Lab 2. Impact Test-Charpy

Question 1

impact test

Answer 1

measures the energy absorbed up to fracture upon rapid loads

it is also an indication of toughness, it tells you how resistive your sample is to impact

Question 2

elastic deformation

Answer 2

temporary change in the shape of a material when a load is applied. the object returns to its original shape on removal of the load

Question 3

plastic deformation

Answer 3

this type of deformation is not reverisible. in the this case, the material retains the deformed shape even after the removal of the load

Question 4

ductile materials

Answer 4

ductile materials experience significant plastic deformation before fracture

Question 5

brittle materials

Answer 5

they show little or no plastic deformation before fracture

Question 6

toughness

Answer 6

measure of the ability of a material to absorb energy up to fracture

Question 7

static toughness

Answer 7

low strain rate, tensile test

Question 8

dynamic toughness

Answer 8

high strain rate. ability of a material to absorb energy under sudden forces and shocks-impact test

Question 9

stress-strain diagram

Answer 9

is a plot of the stress on the (y-axis) versus the strain on the x axis

Question 10

ductile fracture

Answer 10

cracks move slowly and are accompanied by a large amount of plastic deformation

Question 11

brittle fracture

Answer 11

cracks move more rapidily through a stressed material. the cracks usually travel so fast taht failure occurs without warning. In other words, there is very little plastic deformation before failure occurs

Question 12

tough material

Answer 12

HIGH ductility under high stress value… resistive to fracture under static loads

Question 13

ductile material

Answer 13

high strain, withstand dynamic and static loads. FCC

Question 14

BCC metals

Answer 14

inconsistency between tensile test results and impact test result

a BCC material showing ductile behavior in tensile test and high toughness can exhibit brittle behavior in impact test. this is expecially seen under room temperature

Question 15

dislocation

Answer 15

bond breaking and reforming

Question 16

mechanism of crack propagtion

Answer 16

in a material is the way in which the advancing crack travels through the sampleq

Question 17

for ductile materials

Answer 17

the mechanism is microvoids

Question 18

for brittle materials

Answer 18

are transgranular or intergranular fracture

Question 19

microvids

Answer 19

nucleate at inclusions and second-phase particle. . the viods grow together to form a crack

Question 20

transgruanular fracture

Answer 20

the fracture travels through the grain of the material

Question 21

intergranular fracture

Answer 21

in the this case, the crack travels along the grain boundaries and not through the actual grains. cracks choose the path of least resistance

Question 22

Impact testing

Answer 22

an objects ability to resist high-rate loading

Question 23

charpy impact test

Answer 23

is standarized high strain-rate test wich determines the amount of energy absorbed by a material during fracture

Question 24

impact energy

Answer 24

measured by the charpy test is the work done to rapture the specimen

Question 25

this absorbed energy is the measure of given material’s

Answer 25

toughness

Question 26

impact testing

Answer 26

measures an object’s ability to resist high rate loading

Question 27

the charpy impact test

Answer 27

is the standarized high strain-rate test which determines the amount of energy absorbed by a amaterial during fracture

Question 28

the impact energy

Answer 28

measured by the charpy test is the work done to rapture the specimen

Question 29

the abosorbed energy is measured of a given material’s

Answer 29

toughness