MODUE 3 Flashcards
denote the physical state of materials that are exclusive of their chemical or mechanical components.
physical properties
_____ implies the weight of a material, with higher _____ rates implying heavier materials.
Density
is the minimum required temperature for a solid material to change into liquid.
Melting point
_____ is the reflective property of a material.
Color
is the minimum required temperature for a liquid material to change into
gas.
Boiling point
Dimension of any metal reflect shape and size of material, length, width, height, depth etc.
Also, it determines specific rectangular, circular, spherical, or any other section.
Size and shape
It is defined as ratio of density of material with respect to density of reference material or
substance. It does not have any unite. Sometimes it is also called as relative density.
Specific Gravity of Materials
represents quantity of voids in solid materials.
Porosity of Materials
material reflects its response or deformation in relation to
an applied load or force.
Mechanical Properties
(ASTM), meaning
American Society for Testing and Materials
One of the
instruments used for conducting this stress strain test is the
Universal Testing Machine.
is defined as the instantaneous load divided by the original specimen cross-
sectional area.
stress
During this test, gradually increasing tensile load is applied uniaxially along the long axis
of a specimen.
Tension test
is conducted in a manner similar to the tensile test, except that the
force is compressive and the specimen contracts along the direction of the stress.
Compression Test
performed using a pure shear force,
shear test
is a variation of pure shear in which a structural member is twisted.
Torsion Test
Also known as transverse beam testing, it measures the behavior of materials subjected
to simple beam loading.
Flexural or Bending Test
is expressed as the change in length (in the
direction of load application) divided by the original length.
Engineering strain (ε)
is defined as the tangent of the strain angle θ while in
torsion, the shear strain is related to the angle of twist (ø)
shear strain(ɣ)
is the deformation in which stress and strain are proportional.
Elastic Deformation
It is defined as the ratio of the lateral and axial strains.
Poisson’s ratio (ν)
is the slope of the linear elastic region of the shear
stress–strain curve.
Shear modulus of elasticity
occur when the stress is removed, the material does not return to its previous dimension, it is a permanent, irreversible deformation.
Plastic deformation
can be determined using tensile testing.
Tensile properties
In this limit the ratio of stress with strain
gives us proportionality constant known as young’s modulus.
Proportional Limit
It is the point in the graph up to which the material returns to its original position when the
load acting on it is completely removed. Beyond this limit the material cannot return to its original
position and a plastic deformation starts to appear in it.
Elastic Limit
is defined as the point at which the material starts to deform plastically.
Yield point
After the _______ is passed there is permanent deformation develops in the
material and which is not reversible.
yield point
It is the point corresponding to the maximum stress that a material can handle before
failure.
Ultimate Stress/ Tensile Strength
Beyond
this point the failure takes place.
Ultimate Stress/ Tensile Strength
It is the point in the stress strain curve at which the failure of the material takes place.
Fracture or Breaking Point
is a property of a solid material which indicates that how easily a material gets
deformed under tensile stress.
Ductility
is often categorized by the ability of material to get stretched into a wire by pulling or drawing.
Ductility
opposite of brittleness.
Ductility
is the ability of material to ABSORB the energy when it is deformed elastically by
applying stress and release the energy when stress is removed.
Resilience
defined as the maximum energy that can be absorbed per unit volume without permanent
deformation.
modulus of resilience
It is the ability of material to absorb the energy and gets plastically deformed without
fracturing.
Toughness
Therefore,
to be tough,
material should be capable to withstand with both high stress and strain.
It is the ability of material to resist to permanent shape change due to external stress.
Hardness
is the ability of material to oppose the scratch to
outer surface layer due to external force.
Scratch Hardness
It is ability of material to oppose the dent due to punch of external
had and sharp object.
Indentation Hardness
is also called as dynamic hardness. It is
determined by the height of “bounce” of a diamond tipped hammer dropped from a fixed
height on the material.
Rebound Hardness
It is the ability of a material to attain the hardness by heat treatment processing.
Hardenability
indicates that how easily it gets fractured when it is subjected to
a force or load.
Brittleness
Brittleness
of material is ______ depended.
temperature
is property of solid material which indicates that how easily a material gets
deformed under compressive stress.
Malleability
is often categorized by the ability of material to
be formed in the form of a thin sheet by hammering or rolling.
Malleability
is the property of material which indicates the tendency of material to move slowly
and deform permanently under the influence of external mechanical stress.
Creep
is the weakening of material caused by the repeated loading of material.
Fatigue
is a measure of the acidity or basicity of a solution.
pH
Solutions with a pH less than 7 are
said to be
acidic
and solutions with a pH greater than 7 are said to be
basic or alkaline.
a low pH indicates
a high concentration of hydrogen ions,
high pH indicates
a low concentration of hydrogen ions
high pH indicates
a low concentration of hydrogen ions,
is the ability of a substance to attract and hold water molecules from the
surrounding environment through either absorption or adsorption
Hygroscopy
property of the surface of a liquid that allows it to resist an external
force.
Surface tension
is a material property of solids which measures the total surface
area per unit of mass, solid or bulk volume, or cross-sectional area.
Specific internal surface area
refers to the rate at which a chemical substance tends to undergo
a chemical reaction in time.
Reactivity
Some metals are more intrinsically resistant to corrosion than others, either due to the
fundamental nature of the electrochemical processes involved or due to the details of how
reaction products form.
