow electric insulating properties

19Density ( g/cc)Tensile Strength ( GPa)Tensile Modulus( MPa)Elongation ( % )Poissons RatioYoung Modulus( GPa )Carbon Fiber1.791.804001.80.1070Aramid Fiber1.442.801302.50.2030Boron Fiber2.543.50400---E- Glass Fiber2.563.45704.80.2025S- Glass Fiber2.464.50865.30.25-Kevlar 49 Fiber1.443.81312.80.4276Mechanical properties of fibers20FGM and Homogeneous composite fabricationThe fibre material Kevlar & Carbon is mixed with epoxy resin in five different percentages (0wt.-%, 5wt.-% and 10wt.-%, 15wt.-% & 20wt.-%) by simple mechanical stirring technique and slowly poured in glass tubes so as to get cylindrical specimen.The graded composites with similar weight fraction of Kevlar fibre & Carbon fibre are cast by vertical centrifugal casting arrangement. The mixture of resin & fibre is filled in the cylinder mould. taken out of & centrifugation time is kept constant for 30min( 12 mm). The container is kept closed & is fitted on the centrifugal arrangement. The rotation speed is kept constant of 400rpm at room temperature , length 120 mm). Then after the mould is removed from the rotating system & kept for curing at room temperature for almost 24hours & then hardened composites samples are the in container.

21 Glass rodTest tubeParticlesExhaust airDisplay unitTime measuring unitR.P.M adjustment unitCoefficient of friction display unitWear rate display unit22Advantages (polymer matrix composite)High specific stiffness and strengthParts consolidationHigh durabilityFatigueCorrosionEfficient damping materials23wearThe progressive loss of material due to the dynamic interactions of two surfaces in relative motion contact is known as wear.The wear can be of many types: surface damageAbrasive wear Fretting wear Sliding and adhesive wearRolling contact wearImpact wearCorrosive wearOxidation wear.

24Sliding and adhesive wearGenerated by the sliding of one solid surface along another surface.Adhesive wear can be described as plastic deformation of very small fragments within the surface layer when two surfaces slides against each other.Adhesion is most clearly demonstrated in sliding systems when, for example, a shaft seizes in a bearing.25

26Research gap Less work done on fiber reinforced polymer based FGMThe general overview of literature does not indicate relevant work for finding the properties of hybrid composites i.e. combination of epoxy matrix with carbon fiber and Kevlar fiber. No work done on the combination of epoxy with Kevlar fiber & Caron fiber

27Objectives Fabrication and characterization of functionally graded fiber (carbon fibre and kevlar fibre) reinforced epoxy resin composites.Determining the Physical & Mechanical properties of FGM composites Conduct a tribological characterization of FGMs composites through wear volume and wear coefficient measurements obtained from pin on disk wear performance as a fraction of various operating variables.Statistical analysis of the experimental results and identification of significantly influential factors (control factors) using tagucchi technique in combination with analysis of variance (ANOVA) approach. 28

properties of glass fiber, carbon fiber and its compatibility with epoxy matrix is shown as underKevlar Fiber Kevlar Fiber is a common name of Polymer Matrix composite materials reinforced with Kevlar fibers. The most popular matrix materials for manufacturing Kevlar fibre are thermo sets such as unsaturated polyesters (UP) and epoxies (EP).Kevlar fiber are characterized by following properties High toughnessHigh modulus of elasticity to weight ratio.Good chemical and flame resistanceExcellent dimensional stability.Low thermal conductivity(compared to metals and ceramics).

Carbon Fiber Carbon fiber is a polymer matrix composite material reinforced by carbon fibers. The most popular matrix materials for manufacturing carbon fiber are thermo sets such as epoxy and polyesters.Carbon Fiber are characterized by following properties Very high modulus of elasticity exceeding that of steel.High tensile strength, which may reach 1000KsiLow density; 114lb/ft3High chemical inertness

29DesignationCompositionManualepoxy (100 wt% ) MK1epoxy + Kevlar fibre (0.25wt%) MK2epoxy + Kevlar fibre (0.5wt%)MK3epoxy + Kevlar fibre (0.75wt%)MK4epoxy + Kevlar fibre (1.0wt%)GK1epoxy + Kevlar fibre (0.25wt%) GK2epoxy + Kevlar fibre (0.5wt%)GK3epoxy + Kevlar fibre (0.75wt%)GK4epoxy + Kevlar fibre (1.0wt%)MC1epoxy + Carbon fibre (0.25wt%)MC2epoxy + Carbon fibre (0.5wt%)MC3epoxy + Carbon fibre (0.75wt%)MC4epoxy + Carbon fibre (1.0wt%)GC1epoxy + Carbon fibre (0.25wt%)GC2epoxy + Carbon fibre (0.5wt%)GC3epoxy + Carbon fibre (0.75wt%)GC4epoxy + Carbon fibre (1.0wt%)Designations and Detailed compositions of the FGMs & CompositesMechanical CharacterizationDensity and Void of fraction: Density of composite is calculated by the Agarwal & Broutman Expression th =

Where Wm= weight of matrix, Wf = weight of fiber, m= density of matrix, f = density of fiber, th= theoretical density of compositesVoid fraction:

th = Theoretical density of composites ce=Experimental density of composites

Future planSELECTED MATERIAL:

Epoxy resin selected is of grade LY250.Hardener of grade HY840 mixed in the ratio of 10:1 by weight.Kevlar fiber is Kevlar-49 fiberCarbon fiber selected is bidirectional met carbon fiber.

After selection of desired composition composites are than prepared and tested on dry sliding tester.

01/11/2010PRESENTATION, NIT HAMIRPUR32Questions please33Thank-you34