MODULE 2 (1.1) - FUNDAMENTALS OF FRICTION AND WEAR

Question 1

the science that deals with the study of friction, wear, and lubrication
of interacting surfaces in relative motion

Answer 1

Tribology

Question 2

from the Greek Word tribos , meaning “rubbing”

Answer 2

Tribology

Question 3

the Greek Word with meaning “rubbing”

Answer 3

tribos

Question 4

meaning of the Greek word tribos

Answer 4

rubbing

Question 5

Large mass

Answer 5

Macrotribology

Question 6

Heavy load

Answer 6

Macrotribology

Question 7

Wear

(Inevitable)

Answer 7

Macrotribology

Question 8

Bulk material

Answer 8

Macrotribology

Question 9

Small mass

(μg)

Answer 9

Micro/Nanotribology

Question 10

Light load

(μg to mg)

Answer 10

Micro/Nanotribology

Question 11

No wear

No wear (few atomic layers)

Answer 11

Micro/Nanotribology

Question 12

Surface

Surface (few atomic layers)

Answer 12

Micro/Nanotribology

Question 13

the resistance to movement of one body over another body

Answer 13

Friction

Question 14

from the Latin verb fricare, meaning “to rub”

Answer 14

Friction

Question 15

Latin verb meaning “to rub”

Answer 15

fricare

Question 16

meaning of the Latin verb fricare

Answer 16

to rub

Question 17

between contacting bodies, it is manifested as the forcé that must be overcome to initiate or sustain motion, and as the energy dissipated during relative motion

Answer 17

Friction

Question 18

the force needed to overcome the potential energy barriers between atoms in order to initiate sliding

Answer 18

Static Friction

Question 19

the mechanisms for dissipating energy as
atoms slide over each other

Answer 19

Kinetic Friction

Question 20

the impairment and damage of contacting surfaces due to adhesión, fatigue, abrasion, erosion, cavitation, oxidation, fretting, impact, melting and diffusion

Answer 20

Wear

Question 21

the provision of a separating fluid between contacting surfaces to reduce friction and wear

Answer 21

Lubrication

Question 22

First Law of Friction

Answer 22

Definition of Coefficient of Friction

(Amontons)

Question 23

F =

Answer 23

fW

Question 24

the frictional force is independent of the apparent area of contact

Answer 24

Second Law

(Amontons)

Question 25

once sliding stops, the force needed to initiate sliding (static friction) is greater than the force needed to sustain sliding (kinetic friction)

Answer 25

Second Law | (Amontons)

Question 26

kinetic friction is independent of sliding velocity

Answer 26

Third Law | (Coulomb)

Question 27

postulated in 1508 the concept of characteristic coefficient of friction as the ratio of frictional force to normal load

Answer 27

Leonardo Da Vinci | (Italy)

Question 28

established in 1699 the significance of a coefficient of friction, which is independent of the apparent area of contact

Answer 28

Guillaume Amontons | (France)

Question 29

distinguished in 1785 the difference between static and kinetic friction

Answer 29

Charles-Augustin de Coulomb | (France)

Question 30

developed an analytical model to describe abrasive wear leading to the Archard equation and the dimensionless wear coefficient 𝑘

Answer 30

John Archard | (UK)

Question 31

wood, stone, leather, iron and copper were commonly used as bearing materials through the years prior to the Industrial Age

Answer 31

Bearing Materials

Question 32

suggested in 1684 to use steel shafts/bell metal bushes in lieu of wood shod with iron for wheel bearings

Answer 32

Robert Hooke | (UK)

Question 33

patented in 1839 high lead and high tin alloys and was widely used in industrial, automotive and railway applications

Answer 33

Isaac Babbitt | (US)

Question 34

were introduced in 1900

Answer 34

tool steels

Question 35

were introduced in 1920's

Answer 35

porous metal bearings

Question 36

were used on chariot wheels as lubricant before 1400 BC

Answer 36

Tallow | (Animal Fat)

Question 37

were commonly used prior to the advance in the petroleum industry

Answer 37

vegetable oil

Question 38

opened in Titusville, Pennsylvania in 1859, ushering the modern petroleum industry

Answer 38

Drake well

Question 39

reached 9500𝑚3/𝑦𝑟 in the next 20 years after that "Drake Well"

Answer 39

Lubricant production

Question 40

to upgrade the properties and extend lives of lubricanting oils began in 1920

Answer 40

chemical additives

Question 41

studied in 1849 and 1854, respectively, shafts and bearings running in full hydrodynamic conditions

Answer 41

Friedrich August von Pauli (Germany) and Gustave Adolphe Hirn (France)

Question 42

found out in 1883 the principles of hydrodynamic phenomenon in fluid film bearing

Answer 42

Nikilay Petroff | (Russia)

Question 43

discovered in 1883 hydrodynamic lubrication experimentally and reported the generation of pressure in the oil film of a journal bearing

Answer 43

Beauchamp Tower | (UK)

Question 44

developed in 1886 a mathematical expression for this pressure build up in hydrodynamic lubrication

Answer 44

Osborne Reynolds | (UK)

Question 45

Advances in computation of the ________ built upon the works of Sommerfeld (Germany, 1904), Cameron/Wood (Canada/US, 1949) and Pinkus/Raimondi/Boyd (US, 1958) proved helpful on the evaluation of dynamic effects in fluid film lubrication

Answer 45

hydrodynamic phenomena

Question 46

the earliest ball bearing was developed in UK

Answer 46

1780

Question 47

ball bearings were used in bicycles

Answer 47

1868

Question 48

a patent for deep groove ball bearing with cage was awarded

Answer 48

1902

Question 49

a Swedish bearing manufacturer was founded

Answer 49

SKF