Midterm

Question 1

STRENGTH

Answer 1

The ability of a material to withstand stress (pressure, force) without failure

Question 2

HARDNESS

Answer 2

The ability of a material to resist to scratching, abrasion, cutting,
indentation, or penetration. ( Knoop, Vickers, Rockwell, Brinell)

Question 3

TOUGHNESS;

Answer 3

The ability of a material to absorb energy and plastically deform without
fracturing

Question 4

STIFFNESS (Rigidity)

Answer 4

The ability of material to resist deformation or withstand bending

Question 5

DUCTILITY

Answer 5

The ability to deform under tensile load without rupture

Question 6

BRITTLENESS

Answer 6

The breaking or shattering of a material when subjected to stress (when
force is applied to it)

Question 7

ELASTICITY;

Answer 7

The ability of material to returns to its original shape after stress removed

Question 8

PLASTICITY

Answer 8

The ability of material to non-reversible changes of shape after stress
removed

Question 9

The maximum stress that any material will withstand before destruction is
called

Answer 9

Ultimate strength

Question 10

Mechanical behavior

Answer 10

the microstructure and the mechanical properties

Question 11

The area under the stress-strain curve

Answer 11

Toughness

Question 12

When do many types of steel become brittle?

Answer 12

Lower temperatures

Question 13

Increasing temperature, increases ductility?

Answer 13

True

Question 14

Gold is the most malleable metal

Answer 14

True

Question 15

Malleability

Answer 15

is the ability of material to deform under

rolling or hammering without fracture ( think of an aluminum plate)

Question 16

Fatigue

Answer 16

Cyclic stresses

Question 17

The more strain a material can go through the more ductile it is

Answer 17

True

Question 18

Strain

Answer 18

The ratio of elongation to the original length

Question 19

Tensile strain

Answer 19

• Ratio of increase in length to original length of

the body when it is subjected to a pull force

Question 20

Compressive strain

Answer 20

Ratio of decrease in length to original

length of the body when it is subjected to a push force

Question 21

Volumetric strain

Answer 21

Ratio of change of volume of the body to the

original volume

Question 22

Elastic deformation

Answer 22

where stress and strain are proportional

Question 23

The greater the elastic modulus, the

Answer 23

stiffer the material

Question 24

strain hardening

Answer 24

x-sectional area will decrease

Question 25

necking

Answer 25

localized area will decrease

Question 26

Poissons ratio

Answer 26

ratio of transverse contraction to longitudinal strain

Question 27

increasing Temperature will decrease Everything but ductility

Answer 27

True

Question 28

Higher than critical temperature, cooling slowly

Answer 28

annealing

Question 29

higher than critical temperature, cooling rapidly

Answer 29

hardening

Question 30

Alloying is a thermal treatment

Answer 30

True

Question 31

Tempering

Answer 31

Steel is heated below the critical temperature and cooled slowly

Question 32

The strength to weight and stiffness to weight ratio depends on

Answer 32

density

Question 33

Thermal expansion along with thermal conductivity are the most significant reasons behind

Answer 33

thermal stresses

Question 34

The coefficient of thermal expansion is inversely proportional to the melting point

Answer 34

True

Question 35

Specific strength and stiffness are important for materials that operate in high temperatures

Answer 35

True

Question 36

Conductivity is a physical property

Answer 36

True

Question 37

Example of case hardened diffusion is case hardened steel

Answer 37

True

Question 38

Negative means from higher to lower in ficks law

Answer 38

True