2. PREPARED BY:-
MAYANK H. PAL
5TH SEM MECH.ENGG.
(136120319528)
Topic-:Super Finishing Processes
Mechanical Department
Div.- C
3. WHY SUPER FINISHING REQUIRED
PARTS WORN OUT FAST DUE TO DEFECTS OF GRINDING OPERATION. THE
DEFECTS ARE CHATTER MARKS, HELICAL TYPE SCRATCHES, SURFACE
CRACKS, SMEAR METAL ETC. ARE RESPONSIBLE FOR WEARING OUT THE
PARTS. IN CERTAIN CIRCUMSTANCES HIGH SURFACE QUALITY IS
REQUIRED. HENCE FOR REMOVING GRINDING DEFECTS, TO OBTAIN
DESIRED SURFACE FINISH AND TO IMPROVE THE GEOMETRICAL SHAPE
FINISHING PROCESSES ARE USED. IT INCLUDES HONING, LAPPING, AND
SUPER FINISHING.
4. • TYPES OF SUPER FINISHING
PROCESS
Honing
Lapping
- Hand Lapping
- Machine Lapping
Super Finishing
5. • HONING
Hole made by boring is obtained to
required dimension and finishing by
honing. In this process abrasive stone is
used. The dimension to an accuracy of
0.005 mm can be obtained by honing
process
6. Honing is wet cutting process. 6
to 8 honing sticks are held
together and metal is removed by
rotating or reciprocating the
holder.
Honing tool is rotated at a speed
of 0.5 - 2.5 m/s and reciprocates
at a speed of 0.2 – 0.5 m/s.
7. Objectives are achieved by honing
1. Metal is removed
2. Roundness & straightness is obtained
3. Accurate dimension is obtained
4. Required surface finish is obtained.
•Application :
-Honing Of Automobile Cylinder
-Honing Is Also Used For Repair Work
8. • LAPPING
This process mainly done on the meting
surfaces. Abrasive compound or solid bonded
abrasive is used in it. More accuracy is obtained
as heat & pressure are less in lapping. Lapping
compound is made by mixing diamond, silicon
carbide, aluminum oxide in oil or water. There
are many types of lapping process.
9. • HAND LAPPING
In this method lapping compound is
spread on cast iron plate and work
piece is moved manually on it on a path
like English figure – 8.
10. • Machine lapping
In this method a rotating table is used in
place of the plate. Again the work piece
to be lapped is given rotary by a cage and
rotated on the surface of the table.
Rotating lap is used above & below the
work piece to produce parallel surfaces.
11. - Machine lapping process is carried out for gauge blocks, piston pin, ball
bearings and engine valves.
Application of lapping:-
12. • SUPER FINISHING
This process is one type of honing , in
which as compared to the honing less
pressure, high speed, huge amount of
lubricant – coolant of low viscosity and
more contact area between work &
abrasive face is kept. Less heat is
produced during super finishing and it is
generally done on external surfaces.
13. • POLISHING
Abbrasive material is bond
to a tool (disc, belt) or it is a media (paste)
freely between tool (textile disc, belt) and
part
NO improve in shape or accuracy!!
Just improves the surface quality
