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Manufacturing with CompositeCompetenciesCompositesSlide 4Classification of composite materialSlide 6The Reinforcing PhaseSlide 8Slide 9Slide 10Slide 11Slide 12Slide 13METAL MATRIX COMPOSITESSlide 15Slide 16Slide 17CERAMIC MATRIX COMPOSITESSlide 19POLYMER MATRIX COMPOSITESSlide 21Slide 22Slide 23IT 208 Chapter 19 1Manufacturing with CompositeChapter 19IT 208Chapter 192CompetenciesDescribe the use of different types of fabrics and the importance of the fabric directionDescribe the different types of matrix phases upon which composites are based.Describe the function of the primary and secondary phase in a composite material.Describe the difference between simple and advanced compositesIdentify the manufacturing techniques of compositesList the advantages and disadvantages of plastics and compositesIT 208Chapter 193CompositesA judicious combination of two or more materials that produces a synergistic effect. A material system composed of two or more physically distinct phases whose combination produces aggregate properties that are different from those of its constituents.IT 208Chapter 194CompositesA composite material consists of two phases:Primary•Forms the matrix within which the secondary phase is imbedded•Any of three basic material types: polymers, metals, or ceramicsSecondary•Referred to as the imbedded phase or called the reinforcing agent•Serves to strengthen the composite. (fibers, particles, etc.)•Can be one of the three basic materials or an element such as carbon or boronIT 208Chapter 195Classification of composite materialMetal Matrix Composites (MMCs)•Include mixtures of ceramics and metals, such as cemented carbides and other cermets, as well as aluminum or magnesium reinforced by strong, high stiffness fibersCeramic Matrix Composites (CMCs)•Least common composite matrix. Aluminum oxid and silicon carbide are materials that can be imbedded with fibers for improved properties, especially in high temperature applicationsPolymer Matrix Composites (PMCs)•Thermosetting resins are the most widely used polymers in PMCs. Epoxy and polyester are commonly mixed with fiber reinforcementIT 208Chapter 196Classification of composite materialMatrix material serves several functions in the composite •provides the bulk form of the part or product•holds the imbedded phase in place•shares the load with the secondary phaseIT 208Chapter 197The Reinforcing PhaseThe imbedded phase is most commonly one of the following shapes:•Fibers•Particles•FlakesIT 208Chapter 198The Reinforcing PhaseFibersDiameters range from .0001 in to about .005 in depending on the material. Generally circular in cross-section, but can also be in the form of tubular, rectangle, hexagonal.Fibers used can be either continuous or discontinuous•Continuous fibers – are very long; in theory, they offer a continuous path by which a load Can be carried by the composite material•Discontinuous fibers – are short lengthsIT 208Chapter 199The Reinforcing PhaseOrientation of fibers is an important consideration. One-dimensional•maximum strength and stiffness are obtained in the direction of the fiberPlanar •in the form of two-dimensional woven fabricRandom or three-dimensional •the composite material tends to posses isotropic propertiesIT 208Chapter 1910The Reinforcing PhaseTypes of fabrics Currently, the most common fibers used in composites are glass, graphite (carbon), boron and Kevlar 49. Glass – most widely used fiber in polymer composites, the term fiberglass is applied to denote glass fiber-reinforced plastic (GFRP)•E-glass – strong and low cost, but modulus is less than other (500,000 psi)•S-glass – stiffer and its tensile strength in one of the highest of all fiber materials (650,000 psi). Has about five times the tensile strength of steel and has a density of about one third that of steelIT 208Chapter 1911The Reinforcing PhaseCarbon – are generally a combination of graphite. Graphite has a tensile strength three to five times stronger than steel and has a density that is one-fourth that of steel. Boron – very high elastic modulus, but its high cost limits its application to aerospace componentsCeramics – Silicon carbide (SiC) and aluminum oxide (Al2O3) are the main fiber materials among ceramics. Both have high elastic moduli and can be used to strengthen low-density, low- modulus metals such as aluminum and magnesiumMetal – Steel filaments, used as reinforcing fiber in plasticsIT 208Chapter 1912The Reinforcing PhaseParticles and FlakesParticlesIs an important material form for metals and ceramics range in size from microscopic (less than 1 micron) to macroscopic (greater than 1 micron)•In the microscopic size range and proportion of imbedded material of 15% or less, the particles result in strengthening the matrix•In the macroscopic size range and proportion of imbedded material of 25% or more, the particles serve to share the load with the matrix material. •This form of composite strengthening occurs in cemented carbides, in which tungsten carbide (80%) is held in a cobalt binder.IT 208Chapter 1913The Reinforcing PhaseFlakesBasically, two-dimensional particles ranging 0.01 to 1.0 mm in across the flake, with a thickness of 0.001 to 0.005 mmIT 208Chapter 1914METAL MATRIX COMPOSITESCommon reinforcing phase includes•Particles of ceramic (commonly called cermets)•Fibers of various materials, including other metals, ceramics, carbon, and boronFRMMC – combine the high tensile strength and modulus of elasticity of a fiber with metals of low density, thus achieving good strength-to-weight and modulus-to-weight ratios in the resulting composite material.IT 208Chapter 1915METAL MATRIX COMPOSITESCemented carbides are composed of one or moreCarbide compounds bonded in a metallic matrixCommon cemented carbides are based on:Tungsten carbide (WC)Titanium carbide (TiC)Chromium carbide (Cr3C2)Tantalum carbide (TaC)IT 208Chapter 1916METAL MATRIX COMPOSITESCarbide ceramics constitute the principal ingredient in cemented carbides, typically ranging in content from 80% to 95% of total weight.Principle metallic binders are:•Cobalt – used for WC•Nickel - used TiC and Cr3C2IT 208Chapter 1917METAL MATRIX COMPOSITESCutting tools are the most common application of cemented carbides based on tungsten carbideTitanium carbide cermets are used principally for high


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