ArulmiguMeenakshi Amman College of Engineering
Vadamavandal-604410.
Important questions and answers
CME397-SURFACE ENGINEERING
Prepared by
V.Umapathy,
Prof. /Mech.
S.No. Questions and answers
Unit-I
SURFACES AND FRICTION
2 – marks question and answers
1. What is the friction between surfaces?
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements
sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal an incomplete
list.
2. What are the types of surface?
They are divided into minimal surfaces, ruled surfaces, non-orientable surfaces, quadrics, pseudospherical
surfaces, algebraic surfaces, and other types of surfaces.
3. What are roughness parameters?
Surface roughness is a quantitative value that reflects the smoothness or roughness of the surface, which is
usually represented by the roughness parameter Ra, which is calculated as roughness average of a surfaces
measured microscopic peaks and valleys [60].
,4. What are RA and RZ in surface roughness?
Ra and Rz are both parameters used to describe the roughness of a surface. Ra, or average roughness, is the
average of all the peaks and valleys in a surface. Rz, or mean roughness depth, is the average distance
between the highest and lowest peaks and valleys.
5. What are the different types of roughness?
Surface roughness is a measure of the small irregularities on a surface. It can be characterized by different
types of roughness, including:
1. Waviness: A coarser irregularity that can cause a surface to warp or deflect
2. Absolute roughness: The average difference between peaks and valleys, also known as the
Arithmetic Average Roughness
3. Root mean square roughness : The root mean square of a surface's peaks and valleys
4. Lay: The dominant pattern on a surface, including its orientation.
6. What is a surface measurement?
Surface measurement, also known as surface metrology – refers to the measurement of topography or
surface roughness of precision surfaces. Surface roughness and the details of the surface profile determine
, the performance and appearance of many products.
7. What are the causes of friction?
Friction is caused due to the irregularities on the two surfaces in contact. So, when one object moves over
the other, these irregularities on the surface get entangled, giving rise to friction. The more the roughness,
the more irregularities and more significant will be the friction.
8. What is the static friction?
Static friction is the force that prevents objects from moving when they are touching and at rest. It's the
friction between an object and the surface it's on.
9. What is the stick-slip phenomenon?
Slip-stick: Slip-stick, also called stick-slip, is a phenomenon in which a spontaneous jerking motion occurs
when two objects slide over each other.
10. What are the properties of nonmetals?
Nonmetals are elements that typically lack the physical and chemical properties of metals. They have many
properties, including:
1. Poor conductors: Nonmetals are poor conductors of heat and electricity.
2. Brittle: Solid nonmetals are usually brittle.
3. Luster: Nonmetals have little or no metallic luster.
4. Electronegative: Nonmetals have high electronegativities.
5. Ionization energies: Nonmetals have high ionization energies.
6. Gain electrons: Nonmetals can easily gain electrons.
, 7. Chemical properties: Nonmetals have a wide range of chemical properties and reactivities.
8. Acidic oxides: Nonmetals form acidic oxides when they come into contact with oxygen.
9. Oxidizing agents: Nonmetals are great oxidizing agents.
13 and 15 marks question and answers
11. Explain with neat sketch Roughness parameters.
Surface roughness parameters are quantitative values that describe the smoothness or roughness of a
surface. They are used to evaluate the unevenness of a surface.
Height parameters
Vadamavandal-604410.
Important questions and answers
CME397-SURFACE ENGINEERING
Prepared by
V.Umapathy,
Prof. /Mech.
S.No. Questions and answers
Unit-I
SURFACES AND FRICTION
2 – marks question and answers
1. What is the friction between surfaces?
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements
sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal an incomplete
list.
2. What are the types of surface?
They are divided into minimal surfaces, ruled surfaces, non-orientable surfaces, quadrics, pseudospherical
surfaces, algebraic surfaces, and other types of surfaces.
3. What are roughness parameters?
Surface roughness is a quantitative value that reflects the smoothness or roughness of the surface, which is
usually represented by the roughness parameter Ra, which is calculated as roughness average of a surfaces
measured microscopic peaks and valleys [60].
,4. What are RA and RZ in surface roughness?
Ra and Rz are both parameters used to describe the roughness of a surface. Ra, or average roughness, is the
average of all the peaks and valleys in a surface. Rz, or mean roughness depth, is the average distance
between the highest and lowest peaks and valleys.
5. What are the different types of roughness?
Surface roughness is a measure of the small irregularities on a surface. It can be characterized by different
types of roughness, including:
1. Waviness: A coarser irregularity that can cause a surface to warp or deflect
2. Absolute roughness: The average difference between peaks and valleys, also known as the
Arithmetic Average Roughness
3. Root mean square roughness : The root mean square of a surface's peaks and valleys
4. Lay: The dominant pattern on a surface, including its orientation.
6. What is a surface measurement?
Surface measurement, also known as surface metrology – refers to the measurement of topography or
surface roughness of precision surfaces. Surface roughness and the details of the surface profile determine
, the performance and appearance of many products.
7. What are the causes of friction?
Friction is caused due to the irregularities on the two surfaces in contact. So, when one object moves over
the other, these irregularities on the surface get entangled, giving rise to friction. The more the roughness,
the more irregularities and more significant will be the friction.
8. What is the static friction?
Static friction is the force that prevents objects from moving when they are touching and at rest. It's the
friction between an object and the surface it's on.
9. What is the stick-slip phenomenon?
Slip-stick: Slip-stick, also called stick-slip, is a phenomenon in which a spontaneous jerking motion occurs
when two objects slide over each other.
10. What are the properties of nonmetals?
Nonmetals are elements that typically lack the physical and chemical properties of metals. They have many
properties, including:
1. Poor conductors: Nonmetals are poor conductors of heat and electricity.
2. Brittle: Solid nonmetals are usually brittle.
3. Luster: Nonmetals have little or no metallic luster.
4. Electronegative: Nonmetals have high electronegativities.
5. Ionization energies: Nonmetals have high ionization energies.
6. Gain electrons: Nonmetals can easily gain electrons.
, 7. Chemical properties: Nonmetals have a wide range of chemical properties and reactivities.
8. Acidic oxides: Nonmetals form acidic oxides when they come into contact with oxygen.
9. Oxidizing agents: Nonmetals are great oxidizing agents.
13 and 15 marks question and answers
11. Explain with neat sketch Roughness parameters.
Surface roughness parameters are quantitative values that describe the smoothness or roughness of a
surface. They are used to evaluate the unevenness of a surface.
Height parameters
