High%20speed%20machining%20of%20Titanium%20alloy

1
High speed machining of Titanium alloy

• Under the guidance of-
• Prof. P.V. Rao
• and
• Dr. S. Ghosh

• Submitted by-
• Bijoy Bishai
• 2010MEP2985

2
Outline of Presentation

• Introduction
• Literature review
• Objective of project
• Work plan
• Experimental Setup
• Experimental Results Analysis
• Current status of work
• Conclusions and Future Scope of Work
• References

3
Introduction

• Titanium is broadly used in a number of fields,
  including aerospace, power generation,
  automotive, chemical and petrochemical, sporting
  goods, dental and medical industries.
• The large variety of applications is due to its
  desirable properties mainly the relative high
  strength combined with low density and enhanced
  corrosion resistance.

4
Contd.

• Alpha titanium alloys are especially formed by CP
  (Commercially Pure) titanium and alloys with
  a-stabiliser elements, which present only a phase
  at room temperature. These alloys are proper for
  very low temperature applications.
• Beta titanium alloys are obtained when a high
  amount of ß -stabiliser elements are added to
  titanium, which decreases the temperature of the
  allotropic transformation (a / ß transition) of
  titanium.
• a ß alloys include alloys with enough a and
  ß-stabilisers to expand the a ß field to room
  temperature. These alloys are used chiefly for
  high strength applications at elevated
  temperatures ranging in between 350C and 550C.
  The Ti-6Al-4V alloy is an example of a ß type
  alloy.

5
Landing Gear
Titanium Flanges
6
Piston Pins
Engine Valves
Idler Shaft
Cam Shaft
7
Literature review

• Titanium alloys are usually machined with
  uncoated straight grade cemented carbide (WC-Co)
  tool at higher cutting speeds in excess of 45
  m/min.
• At high speed conditions tend, it to generate
  high temperature close to the tool nose resulting
  in excessive stresses which results in severe
  plastic deformation and subsequent failure of the
  tool.
• At high temperature conditions titanium atoms
  diffuse into the carbide tool material and react
  chemically with carbon present in the tool to
  form an interlayer of titanium carbide (TiC)
  which bonds strongly to both the tool and the
  chip.

8
Contd.

• The lowest critical temperature at which adhesion
  (bonding) could occur is 740C at a normal
  contact pressure of 0.23 GPa.
• Temperature plays a major part in tool failure
  during machining, it is essential to minimize or
  even eliminate the temperature generated at the
  tool-work piece and tool-chip interfaces.

9
Improvement of the machining of Titanium Alloys

• Several investigations have shown that applying
  high-pressure coolant (HPC) technology not only
  increase production efficiency, by increasing the
  cutting speed but also improves chip removal
  mechanism, resulting in increased tool life while
  machining titanium alloys using mostly uncoated
  carbide tools.
• Shane Y. Hong et.al. (2001) reported that in
  cryogenic machining of titanium alloy with
  uncoated carbide tools, high cutting and thrust
  forces are generated compared to conventional
  cooling or dry machining processes. However they
  observed that the feed force got reduced mostly
  due to lower friction when liquid nitrogen is
  used as the cryogenic coolant.

10
Tool geometry modification for improving
machinability

• N.R. Dhar. et. al. (2002) reported that during
  machining of steel rods (AISI 1040 and E4340C
  steel) with carbide inserts having grooves along
  the cutting edges and hills on the tool rake
  face, cryogenic cooling reduces the average
  cutting temperature, because the above said
  geometry has helped the cryogenic jet to come
  closer to the chip tool interface thus
  effectively cooling the interface.

11
Contd.

• Dhananchezian and Pradeep Kumar (2011)
  investigated the effect of liquid nitrogen when
  it is applied to the rake surface and the main
  and auxiliary flank surfaces through holes made
  in the cutting tool insert during the turning of
  the Ti-6Al-4V alloy with modified cutting tool in
  the cryogenic cooling method. They have reported
  that by using the cryogenic cooling methods the
  cutting temperature was decreased by 61-66,
  cutting force decreased by 35-42, surface
  roughness reduced to a maximum of 35 over wet
  machining respectively.

