materials

Question 1

what is yield strength?

Answer 1

Yield Strength: the stress at which permanent deformation begins. graph becomes non linear

Question 2

what is ultimate tensile strength?

Answer 2

Ultimate Tensile Strength: The highest stress resisted by a material

Question 3

what is breaking strength?

Answer 3

Breaking Strength: The stress at which a material fails by fracture

Question 4

what is plastic deformation?

Answer 4

permanent deformation that remains when the load is removed.

Question 5

can plastic deformation occur in brittle materials?

Answer 5

no

Question 6

what’s a ductile material?

Answer 6

Materials that readily plastically deform

Question 7

what’s a brittle material?

Answer 7

Materials that don’t plastically deform

Question 8

what is hardness?

Answer 8

Hardness: A measure of resistance to
permanent (or plastic) deformation

Question 10

testing for hardness

Answer 10

Commonly measured by indentation testing

Question 11

do brittle materials tend to have low or high hardness?

Answer 11

high

Question 12

do ductile materials tend to have low or high hardness?

Answer 12

low

Question 13

what is stiffness?

Answer 13

Stiffness: the extent of elastic deformation in response to an applied load

Question 14

what’s Youngs modulus?

Answer 14

Young’s Modulus: the material property that defines stiffness – derived from stress and strain relationship

Question 15

what’s electronegativity?

Answer 15

the tendency for an atom to attract additional electrons

Question 16

strongest bonds- primary or secondary

Answer 16

primary

Question 17

ionic bonding

Answer 17

formed between metals (lose electrons) and non metals (gain electrons) due to electrostatic attraction

Question 18

metallic bonding

Answer 18

delocalised electrons create a ‘sea’ around metal cations allowing electrical conductivity

Question 19

covalent bonding

Answer 19

atoms share electrons to fill valence shells forming directional bonds