Corrosion resistance
is a property that is
indicative of a material’s ability to absorb heat from the external surroundings; it represents the
amount of energy required to produce a unit temperature rise.
Heat capacity
often called simply specific heat, denoted by a lowercase c, which is
the heat capacity per unit mass of a material and has a various units of J/kg-K, cal/gK and
BTU/lbm
oF.
specific heat capacity,
which is the heat capacity per mole of a pure substance (J/mol-K)
molar heat capacity,
is a material property that is indicative of the extent to which a material
expands upon heating, and has units of reciprocal temperature.
Thermal expansion
is the property that characterizes the ability of a material to
transfer
Thermal conductivity
stresses induced in a body as a result of changes in temperature.
thermal stresses
how easily something will burn or ignite,
causing fire or combustion.
Flammability
is the lowest temperature at
which it will spontaneously ignite in a normal atmosphere without an external source of ignition,
such as a flame or spark.
The autoignition temperature or kindling point of a substance
is the energy required to transform a given quantity of a substance into a gas at a
given pressure (often atmospheric pressure).
Heat of vaporization
is the
change in enthalpy resulting from the addition or removal of heat from 1 mole of a substance to
change its state from a solid to a liquid (melting) or the reverse processes of freezing.
The enthalpy of fusion, also known as the heat of fusion or specific melting heat,
is the temperature at which the vapor pressure of the solid and
the liquid are equal.
melting point of a solid
is the lowest temperature at which it can vaporize to form an ignitable mixture in air.
Flash Point
Measuring a liquid’s flash point requires an
ignition source.
is the temperature at which a ferromagnetic or
a ferrimagnetic material becomes paramagnetic on heating; the effect is reversible.
Curie temperature (Tc), or Curie point,
relate the current (I) or time rate of charge passage to the applied voltage (V).
Ohm’s Law
indicative of the ease with which a material is capable of conducting
an electric current.
Electrical conductivity
Conductivity is the reciprocal (inverse) of
electrical resistivity,
is the reciprocal of electrical Conductivity.
Electrical resistivity
When a voltage is applied across a capacitor, one plate becomes positively charged and
the other negatively charged, with the corresponding electric field directed from the positive to the
negative plates.
Capacitance
is the measure of how much resistance is encountered when forming an
electric field in a medium.
Permittivity
is a measure of how an electric field affects,
and is affected by a dielectric medium.
permittivity
relates to a
material’s ability to transmit (or “permit”) an electric field.
permittivity
represents the increase in charge-storing capacity upon insertion
of the dielectric medium between the plates. The dielectric constant is one material property of
prime consideration for capacitor design. The value
Dielectric Constant
represents the
magnitude of an electric field necessary to produce breakdown.
Dielectric Strength
The group of dielectric materials called ferroelectrics exhibit spontaneous polarization—
that is, polarization in the absence of an electric field. They are the dielectric analogue of
ferromagnetic materials, which may display permanent magnetic behavior.
Ferroelectricity
is an unusual phenomenon exhibited by a few ceramic materials (as well
as some polymers).
Piezoelectricity
is the measure of charge which accumulates in certain solid
materials (notably crystals, certain ceramics, and biological matter such as bone, DNA and
various proteins) in response to applied mechanical strain.
Piezoelectric constant
the phenomenon by which materials exert an attractive or repulsive force or
influence on other materials.
Magnetism
may be thought of as small bar magnets
composed of north and south poles instead of positive and negative electric charges.
Magnetic dipoles
is the externally applied magnetic field.
Magnetic field strength
represents the MAGNITUDE of the internal field
strength within a substance that is subjected to an H field.
Magnetic flux density or magnetic induction
is a property of the specific medium through which the H field passes and in
which B is measured.
Permeability
is a very weak form of magnetism that is nonpermanent and persists only
while an external field is being applied.
Diamagnetism
For some solid materials, each atom possesses a permanent dipole moment by virtue of
incomplete cancellation of electron spin and/or orbital magnetic moments. In the absence of an
external magnetic field, the orientations of these atomic magnetic moments are random, such that
a piece of material possesses no net macroscopic magnetization. These atomic dipoles are free
to rotate, and paramagnetism results when they preferentially align, by rotation, with an external
field.
Paramagnetism
Certain metallic materials possess a permanent magnetic moment in the absence of an
external field and manifest very large and permanent magnetizations.
Ferromagnetism
are a material’s response to exposure to electromagnetic radiation and,
in particular, to visible light.
Optical properties
is considered to be wavelike, consisting of electric and magnetic
field components that are perpendicular to each other and also to the direction of propagation
Electromagnetic radiation
expressed in watts per square meter, corresponds to the energy being
transmitted per unit of time across a unit area that is perpendicular to the direction of propagation
Radiation intensity
Materials that are capable of transmitting light with relatively little absorption and reflection,
one can see through them.
Transparent
Materials are those through which light is transmitted diffusely; that is, light is scattered
within the interior to the degree that objects are not clearly distinguishable when viewed through a specimen of the material.
Translucent
Materials that are impervious to the transmission of visible light.
Opaque
When light passes from one transparent medium to another having a different index of
refraction
Reflection
may occur by the promotion or excitation of an electron
from the nearly filled valence band, across the band gap, and into an empty state within the conduction band.
Absorption
The phenomena of absorption, reflection, and transmission may be applied to the passage
of light through a transparent solid.
Transmission
is the phenomenon in which light that is transmitted into the interior of
transparent materials experiences a decrease in velocity, and, as a result, is bent at the interface.
Refraction
