Midterm Flashcards
Mechanical Properties, Properties of Materials, Diffusion, Imperfection of Solids
STRENGTH
The ability of a material to withstand stress (pressure, force) without failure
HARDNESS
The ability of a material to resist to scratching, abrasion, cutting,
indentation, or penetration. ( Knoop, Vickers, Rockwell, Brinell)
TOUGHNESS;
The ability of a material to absorb energy and plastically deform without
fracturing
STIFFNESS (Rigidity)
The ability of material to resist deformation or withstand bending
DUCTILITY
The ability to deform under tensile load without rupture
BRITTLENESS
The breaking or shattering of a material when subjected to stress (when
force is applied to it)
ELASTICITY;
The ability of material to returns to its original shape after stress removed
PLASTICITY
The ability of material to non-reversible changes of shape after stress
removed
The maximum stress that any material will withstand before destruction is
called
Ultimate strength
Mechanical behavior
the microstructure and the mechanical properties
The area under the stress-strain curve
Toughness
When do many types of steel become brittle?
Lower temperatures
Increasing temperature, increases ductility?
True
Gold is the most malleable metal
True
Malleability
is the ability of material to deform under
rolling or hammering without fracture ( think of an aluminum plate)
Fatigue
Cyclic stresses
The more strain a material can go through the more ductile it is
True
Strain
The ratio of elongation to the original length
Tensile strain
- Ratio of increase in length to original length of
the body when it is subjected to a pull force
Compressive strain
Ratio of decrease in length to original
length of the body when it is subjected to a push force
Volumetric strain
Ratio of change of volume of the body to the
original volume
Elastic deformation
where stress and strain are proportional
The greater the elastic modulus, the
stiffer the material
strain hardening
x-sectional area will decrease
necking
localized area will decrease
Poissons ratio
ratio of transverse contraction to longitudinal strain
increasing Temperature will decrease Everything but ductility
True
Higher than critical temperature, cooling slowly
annealing
higher than critical temperature, cooling rapidly
hardening
Alloying is a thermal treatment
True
Tempering
Steel is heated below the critical temperature and cooled slowly
The strength to weight and stiffness to weight ratio depends on
density
Thermal expansion along with thermal conductivity are the most significant reasons behind
thermal stresses
The coefficient of thermal expansion is inversely proportional to the melting point
True
Specific strength and stiffness are important for materials that operate in high temperatures
True
Conductivity is a physical property
True
Example of case hardened diffusion is case hardened steel
True
Negative means from higher to lower in ficks law
True
