Property
Definition
Calculation
Tests
Use in design
Relationship to other
properties
Relationship to
Bonding
Mechanical
Properties that have to do with a
reaction to an applied load
Ductility
The measure of the degree of
plastic deformation at fracture
Percent elongation
%EL = (lf-lo/lo)x100
Percent reduction
in area
%RA = (A0-Af/A0)
Tensile strength
test
Used in manufacturing to know
what materials can be machined
in specific ways, and used in
buildings when complete failure
would have devastating results
(think plastic deformation during
earthquakes)
Brittleness: lack of
ductility
Metallic bonding
provides the best
ductility
Modulus of
elasticity
Quantifies a material's
resistance to elastic deformation
E = stress/strain in
the elastic region of
a stress-strain
curve
Tensile strength
test
Used to determine how much a
material will deform under a
certain load
The higher the E the
higher the stiffness.
Higher interatomic
bonding, higher E
value
Yield
Strength
(tension)
The stress at which noticeable
plastic deformation starts to
occur.
The intersection of
0.2 offset and a line
drawn parallel to
the slope (E) of a
stress-strain curve
Tensile strength
test
Used to determine the max load
that will produce only elastic
deformation
Used to determine
Resilience
Ultimate
Tensile
Strength
The max stress that occurs
during plastic deformation
The highest point
on a stress-strain
curve
Tensile strength
test
Used when working with brittle
materials as they have no yield
point
Used to determine the
toughness
Poisson’s
Ratio
A ratio of deformation of the
width of a material and the
length
v = -(εxx/εzz)
Tensile strength
test
Used to determine stress and
For isotropic materials
deflection properties of materials 𝐺 = 𝐸
2(1+𝑣)
The capacity of a material to
The area under the
Resilience
𝐾=
Tensile strength
Resilient materials have high
𝐸
3(1−2𝑣)
Modulus of resilience
Stronger bonds lead to
lower poission ratios
absorb energy when deformed
elasticity, and then, upon
loading, to have this energy
recover
stress-strain curve
up to yield strain
Materials resistance to fracture
when a crack
(stress-concentrating defect) is
present. (fracture toughness)
Or
Ability of a material to absorb
energy and plastically deform
before fracturing. (notch
toughness)
Area under the
stress-strain graph
up until fracture
Hardness
Materials resistance to localized
plastic deformation
Thermal
Properties
Properties related to change in
temperature in and across
materials
Heat
Capacity
Thermal
Shock
resistance
Toughness
test
yield stress and low modulus of
elasticity and are good for
springs
Uf
Tensile strength
test
Used becasue it is almost
impossible and costly to
manufacture a piece without
defects
Metals: must display
both strength and
ductility
Through test
-Rockwell
Hardness test
- Brinell
Hardness test
-Knoop and
Vickers
Microindentation
Hardness test
Easy and inexplensive, tests are
non-destructive, and other
properties can be estimated
Tensile strength
TS(MPa) = 3.45xHB
TS(psi) = 500xHB
The ability of a material to
absorb heat from it’s
surroundings
Through tests
Calorimetry
Used to select materials for
temperature control of
environments
Specific heat
The ability of a material to resist
fraction when exposed to
extreme temperature changes
Based on other
material properties
Thermal shock
resistance test
Used when selecting materials
for use in extreme environment
Thermal Conductivity
ε𝑦
Ur = ∫ σ𝑑ε
0
ε𝑏
𝑡𝑜𝑢𝑔ℎ𝑛𝑒𝑠𝑠 = ∫ σ𝑑ε
0
Stronger bonds
produce higher
hardness
Higher in metallic
bonding
Thermal
Conductivity
The ease of which energy can
move through a material
Based on material
constants and
geometry
N/A
Needed for determining
conductive materials
Electrical conductivity
is the same in metals
Needs a see of
electrons to be high