Table 1. Property Spectrum of Engineering MaterialsMATERIALMATERIAL PROPERTIES

METALSCHEMICALPHYSICAL MECHANICALDIMENSIONAL

Composition Microstructure Phases Grain size Corrosion resistance Inclusion

Melting point Thermal Magnetic Electrical Optical Acoustic Gravimetric Color Tensile/compressive properties Toughness Ductility Fatigue Hardness Creep resistance Shear strengthAvailable: Shapes Sizes Surface texture Manufacturing tolerances

PLASTICS Composition Fillers Crystallinity Molecular weight Flammability Spatial configuration Chemical resistance Tensile/compressive properties Heat distortion pV limit toughness

Manufacturing tolerances Stability Available sizes

CERAMICS Composition Porosity Grain size Crystalline structure Corrosion resistance Tensile/compressive properties Fracture toughness Hardness Available: Shapes Sizes Surface texture Manufacturing tolerances

COMPOSITES

Composition Matrix/reinforcement bond Volume fraction of reinforcement Reinforcement nature Corrosion resistance

Hardness Creep resistanceAvailable: Shapes Sizes Manufacturing tolerances Stability

The spectrum of material properties and how they apply to various material systems (physical properties apply equally to all systems).1. Chemical properties are material characteristics that relate to the structure of a material and its formation from the elements.2. Physical properties pertain to the interaction of these materials with various forms of energy and with other forms of matter3. Mechanical properties are material characteristics that are displayed when a force is applied to the material relative to the elastic or inelastic behavior of the material Indicate the suitability of a material for use in mechanical application: carry load, absorb shock, resist wear, etc.4. Dimensional properties refer to the shapes, sizes, manufacturing tolerances and finishPHYSICAL PROPERTIES melting point point at which the material liquefies in heating or solidifies on cooling density, mass of a material per unit volume = m/V specific gravity, (sp.gr.) ratio of the mass or weight of solid or liquid to the mass or weight of an equal volume of water = mx/mw thermal conductivity, k rate of heat flow/unit time in a homogeneous material/unit area (std.cond)/unit temperature gradient in a direction perpendicular to the area.

Q = kA[t/x]

Q x thot width tcold lengthWhere: Q = quantity of heat flowing thru a material, BTU(watt) t = th tc = temperature differential A = area thru which the heat will flow = width*length x = thickness k = thermal conductivity, BTU-ft/hr/ft2/oF [watt/m-oK

thermal expansion, (linear coefficient) the rate at which the material elongates when heated the rate is expressed as unit increase in length/unit increase in temperature = /t*L Specific heat, c The ratio of the amount of heat required to raise the temperature of a unit mass of a substance 1o(oC or oF) to the heat required to raise the same mass of water 1o Q = mct Poissons ratio, Absolute value of the ratio of the transverse strain to the corresponding axial strain in a body subjected to uniaxial stress = d/L = c/t c = d/di t = L/Li where: c = compressive strain t = tensile strain

MECHANICAL PROPERTIES Tensile strength ratio of the maximum load in tension to the original cross-section of test material SU = FMAX/Ai

Yield strength the stress at which a material exhibits a specified deviation from proportionality of stress and strain

Compressive strength maximum compressive stress that a material is capable of withstanding

Flexural strength the outer fiber stress developed when a material is loaded as a simply supported beam and deflected to a certain value of strain

Shear strength the stress required to fracture a material in a cross-sectional plane that is parallel to the force applied. Ss 40% St

Percent elongation the increase in the gage length measured after the specimen fractures within the gage length % e = Lf - Li Li Ductility is the degree to which a material will deform before the ultimate fracture and the opposite of brittleness. Ductile > 5% Brittle 5% Percent reduction the difference between the original area to the final area measured after the fracture of the test specimen. %R =( Ai Af)/Ai

Modulus of Elasticity a measure of rigidity/stiffness of a material; ratio of stress to strain in a material

E = S/

Hardness, H resistance of a material to plastic deformation usually indentation; measured according to the hardness teat undergone: Knoop, Brinell, Rockwell, ShoreH code: ASTM, ANSI(American Standards Institute) and ISO

Endurance Limit the maximum stress which a material can theoretically endure an infinite number of stress cycle Creep time dependent permanent strain under stress Creep strength the constant nominal stress that will cause a specified quantity of creep in a given time at constant temperature expressed in units of % in a period of time(hours) Stress rupture strength the nominal stress at fracture in a tension test at constant load and constant temperature (usually elevated); complements creep and shows the stress at which a part will fail under sustained load and at elevated temperature

Impact strength amount of energy required to fracture a given volume of material

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