Various surface engineering technique for prevention of wear resistance have been discussed.

1. Course Instructor:Dr.Debasish Sarkar
Department Of Ceramic Engineering
NIT Rourkela,Sundergarh,Odissa,769008
Submitted by: Suman yadav
(118CR0802)

2. What does Surface Engineering means
• To mold the surface properties to improve their
functionality and service.
• This includes improvement in terms of corrosion
resistance,oxidation,wear resistance,mechanical,electrical
and thermal properties.
The several ways of improvement of these properties are
obtained through metallurgically,mechanically,chemically or
adding coating.

3. WHAT IS THE NEED FOR SURFACE
ENGINEERING
Waste of huge amount of
metallurgical material on annual
basis leads to huge economic
loss.
Progressive deterioration as a
result of wear leads to shut down
of various industrial plants.

4. Surfaces
Surface may be defined as interface between two phases or two grains in same phase.
Why is Surface important
It is the region of a highest energy
◦ It faces the environment
◦ It’s the part of the component where stresses are often highest.
Surface Energy
◦ Surface posses some extra energy due to the work done to create it.
◦ Surface Energy have a significant influence on friction and wear,atomic arrangement of surface atoms,corrosion behavior

5. Wear
Progressive loss of material from the metal surface due to relative motion between the surface and a
contacting substance.
Friction
Friction is defined as the resistance against movement of a body.
Laws of friction
◦ Static friction may be greater than kinetic friction.
◦ Friction is independent of sliding body.
◦ Friction force is proportional to applied load.
◦ Friction force is independent of contact area.

6. WEAR
Abrasion
Erosion
Adhesion
Surface Fatigue

7. Abrasion wear
It is defined as the wear because of hard particles or hard protuberances forced against and moving
along the solid surface.
Adhesive wear
Wear due to localized bonding between contacting solid surfaces leading to materials transfer
between the two surfaces or the loss from either surface.
Erosion
Removal of material from a surface due to mechanical interaction between that surface and a fluid,
a multicomponent fluid,or impinging liquid or solid particles.
Fatigue wear
Fracture of material from a solid surface caused by cyclic stresses produced by repeated rolling or
sliding on a surface.

8. Surface Engineering
Modification(Surface dimension
unchanged)
Removal(Cleaning/Polishing) Addition(Deposition/Coating)
Microstructure
Composition
Mechanical
Electro-chemical
Chemical
Chemical
Physical
Electro-chemical

9. Modification based Surface Engineering Methods
◦ Annealing
◦ Surface Hardening
◦ Induction hardening
◦ Short peening
◦ Diffusion Coating
◦ Ion-beam Implantation
◦ Chemical reaction based modification

10. Removal Based Surface Engineering Methods
◦ Rubbing/polishing
◦ Grinding/polishing
◦ Electro-chemical polishing
◦ Electro-discharge machining
◦ Dip cleaning
◦ Chemical polishing
◦ Etching-uniform/selective

11. Addition based Surface Engineering Methods
◦ Galvanizing
◦ CVD
◦ PVD
◦ Plasma spray/deposition
◦ Thermal spray
◦ Sputtering
◦ Electro-deposition

12. Surface Hardening
Surface hardening is a surface engineering method to harden steel components upto certain depth from surface
by thermal or mechanical means without affecting the core.
Combination of hard surface and soft interior is very useful to prevent damage due to high stress and fatigue.
Following surface hardening mechanism falls under the category:
◦ Flame hardening or Induction hardening
◦ Electrolytic surface hardening
◦ Carburizing
◦ Nitriding

13. Flame hardening
Flame hardening system comprises oxy-fuel torch to heat(mostly oxygen with acetylene as fuel gas),a system for
rapid quenching and an arrangement to move the stage/workpiece or the heat source.
Carburizing
Carburizing is a case hardening process in which carbon is dissolved in the surface layers of a low-carbon steel
part at a temperature sufficient to render the steel austenitic,followed by quenching and tempering to form a
martensitic microstructure.
Nitriding
Nitriding is a process to enrich the surface of steel with interstitial nitrogen at elevated temperatures.
Reaction of nitrogen with steel causes the formation of very hard iron+ nitrogen interstitial compounds.

14. Coating Techniques
-Diffusional Coating(Al,Si,Cr)
-Conversion Coatings(oxidizing,anodizing)
-Thernal Coatings(carburizing-flame Spraying)
-Metal Coatings(electrochemical,electro-less)
-Deposition (PVD,CVD)
-Organic Coatings(painting,lacquer)
Diffusional Coating
Diffusion coating is a process in which metal
components that will be subjected to high
temperature conditions and highly corrosive
environments are coated with a non-
corrosive material.

15. Physical Vapor Deposition(PVD)
◦ PVD is a process of depositing thin films of elemental metal or metallic/ceramic compound overall engineering
solids.
◦ Deposit is made by thermal evaporation of target.
Chemical Vapor Deposition(CVD)
◦ CVD involves formation of non-volatile thin solid film by reaction of ions/species in the vapor state and
subsequent deposition.
◦ Reactant gases decompose and react on heated surface to form thin film.

16. THANK YOU