All terms related to physical properties of materials.
Abrasion Resistance
Degree of resistance of a material to abrasion or wear.
Abrasive Wear
The displacement and / or detachment of metallic particles from a surface as a consequence of being exposed to flowing fluids or gases.
Brinell Hardness
The value of hardness of a metal on an arbitrary scale representing kg/mm2, determined by measuring the diameter of the impression made by a ball of given diameter applied under a known load. Values are expressed in Brinell Hardness Numbers, BHN.
Corrosion Index
A number expressing the maximum depth in microns or mils to which corrosion would penetrate in one year on the basis of a linear extrapolation of the penetration occurring during the lifetime of a given test or service.
Corrosion Wear
Wear in which chemical or electrochemical reaction with the environment is significant.
Density
The mass per unit volume of a substance, usually expressed in grams per cubic centimeter or in pounds per cubic foot.
Fatigue
The loss of load-bearing ability of a material under repeated load application, as opposed to a single load.
Fatigue Limit (Endurance Limit)
Maximum stress that a material will endure without failure for an infinite number of load cycles.
Fatigue Strength
Maximum stress that a material will endure without failure for a specified number of load cycles.
Frictional Wear
The displacement and/or detachment of metallic particles from a surface as a consequence of being in contact with another moving component.
Hardness
Resistance of a material to indentation as measured by such methods as Brinell, Rockwell, and Vickers. The term hardness also refers to stiffness of a material, or its resistance to scratching, abrasion, or cutting.
Internal Friction
Ability of a metal to transform vibratory energy into heat; generally refers to low stress levels of vibration; damping has a broader connotation since it may refer to stresses approaching or exceeding yield strength.
Internal Stresses (or Thermal Stresses)
Generally stresses which occur during the cooling of a part.
Martensite
A generic term used for microstructures formed by diffusionless phase transformations. A constituent found in hardened steel; has a needle like microstructure.
Mass Effect
The effect that the mass of a component has on the properties of the material from which the part is made. In castings such effects may arise due to the effect of mass on the solidification and on the rate of temperature change heat treatment.
Metallographic Structure
The nature, distribution, and amounts of the metallographic constituents in a metal.
Microstructure
The structure of polished and etched metal and alloy specimens as revealed by the microscope at magnifications over 10 diameters.
Modulus Of Elasticity (E)
In tension it is the ratio of stress to the corresponding strain within the limit of elasticity (Yield Point) of a material. For carbon and low alloy steels any composition and treatment, the value is approximately 200 GPa or 30,000,000 psi.
Modulus of Resilience (ur)
The amount of strain energy per unit volume required to stress a material from zero to the yield stress limit. The modulus of resilience is proportional to the area under the elastic portion of the stress-strain diagram. Units are Pa or psi.
Modulus of Rigidity
In a torsion test the ratio of the unit shear stress to the displacement caused by it per unit length in the elastic range.
Modulus of Rupture
Used in both bending and torsion testing. In bending, the modulus of rupture is the bending moment at fracture divided by the section modulus. In torsion, modulus of rupture is the torque at fracture divided by the polar section modulus.
Modulus of Toughness (ut)
Amount of work per unit volume of a material required to carry that material to failure under static loading. Equal to the area under the entire stress-strain curve. Units are Pa or psi.
Sand Porosity
Volume of the pore spaces or folds in a sand. (Not synonymous with permeability).
Screen Analysis (Sieve Analysis)
Distribution of particle size sand expressed in terms of the percentage of weight retained on each of a series of standard screens decreasing in mesh size and the percentage passed by the screen of finest mesh.
Shear
A type of deformation in which parallel planes in the metal crystals slide so as to retain their parallel relation.
Shear Modulus (G)
In a torsion test, the ratio of the unit shear stress to the displacement caused by it per unit length in the elastic range. Units are Pa or psi.
Shear Strain
Elastic displacement produced by pure shear loading.
Shear Strength
Maximum shear stress a material is capable of withstanding without failure.
Shear Stress
Load per unit area parallel to the plane of contact.
Specific Gravity
A numerical value representing the weight of a given substance as compared with the weight of an equal volume of water at 3.9°C (39°F), for which the specific gravity is taken as 1,000 kg/m3.
Specific Heat
Equivalent to thermal capacity, or the quantity of heat required to produce a unit change in the temperature of a unit mass.
Specific Volume
Volume of one gram of a substance at a specific temperature, usually 20°C (68°F).
Standard Deviation
A statistical quantity used to describe the variation of a measurable attribute about some average value.
Structure (Cast Structure)
The size and disposition of the constituents of a metal as cast.
Surface Texture
The roughness, waviness, lay or other characteristics of the surface of a part.
Temper Brittleness
Brittleness that results when certain steels are held within or cooled slowly through a certain range of temperature below the transformation range. The brittleness is revealed by notched-bar impact tests at room temperature or lower temperatures.
Temper Stressing
Quenching in water from the tempering temperature to improve fatigue strength.
Temperature
Degree of warmth or coldness in relation to an arbitrary zero measured on one or more of accepted scales, as Centigrade, Fahrenheit, etc.
Tensile Strength
The maximum stress in uniaxial tension testing which a material will withstand prior to fracture. The ultimate tensile strength is calculated from the maximum load applied during the test divided by the original cross-sectional area.
Thermal Conductivity
The property of matter by which heat energy is transmitted through particles in contact. For engineering purposes, the amount of heat conducted through refractories is usually given in Btu per hour for one square foot of area, for a temperature difference of one degree Fahrenheit, and for a thickness of one inch, Btu/hr·ft·F/in.
Thermal Fatigue
Failure resulting from rapid cycles of alternate heating and cooling.
Thermal Shock
Stress developed by rapid and uneven heating of a material.
Thermal Stability
Resistance of a material to drastic changes in temperature.
Tolerance
The permissible deviation of a dimension from the nominal or desired value. Minimum clearance between mating parts.
Wear
The undesired deterioration of a component by the removal of material from its surface.