12
Objective of project

• To execute the turning experiments without
  modified tool and study machining
  characteristics under dry and wet condition.
• To bring about appropriate modifications in
  existing tool inserts so that cutting forces may
  be reduced.
• To bring about improvement in machining
  characteristics of the titanium alloy by use of
  modified tool inserts.
• To experimentally evaluate the efficacy of the
  modified tool inserts while machining of titanium
  alloy under wet conditions.
• Finally optimize process parameters to be used to
  obtain maximum benefits while using the modified
  tool.

13
Work plan

• Cutting speed, feed rate and depth of cut are
  the input variables and cutting force and surface
  finish of the machined part is considered as an
  output performance characteristics.
• The specifications of the straight carbide K20
  grade insert is CNMA120408 K313.
• Effective rake angle of -6

S.No Factors Symbol. Level-1 Level-2 Level-3 Level-4
1 Cutting speed (m/min) V 60 80 100 120
2 Feed (mm/rev) f 0.04 0.08 0.12 0.16
3 Depth of cut (mm) d 0.4 0.8 1.2 1.6
14
Contd.

• As per the full factorial design, a total of 64
  experiments are needed to be carried out.
• All 64 experiments is repeated for machining of
  Ti-6Al-4V by using uncoated straight carbide
  inserts without modified tool under different
  environment (dry, wet etc.).
• All 64 experiments is repeated for machining of
  Ti-6Al-4V by using uncoated straight carbide
  inserts with modified tool under wet environment.

15
Experimental Setup

• The Leadwell T-6 lathe machine was used to
  conduct the experiments.
• Kistler multi- component Dynamometer 9129AA was
  used for measuring the three component of the
  resultant cutting force acting on the tool.
• The dynamometer is mounted on the tool holding
  fixture of the turret using a machine adapter
  type 9129AD.
• The dynamometer consists of four 3 component
  force sensors. The dynamometer can measure forces
  (in each of the three directions) in the
  range-10kN to10kN.

16
Contd.
Leadwell T6 CNC Lathe
17
Tool Geometry Modification
18
Contd.
19
Experimental Results

• Experiments with unmodified tool under dry
  condition were done. Force values and surface
  roughness values had observed.
• Experiments with unmodified tool under wet
  condition were done. Force values and surface
  roughness values had observed.
• Experiments with modified tool under wet
  condition were done. Force values and surface
  roughness values had observed.
• Force values and surface roughness values
  obtained with unmodified and modified cutting
  tool under wet environment is compared.

20
Experimental Results of turning with unmodified
cutting tool under dry environment

• plot of Fz with V, f and doc

• plot of Fx with V, f and doc

21
Contd.

• plot of Fy with V, f, doc

• plot of Ra with V, f and doc

22
Experimental Results of turning with unmodified
cutting tool under wet environment

• plot of Fz with V, f and doc

• plot of Fx with V, f and doc

23
Contd.

• plot of Fy with V, f, doc

• plot of Ra with V, f and doc

24
Experimental Results of turning with modified
cutting tool under wet environment

• plot of Fz with V, f and doc

• plot of Fx with V, f and doc

25
Contd.

• plot of Ra with V, f and doc

• plot of Fy with V, f, doc

26
Comparative Results of Fz of Wet Unmodified and
Wet modified

• With variation of V

• With variation of f

27
Contd.
With Variation of doc
28
Comparative Results of Ra of Wet Unmodified and
Wet modified

• With variation of V

• With variation of f

29
Contd.
With Variation of doc
30
Comparative Results of Fy of Wet Unmodified and
Wet modified

• With variation of V

• With variation of f

31
Contd.
With Variation of doc
32
Current status of work

• Objectives have been formulated.
• Cutting tool have been identified.
• Preliminary tool geometry modification has been
  done.
• Experiments on dry environment with unmodified
  cutting tool have been done.
• Experiments on wet environment with unmodified
  cutting tool have been done.
• Experiments on wet environment with modified
  cutting tool have been done.

