Mechanical Behavior, Testing, and Manufacturing Properties of MaterialsOverviewSlide 3Section 2.1 – 2.2.6TensionTensionSlide 7Slide 8DuctilityTrue-Stress and True-StrainConstruction of Stress-Strain CurvesSlide 12Strain at Necking in a Tension TestTemperature EffectsSection 2.2.7 – 2.7Rate of Deformation EffectsSlide 17Effects of Temp and StrainSlide 19SuperplasticityOther Deformation EffectsSlide 22CompressionCompression TestDisk TestTorsion TestSlide 27BendingBend / Flexure TestHardnessBrinell TestRockwell TestVickers TestKnoop TestMohs Hardness TestScleroscopeDurometerSection 2.7 – 2.12FatigueSlide 40Slide 41Slide 42CreepSlide 44Slide 45Slide 46ImpactSlide 48Slide 49Failure and Fracture of MaterialFailure and Fracture of MaterialFailure and Fracture of MaterialsFailure and Fracture in MaterialsFailure and Fracture in MaterialSlide 55Slide 56Slide 57Slide 58Slide 59Slide 60Slide 61Failure and Fatigue in MaterialSlide 63Slide 64Slide 65Slide 66Slide 67Slide 68Slide 69Residual StressesSlide 71Slide 72Work, Heat, and TemperatureSlide 74Slide 75Chapter 3Physical Properties of MaterialsPhysical Properties of Materials – Ch. 3DensitySlide 80Melting PointSpecific HeatThermal ConductivityThermal ExpansionElectrical, Magnetic and Optical PropertiesSlide 86Slide 87Slide 88Corrosion ResistanceSlide 90Slide 91Slide 92Slide 93Slide 94Slide 95Slide 96Slide 97Mechanical Behavior, Testing, and Manufacturing Properties of MaterialsGroup 4: Brenton Elisberg, Michael Snider, Michael Anderson, and Jacob HunnerOverview•Metals can be processed into various shapes by deforming them plastically under the application of external forces. The effects of these forces on material behavior are described in this chapter, including:Overview•Types of tests for determining the mechanical behavior of materials.•Elastic and plastic features of stress-strain curves and their significance.•Relationships between stress and strain and their significance, as influenced by temperature and deformation rate.•Characteristics of hardness, fatigue, creep, impact, and residual stresses, and their role in materials processing.•Effects of inclusions and defects in the brittle and ductile behavior of metals.•Why and how materials fail when subjected to external forces.Section 2.1 – 2.2.6•Tension Test–Strength –Ductility –Toughness–Elastic Modulus–Strain-hardening capability•Test Specimen–Usually solid and round–Original Gauge length lo–Cross-sectional area AoTension •Stress-strain curves–Linear elastic: elongation in the specimen that is proportional to the applied load.–Engineering stress: the ratio of the applied load P, to the original cross-sectional area, Ao, of the specimen. •Engineering stress equation: σ = P/Ao•Engineering strain equation: e = (l-lo)/loTension•Yield Stress: the stress at which permanent (plastic) deformation occurs.•Permanent (plastic) deformation: stress and strain are no longer proportional. •Ultimate tensile strength (UTS): the maximum engineering stress.Tension•If the specimen is loaded beyond its UTS it begins to “neck.”•Fracture stress: the engineering stress at fracture.Tension•Modulus of elasticity: ration of stress to strain in the elastic region.–Modulus of elasticity equation: E = σ/e•This linear relationship is known as Hooke’s Law.•Poisons Ratio: the ratio of the lateral strain to the longitudinal strain.Ductility •Ductility: extent of plastic deformation that the material undergoes before fracture.•Two measures of ductility:–Total elongation: (lf-lo)/lo x 100%–Reduction of Area: (Ao-Af)/Ao x 100%True-Stress and True-Strain•True-stress: ratio of the load, P, to the instantaneous cross-sectional area, A, of the specimen.•True-strain: the sum of all the instantaneous engineering strains.–True-stress equation: σ = P/A–True-strain equation: e = ln(l/lo)Construction of Stress-Strain Curves•The stress-strain curve can be represented by the equation: σ = Ken–K = strength coefficient –n = strain hardening exponent•Specific energy: energy-per-unit volume of the material deformed.Construction of Stress-Strain CurvesStrain at Necking in a Tension Test•True-strain at necking is equal numerically to the strain-hardening exponent, n, of the material.Temperature Effects•As temperature increases:–Ductility and toughness increase.–Yield stress and the modulus of elasticity decrease.•Temperature also affects the strain-hardening exponent of most metals, in that n decreases as temperature increases.Section 2.2.7 – 2.7•Rate of Deformation•Superplasticity•Effects of Compression, Torsion, and Bending •Hardness, Toughness, and StrengthRate of Deformation Effects•Some machines form materials at low speeds.–Hydraulic Presses•Some Machines form materials at high speeds.–Mechanical PressesRate of Deformation Effects•Deformation rate: the speed at which a tension test is being carried out, in units of m/s or ft/min.•Strain rate: a function of the specimen length.•Short specimens stretch more during the same time period than a long specimen would.Effects of Temp and Strain -Typical effects that temperature and strain rate have together on the strength of metals:–Sensitivity of strength-to-strain rate increases with temperature. –Increasing the strain rate increases the strength of the material (strain-rate hardening). –The slope of these curves is called the strain-rate sensitivity exponent. –The relationship between strength and strain is represented by:  = Cem–C is the strength coefficient and e is the true strain rate. m is the slope of the graph.Rate of Deformation Effects-Ex: You have 2 rubber bands, one 20 mm and the other 100mm in length. You elongate them both by 10mm in a period of 1 sec. The engineering strain in the shorter one is 10/20=.5 while the longer one is 10/100=.1, thus the strain rates are .5 s-1 and .1 s-1Superplasticity•Refers to the capability of some materials to undergo large, uniform elongation prior to necking and fracture. •This elongation can be as long as 200% to 2000% of the original length. •Common items that demonstrate this: bubble gum, glass (at high temp) and thermo plastics. –Because of this capability, some materials can be formed into complex shapes such as beverage bottles and even neon advertisement signs.Other Deformation Effects•Hydrostatic Pressure: pressure due to weight of a fluid.•Exposing some types of