Chapter-2-summary-FAIRES (machine design elements)

Question 1

also known as precipitation hardening. It is a heat treatment technique which occurs in certain stainless steel, aluminum and copper alloys. At ambient temperature of metals results in a metal’s increased strength and hardness at the cost of its ductility.

Answer 1

Age hardening

Question 2

a substance with metallic properties, composed of two or more elements of which at least one is a metal.

Answer 2

Alloy

Question 3

usually considered as metallic elements added for modifying the properties.

Answer 3

Alloying elements in steel

Question 4

the characteristic of exhibiting different properties when tested in different directions (as tensile strength “with the grain” or “across the grain”).

Answer 4

Anisotropy

Question 5

a tendency to fracture without appreciable deformation

Answer 5

Brittleness

Question 6

a test which the energy absorbed in breaking the specimen is measured as the impact strength of the specimen. The specimen is supported at both ends.

Answer 6

Charpy test

Question 7

brittleness of metals at ordinary or low temperatures.

Answer 7

Cold shortness

Question 8

the process of deforming a metal plastically at a temperature below the recrystallization temperature and at a rate to produce strain hardening. Cold-drawn steel is frequently used because it enhances strength, machinability, and surface finish while reducing ductility.
Typically, steel undergoes 10-20% cold working for commercial purposes.

Answer 8

Cold working

Question 9

the ability of a material to absorb vibrations by converting its kinetic energy to heat through hysteresis. At a particular stress level, cast iron is a much better damping material than steel.

Answer 9

Damping Capacity

Question 10

a loss of carbon from the surface of steel when the
surrounding medium reacts with the carbon (as oxygen and carbon combining) which occurs during hot rolling, forging and heat treating.

Answer 10

Decarburization

Question 11

the property that permits permanent deformation before fracture in tension. It is stated that the higher the indices, percentage elongation and percentage reduction of area, the more ductile the material. Although ductility is the opposite of brittleness, there is no distinct boundary. Instead, it can be assumed as:

Ductile material Elongation > 5% in 2-in. gage.

Brittle material Elongation < 5%
in 2-in. gage.

Answer 11

Ductility

Question 12

ability of a material to be
deformed and return to its original shape.

Answer 12

Elasticity

Question 13

involves the loss of ductility because of a physical or chemical change of the material.

Answer 13

Embrittlement

Question 14

part of the carbon content of steel or iron that is in the form
of graphite or temper carbon.

Answer 14

Free carbon

Question 15

is a temper produced in a wire, rod, or tube by cold drawing.

Answer 15

Hard drawn

Question 16

materials that have the same structure at all points.

Answer 16

Homogenous materials

Question 17

materials that have the same properties in all directions.

Answer 17

Isotropic materials

Question 18

a test which the energy absorbed in breaking the specimen is measured as the impact strength of the specimen. The specimen is supported at one end as a cantilever

Answer 18

Izod test

Question 19

steel that has been deoxidized with a strong deoxidizing agent (silicon or aluminum) in order to eliminate a reaction between the carbon and the oxygen during solidification.

Answer 19

Killed steel

Question 20

a term used to describe how easy it is to cut a material.

Answer 20

Machinability

Question 21

the material’s susceptibility to extreme deformation through rolling or hammering. The more malleable the material is, the thinner the sheet into which it can be formed. Examples:
o Gold
o Aluminum

Answer 21

Malleability

Question 22

refers to the material’s characteristics concerning
stress and strain. Ultimate strength and percentage elongation are examples.

Answer 22

Mechanical properties

Question 23

extension in the vicinity of the fracture of a tensile specimen, express as a percentage of the original area.

Answer 23

Percentage elongation

Question 24

the smallest area at the point of rupture of a tensile specimen divided by the original area.

Answer 24

Percentage reduction area of area

Question 25

properties such as density, conductivity and coefficient of
thermal expansion.

Answer 25

Physical properties

Question 26

ability of a metal to be deformed without rupture. In a plastic deformation, the material does not return to its original shape.

Answer 26

Plasticity

Question 27

the ratio of the lateral strain (contraction) to the longitudinal strain (extension) when the element is loaded with a longitudinal tensile force.

Answer 27

Poisson’s ratio

Question 28

also called artificial aging, is the precipitation of a constituent from a supersaturated solid solution by holding the body at an elevated temperature.

Answer 28

Precipitation heat treatment

Question 29

the stress which causes a specified permanent deformation of a material. Usually, 0.01% or less.

Answer 29

Proof stress

Question 30

is a brittleness in steel when it is red hot.

Answer 30

Red shortness

Question 31

are those not due to applied loads or temperature gradients.
Exists for various reasons; as unequal cooling rates, cold working and etc.

Answer 31

Residual stresses

Question 32

incompletely deoxidized steel. Has a surface layer free of slag inclusions and gas pockets resulting to optimum surface on rolled sheets.

Answer 32

Rimmed steel

Question 33

a process of holding an alloy at a suitably high temperature long enough to permit one or more constituents to pass into solid solution and then cooling fast enough to hold the constituents as a supersaturated solution.

Answer 33

Solution heat treatment

Question 34

the ability of the materials to resist deformation.

o Higher modulus = stiffer material.

Answer 34

Stiffness

Question 35

increasing the hardness and strength by plastic deformation at temperatures lower than the recrystallization range.

Answer 35

Strain hardening

Question 36

a condition produced in a non-ferrous metal through mechanical or thermal treatment

Answer 36

Temper

Question 37

the capacity of a materials
to withstand a shock load without breaking.

Answer 37

Toughness

Question 38

frequently applied to brittles materials, it is the result of a transverse bend test to which the specimen is mounted as a simple beam. Also known as rupture modulus.

Answer 38

Transverse strength

Question 39

the same as strain hardening

Answer 39

Work hardening

Question 40

steel that has been hammered, rolled or drawn in the process of manufacture.

o Plain carbon
o Alloy steel.

Answer 40

Wrought steel