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Technical Seminar onOverview of Functionally Graded Materials ByMr. Pradeepkumar chikkamath2VX13MPD11M.Tech 2nd semVTU Belgaum

Under the guidance of:Prof. Dr.R.R.Malagi Asst.Prof.Anil Pol Asst.Prof.Prasad Raikar

Agenda

IntroductionLiterature surveyClassificationWhy Functionally Graded MaterialsApplicationsAdvantages Future scopeConclusion

Introduction

The class of materials which both its composition and structure gradually change over volume therefore changing the properties of the material in order to perform a certain function(s). Thus, material properties depend on the spatial position in the structure. The properties that may be designed/controlled for desired functionality include chemical, mechanical, thermal, and electrical propertiesLiterature Survey

1.Fundamentals of Functionally Graded Materials: Processing and Thermomechanical Behaviour of Graded Metals and Metal-Ceramic Composites, S. Suresh and A. Mortensen Material Science and Engineering A362 (2013) 481-5; 2.Processing Techniques for Functionally Graded Materials, B.Kieback, A. Neubrand, H.Riedel, Material Science and Engineering A362 (2003) 81-105; 3. Infiltration and physical characteristics of functionally graded alumina/calcium-hexaluminate composites, D.Asmi, I.M. Low, Journal of Material Processing Technology, 118 (2001) 225-230 4.Fundamentals of liquid phase sintering for modern cermets and functionally graded cemented carbonitrides (FGCC), Limin Chen, Walter Lengauer, Peter Ettmayer, Klaus Dreyer, Hans W. Daub, Dieter Kassel, International Journal of Refractory Metals and Hard Materials 18 (2000) 307-322; 5.Synthesis of functionally gradient NiCr-Al/MgO-ZrO2 coating by plasma spray technique, S. Eroglu, N.C.Birla, M.Demirci, T. Baykara, Journal of Material Science Letters 12 (1993), 1099-1102;

Classification

FGMs may be compositionally or micro-structurally graded

The gradient is established through a transition function (usually volume fraction as a function of one or more spatial coordinates)

FGMs come in several types, depending on their constituents (e.g. ceramic-metal, metal-metal)

ContinuousSteppedGradationCeramic-Metal TiC-Ni, Mullite-Mo, Al-AlB2

Metal-Metal/Intermetallic W-Cu, W-Mo, Al-Al3Fe

Metal-Polymer Al-Polycarbonate

OthersSingle material (variation in porosity)Glass CeramicCeramic - Ceramic

Pure Component BPure Component A% Component A% Component BModeling of FGMs

E1E2

E1E2

2) Halpin-Tsai More complex, takes into account the aspect ratio of the inclusions (s)1) Linear rule of mixtures (function of local volume fraction)In general, applicable only to metal-metal FGMs, may be used as a first approximation for different compositionsModeling of Functionally graded materials

Natural Example for FGMs The 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 Ceramic-metal FGMs are particularly suited for thermal barriers in space vehicles.Other possible uses include combustion chamber insulation in ramjet or scramjet enginesThey have the added advantage that the metal side can be bolted onto the airframe rather than bonded as are the ceramic tiles used in the Orbiter.Aerospace Applications

We come across Functionally graded materials in our daily life

Structural walls that combine two or more functions including thermal and sound insulationEnhanced sports equipment such as golf clubs, tennis rackets, and skis with added graded combinations of flexibility, elasticity, or rigidity

Enhanced body coatings for cars including graded coatings with particles such as dioxide/micaFuture ScopeThe study was just an overview about the Functionally graded materials and study can be specialized in regards to required propertiesThe study can also be carried on the micro structure of the materials and Nanostructure which can yield much better results The research regarding the machinabelity and weldebelity are in process.Analytical Modeling using higher order functions for this class of materials can help the engineer to select the best suited materials for use hence higher order o functions need to be formulated

ConclusionThe Functionally graded materials study is the new area of study the beauty of this class of materials is that any desired property at any corner of space of the product can be achieved in order to sustain any kind of loading conditions.Functionally graded materials serves their capability best in the field of aerospace, nuclear power , automotive power transmission and Biomedical fields.

Queries?