COMPOSITE MATERIALS WEC

What is a composite? A composite is a structural material which consists of combining two or more constituents Examples: – Concrete reinforced with steel – Epoxy reinforced with graphite fibers. – Flesh in your leg reinforced with bones WEC

Concrete Cement The most visible applications pave our roadways in the form of either steel and aggregate reinforced cement or asphalt concrete. WEC

Plywood Plywood is a common composite material that many people encounter in their everyday lives. WEC

An Introduction The objective is usually to make a component – strong and stiff, – often with a low density. WEC

Reinforcement Fiber particle flake Matrix Polymer Ceramics Metallic

Contd… An Introduction The majority of composite materials use two constituents: i-binder or matrix and ii- reinforcement.  The reinforcement is stronger and stiffer, forms backbone, while  The matrix keeps the reinforcement in a set place. The binder also protects the reinforcement, which may be brittle or breakable. WEC

Reinforcement forms Reinforcement can be in the form of: Continuous fiber – Organic fiber- i.e. Kevlar, polyethylene – Inorganic fiber- i.e. glass, alumina, carbon – Natural fiber- i.e. asbestos, jute, silk Short fiber whiskers Particle Wire WEC

Reinforcement Random fiber composites Continuous fiber composites Particulate composites Flake composites WEC

Different types of reinforcement for composites: (a) particle reinforcement; (b) short fiber reinforcement; (c) continuous fiber reinforcement; (d) laminate reinforcement Reinforcement for Composites WEC

Definition A combination of two or more materials (reinforcement, resin, filler, etc.), differing in form or composition on a macro-scale. The constituents retain their identities, i.e., – they do not dissolve or merge into each other, although they act in concert. Normally, the components can be physically identified and exhibit an interface between each other. WEC

Properties of Composites Composite materials consist of – two or more different (non-uniform solid) materials, that are – mechanically or metallurgically bonded together. Each component – retains its identity and – maintains its characteristic structure and properties. WEC

Properties of Composites Composite material generally possesses characteristic properties such as – stiffness, strength, hardness – high – temperature performance, – corrosion resistance, and conductivity, which are not possible with the individual components by themselves. WEC

Dependence of Properties The properties of composite materials depend on the following:  the properties of individual components  the relative amount of components  the size, shape, and distribution of discontinuous components  the orientation of various components  the degree of bonding between the components. WEC

What Makes Composites Useful? Advantages Lower density (20 to 40%) Higher directional mechanical properties (specific tensile strength (ratio of material strength to density) 4 times greater than that of steel and aluminium. Higher Fatigue endurance. Higher toughness than ceramics and glasses. Versatility and tailoring by design. Easy to machine. Can combine other properties (damping, corrosion). Cost

What Makes Composites Useful? Disadvantages Not often environmentally friendly. Low recyclability. Cost can fluctuate. Can be damaged. Anisotropic properties. Matrix degrades. Low reusability.

Classification of Composites The materials involved in making composites can be organics, metals, or ceramics. Accordingly there are many types of composites and several methods of classifying them. One method is based on geometry and consists of three distinct families: i.Structural (Laminar or layered composite ) ii.Particulate composites iii.Fiber – reinforced composites WEC

Classification of Composite Based on Geometry WEC

Classification based on Matrices Composite materials Matrices Polymer Matrix Composites (PMC) Metal Matrix Composites MMC) Ceramic Matrix Composites (CMC) ThermosetThermoplasticRubber WEC

Composites Fabrication Techniques Hand Layup Vacuum bagging Resin Infusion Resin Transfer Moulding Vacuum Assisted RTM Filament winding Tape Winding Sheet Moulding Compound Pultrusion Resin Injection Moulding Hydroclave Processing Autoclave Processing Compression Moulding Fibre Placement

Process Components

Vacuum Bagging

Areas of Application Aerospace Defense Automotive Sports Other applications WEC

Aerospace Applications Aerospace Applications frequently require – light weight, – high strength, stiffness, and fatigue resistance. WEC

BoeingBoeing 787 Dreamliner787 Dreamliner The new Boeing 787 Dreamliner structure including the wings and fuselage is composed of over 50 percent composites. Boeing 767 (and in 777, 787 airplanes w/ the latest, full wing box is composite) WEC

FIGURE - Schematic diagram showing the materials used in the various sections of the F-22 Raptor fighter airplane. Traditional materials, such as aluminum and steel, comprise only 20% by weight. Titanium accounts for 42%, and 24% is composite material. WEC

Marine Composites: state-of-the-art Swedish Navy Visby stealth corvette – 600 tons - 72 m long - FRP sandwich Royal Navy mine counter measures vessels – 725 tons - 60 m long - monolithic GRP WEC

Marine Composites: state-of-the-art VT Mirabella V sloop rigged yacht – 740 tones m long - 90 m mast – CFRP/GRP/polyolefin foam WEC

Fighter Jets WEC

Lear Fan 2100 “All-Composite” aircraft WEC

Space Shuttle The most advanced examples perform routinely on spacecraft in demanding environments e.g., aerospace components (tails, wings, fuselages, propellers etc). WEC

Sports Composites WEC

Recreational Equipment Recreational Equipment heavily dependent on technology, e.g., Snow Board – is a free riding, turn-tip board with cap & full wrap around edge Should be stiff & rigid, so one can rail them at high speed, launch & land the hugest airs fabricated from Advanced Composites, Its base is made of compressed Carbon, The other layers are made of fiber glass, ABS, polyurathane plastic & hardened steel. WEC

Recreational Equipment Mountain Bike - an integration of composite materials, like metals, elastomers, 8 Kg wt – still meets the tough requirement of sports. WEC

Sports composites In sports composites are used for: Golf club shafts, baseball bats, fishing rods, archery bows, tennis rackets, bicycle frames, Skis etc WEC

Automotive Uses WEC

Automotive uses In automotive uses of composite materials include: body panels drive shafts, springs, and bumpers. (Weight savings compared to existing parts is generally 20 to 25%). Truck manufacturers now use fiber-reinforced composites for cab shells and bodies, oil pans, fan shrouds, instrument panels, and engine covers. WEC

Railways Inter-City 125 locomotive cab WEC

Corvette Leaf Springs WEC

Other applications Other applications include such diverse products as boat hulls, bathroom shower and tub structures, chairs, architectural panels, agricultural tanks and containers, Wind blades pipes and vessels for the chemical industry, and external housings for a variety of consumer and industrial products. WEC

Pressure vessels WEC

Wind Blades WEC

Assets and Limitations The superiority of the various advanced composites over the conventional aerospace metals is clearly evident. WEC

Assets The weight of a graphite epoxy composite I-beam is less than – One-fifth that of steel, – One-third that of Titanium, and – One-half that of Aluminum. Its ultimate tensile strength – equals or exceeds that of the other three materials, and – it possesses an almost infinite fatigue life. WEC

Limitations The greatest limitations of composites are their relative brittleness and high cost of both materials and fabrication. While there has been considerable advancement in the field, manufacturing with composites can still be quite labor intensive, and there is a persistent lack of trained designers, established design guidelines and data, information about fabrication costs, and reliable methods of quality control and inspection. WEC

Defects Defects involve: delaminating, voids, missing layers, contamination, fiber breakage, and improperly cured resin (hard-to-detect). WEC

Assignment Glass Fibers, its types and properties. WEC

Thanks WEC