The document discusses cryogenic machining, which uses liquid nitrogen as a coolant instead of conventional cutting fluids. It provides background on the history and development of cryogenic machining. Key benefits identified include increased tool life, higher material removal rates, improved surface finish, and reduced manufacturing costs. The document outlines the cryogenic machining process and analyzes factors like tool wear, cutting forces, surface roughness, and economic impacts. Results showed that cryogenic machining yielded the best tool life and lower forces compared to other methods.

1. CRYOGENIC MACHINING

2. LITERATURE REVIEW
Effectivene
ss of
cryogenic
machining
with
modified
tool holder
Mirghani I

3. INTRODUCTION
 Conventional cutting fluid serves both as a coolant and
lubricant. In cryogenic machining, liquid nitrogen (LN2) is
recognized as an effective coolant due to its low temperature.
 Because LN2 has different properties than the conventional
cutting fluid, the method of applying it to the cutting process
must be adjusted to gain the maximum benefit from LN2.
 Cryogenic machining, with liquid nitrogen as the coolant, has
been shown to be an effective method to significantly improve
the surface integrity of manufactured components in terms of
surface and surface hardness, microstructure modification,
phase transformation, residual stress, fatigue life etc.
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4. HISTORY OF CRYOGENIC
MACHINING
Cryogenic machining was first investigated around 1953 by
Bartley who used Liquid carbon dioxide as the coolant
(Chattopadhyay et al 1985). Hollis (1961) has studied the
effect of cryogenic cooling on the wear process of carbide
tipped tools during the machining of titanium. . They were
sprayed in the general cutting area or were applied to the work
piece before cutting in a prechill. This method however
consumed excessive amounts of cryogenic fluid and had no
lubrication effect. Additionally this reflects high costs and
present high complexity in delivering of cryo fluid to the
cutting zone
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5. TODAY’S SCENARIO OF CRYOGENIC
HARDENING
 Today the process of liquefaction and storage system
becomes more affordable.
There is a need to develop and rise the cryogenic machining
on an industrial level.Due to price availability, temperature, etc.
related to machining process
Characteristics and requirements, in this work as a
cryogenic fluid liquid nitrogen (LN) is going to be used.
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6. LIQUID NITROGEN PRODUCTION.
 Liquefaction of air is done.
 Compressor or generator compresses ,expanded and cooled
the air.
 Nitrogen boils at different temperature than oxygen the
nitrogen can be distilled out of liquid air recompressed and
then again re-liquefied.
 liquid nitrogen is removed from the distillation chamber , it
is stored either in a pressurized tank or a well insulated
Dewar Flask.
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7. CRYOGENIC MACHINING
• Cryogenic machining presents a method of cooling the cutting
tool and/or part during the machining process.
• More specifically, it relates to delivering of cryogenic (instead
of an oil-based CLF) to the local cutting region of the cutting
tool, which is exposed to the highest temperature during the
machining process, or to the part in order to change the
material characteristics and improve machining performance.
• The cryogenic coolant used in this work is nitrogen fluid.
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8. 11
FIG 1

9. 12
FIG 2 NOZZLE

10. BENEFITS OF CRYOGENIC MACHINING
• sustainable machining methods (cleaner, safer, environment
friendly, more health acceptable, etc.) to eliminate numerous
costs associated with conventional cutting fluids and clean-
up operations,
• increase of material removal rate without increases in
worn tool and tool change over costs
• increase of productivity, - increasing cutting speeds
without increases in worn tool and tool change over costs,
• increasing of tool life due to lower abrasion and chemical
wear.
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11. • machining of hard parts and hard to machine alloys,
which in the past, could have been produced only via
expensive grinding operations,
• surface roughness of machined work piece
improvement,
• produced parts quality improvement by
preventing mechanical and chemical degradation
of machined surface,
• potentially lower investment costs due to reduction in
number of machine tools required,
• improvement of manufacturing flexibility due to reduced
production times and high output,etc.
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12. DUE
TO
• Lower cutting temperatures in cutting zone,
• Improvement of chip breakability,
• Decreased BUE formation probability,
• Decreased of burr appearance probability,
• Inert environment assurance,
• No oil-based emulsion used,
• No additional processes needed,
• liquid nitrogen specifications,
• changes in material characteristics at lower
temperatures etc.
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13. USE OF CRYOGENIC MACHINING.
 Steel and Iron harder than 45 HRC.
 Sinter-hardened or heat-treated powdered metals.
 Hard metal-matrix composites.
 Cobalt Chromium and other dfficult materials for medical
implants, especially where it is desirable to avoid the possible
contamination effects of metal cutting fluids.
 Polymers and plastics that machine better when frozen,
especially those intended for medical use.
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14. ADVANTAGE
 Eco friendly
 High production rate are possible through higher material
removal rate.
 Tool life increases.
 Better surface finish
 Reduce machining time.
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15. TOOL-WEAR
• the commonly-known wear mechanisms are abrasive
wear, adhesive wear, diffusion wear, micro chipping,
fatigue, delamination wear.
• But only two wear play important role i.e abrasion
wear and build up edge wear.
• when the cutting speed is 50 m/min and feed rate is
0.125 mm/rev. Observing from the tool-wear images,
the abrasive flank wear is found in the nose areas for
all the three machining conditions.
• From fig it is clear that flank and nose wear is very
smaller.
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16. FORCE
S
• Two force components are presented in this paper,
including cutting force parallel to the direction of cutting
speed and thrust force perpendicular to the cutting
speed direction. Three sets of the cutting and thrust
forces were measured when the cutting speed was 50
m/min and the feed rate were 0.05, 0.125 and 0.2
mm/rev under the flood-cooled, MQL and cryogenic
condition.
• The cutting force from cryogenic machining
decreased by 6.3, 20.7 and 4.5%, respectively,
were
but for
understanding we take reading at 0.2 mm/rev feed rate.
Dry cutting Flank cooling Rake cooling Both rake and flank
Measured 865 447 335 208
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17. SURFACE ROUGHNESS
• the distributions of surface roughness at three
different feed rates of 0.05, 0.125 and 0.2
mm/rev and the cutting speed of 50 m/min.
• The surface roughness increased with the
increasing feet rates in all the three cooling
conditions.
• The geometric expression shown by equation
Ra= f²/(32R)
• For low feed rates, the surface roughness
measured on the sample from cryogenic
machining is higher than that of flood cooled and
MQL machining.
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18. ECONOMY
• Table 1. Production Rate and Production Cost Analysis In
Machining AISI304 Stainless Steel. Work piece
Specification: 304 stainless steel bar; diameter, 50.8 mm;
cutting length, 508 mm; cutting depth, 1.6 mm; Total volume
removal: 1.3!10–4 m3 ; Cutting condition: feed, 0.3 mm;
depth of cut, 1.6 mm; speed, as indicated.
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19. RESULT
• cryogenic machining approach yields the best tool life
compared with any machining method from current
known sources.
• cryogenic machining there is reductions of feed force,
cutting force effective coefficient of friction between the
chip and the tool face.
• using cryogenic conditions and gaining higher
performances, lower environmental and health
influences, increased safety, etc
• Nose wear of the insert was improved in cryogenic
machining due to reduced material adhesion.
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20. REFERENCE
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21. Thank you
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