33
Conclusions

• Turning was done under dry environment with
  unmodified tool. It was observed that forces
  value is higher compare to other engineering
  material like mild steel etc.
• Machining was done under wet environment with
  unmodified tool. It was observed that forces
  value come down as compare to the forces values
  under dry condition.
• Machining was done under wet environment with
  modified tool. It was observed that forces value
  came down as compare to the one that are obtained
  during machining with unmodified tool.
• Surface roughness value obtained by using the
  modified tool is slightly more than the one
  obtained for unmodified tool.

34
Future Scope of Work

• There is a lot can be done to further improve the
  machining of Ti-alloy from this approach.
• Surface roughness value of machined surface under
  wet Environment with modified cutting tool is
  slightly higher than that obtained in machining
  under wet condition with unmodified tool.
• Further modification can be done so that surface
  roughness value and forces can further reduce.
• Study can be done to optimize the process
  parameters.

35
Gantt Chart showing the Work Plan
36
References

• Lutjering, G., William, J.C., Gysler, A.,2003.
  Microsturcture and Mechanical properties of
  Titanium Alloys, Technical university
  Hamburg-Harburg,Hamburg, Germany.
• Jaffer,S.I.,Mativenga,P.T.,2009.Assesment of the
  Machinability of Ti-6AI-4v using the wear map
  approach.Int J Adv Manu Technol(2009)40687-696.
• Jawaid,A.,Che-Haron,C.H..,Abdullah,A 1999.Tool
  wear characteristics in turning of Titanium alloy
  Ti-6246.J.Mater.Process.Technol.92-93(1999)329-334
  
• Che-haron,C.H.,2001.Tool life and surface
  integrity in turning titanium alloy.J.Mater.Proces
  .Technol.118(2001)231-237
• Bryant, W.A.1998.Cutting tool for machining
  titanium and titanium alloys.US Patent
  5,718,541(17february 1998).
• Hartung, P.D., Karmer, B.M., 1982. Tools wear in
  titanium machining. Ann. CIRP 31 (1) (1982)
  75-80.
• Ezugwu, E.O., Bonney, J. Da Silva, R.B. Cakir,
  O.2007. Surface integrity of finished turned
  Ti-6Al-4V alloy with PCD tools using conventional
  and high pressure coolant supplies, International
  Journal of Machine Tools and Manufacture 47 (2)
  (2007) 247-254.

37
References

• Diniz, A.E., Microni, R. 2007 Influence of the
  direction and flow rate of cutting fluid on tool
  life in turning process of AISI 1045 steel,
  International Journal of Machine Tools and
  Manufacture 47 (2) (2007) 247-254.
• Ezugwu, E.O., Bonney, J. Da Silva, R.B., Bonny,
  J., Machado, A.R. 2005. Evalution of the
  performance of CBN tools when turning
  Ti-6Al-4Valoy with high pressure coolant
  supplies, International Journal of Machine Tools
  and Manufacture 45 (9) (2005) 1009-1014.
• Shane Y. Hong, Yucheng ding, Woo-cheol Jeong.
  2001. Friction and cutting forces in cryogenic
  machining of Ti-6Al-4V. International Journal of
  Machine Tools and Manufacture 41 (2001)
  2271-2285.
• Jawashir, I.S. 1998. A survey and future
  prediction for use to chip breaking in unmanned
  systems. International Journal of of Advance
  Manufacturing Technology. 3 (1998) 87-104.
• Dhar N.R., Paul S, Chattopadhyay A B. 2002. The
  influence of cryogenic cooling on tool wear,
  dimentional accuracy and surface finish in
  turning AISI 4140 and E4340C steels. Wear
  249(2002) 932-942.
• Dhananchezian, M., Pradeep kumar, M. 2011.
  Cryogenic turning of the Ti-6Al-4V alloy with
  modified cutting tool inserts. Cryogenics
  51(2011) 34-40.

38
THANK YOU