Aluminum-based MMC machining with diamond-coated cutting tools

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Aluminum-based MMC machining with diamond-coated
cutting tools

• S. Durante, G. Rutelli, F. Rabezzana
• October 1997
• Presented by Nathan Rasmussen

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Presentation Outline

• Heading                                           
                                              
  Title of Paper, Author (s), Date
• Introduce paper                                   
                                          
  Function of paper      Why important          
  References           
• Models, Design Application                        
                                 Relate to
  technical area in course         Parameters
  defined, design defined      Design
  principle                             
• Results                                           
                                               
      Experimental equipment discussed     Design
  principles applied                   
  Data/tables/design discussed            
  Correlation of results with models   
• Conclusions                                       
                                           
  Practical industrial use         Technical
  advancement         Industries most impacted 

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Function of Paper

• Investigation of an alternative solution for
  machining aluminum metal matrix composites (MMCs)
• Machining process produces SiC powder and hard
  particles from tool wear which create a highly
  abrasive environment.
• Tool life comparison of
• Standard Carbide Tooling
• Polycrystalline Diamond (PCD) Tooling
• Chemical-Vapor Deposition (CVD) diamond-coated
  Tooling

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Importance

• Aero, auto, and train industries are searching
  for lighter high-strength alloys
• MMCs fill those needs but have traditionally
  required more expensive tooling like PCD inserts
• Chemical-Vapor Deposition (CVD) diamond-coated
  inserts appear to be a promising alternative

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References

• DURALCAN Composites Maching Guidelines, 8/2/1991
• M.K. Aghajanian, C.A. Anderson, R.J. Wiener and
  B.R. Rossing. SAE Technical Paper, 950263,
  February 27-March2, 1995
• S. Durante, F. Rabezzana and G. Rutelli, in
  Eurodiamond 96, Torino, 1996, p. 135.
• I.E. Clark, IDR Ind. Diam. Rev., 54(3) (1994)
  562.
• S. Durante, in 26th AIM Congress Proceedings,
  Milano, 1996.
• M. Eastman and C. Lane, Cutting Tool Engineering,
  October (1993).

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Relationship to Course

• Tool life criteria flank wear
• Some of their data could have been fit to the
  Taylors tool life equation -- vTn C
• Coating technology insert parameters

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Design Parameters

• Benchmarks 3 different CVD diamond-coated
  inserts
• Two speeds three depths of cut
• Three test materials
• Tool life criterion - .4mm average flank wear

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Design Principles

• Tool Material
• Tool Geometry
• Coatings

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Experimental Equipment

• Turning - all inserts tested with turning
• All operations done on a SAG 101 Graziano Lathe
  equipped with a dynamometric device
• Machine Capacity P 60 kW and n 5000 rev/min
• Inserts installed on a CSBPR 20 20 K 12 Tool
  Holder
• Milling Machine tool not specified
• Did not test CVD diamond-coated inserts with this
  setup
• Drilling Machine tool not specified
• Did not test CVD diamond-coated inserts with this
  setup

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Applied Design Principles

• Coating technology for depositing thin layers of
  diamond (hot filament and DC plasma jet CVD
  processes)
• Applied a chamfer to CVD diamond coated tools to
  redistribute the force load on the edge
• Did not take the opportunity to fit data to the
  Taylors tool life model

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Benchmark Turning Test Results

• Standard carbide cutting tools with TiN coatings
  have relatively short lives
• PCD tools last 2.5 to 7 times longer depending on
  MMC composition

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Turning with a 10 mm CVD Diamond-Coated Insert
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Turning with a 15 mm CVD Diamond-Coated Insert

• Y axis in seconds? chipping was still a
  significant problem

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Turning with a 30 mm CVD Diamond-Coated Insert

• Changed the surface pretreatment
• Added a 15 degree x 0.1 mm chamfer

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Turning with a 30 mm CVD Diamond-Coated Insert

• Changed the surface pretreatment
• Added a 15 degree x 0.1 mm chamfer

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PCD vs PCD Coated Inserts

• 30 mm coated tool lasted roughly half that of a
  PCD tool
• CVD inserts are indexible so may be worth the
  cost
• If better organized then could have come up with
  some Taylor tool life constants for CVD inserts.

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Conclusions

• Thick CVD diamond coatings worked while thinner
  ones were prone to chipping
• The substrate surface preparation has a
  significant impact on adhesion of coating
• Course substrates are better than fine ones
• Diamond-coated tool life still cannot be compared
  to PCD tool life
• No real solid data or models for predicting the
  life of a CVD diamond-coated tool

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Practical Industrial Use

• Machining any nonferrous materials such as plain
  aluminum alloys or titanium
• Machining Aluminum based MMCs with Al2O3 and SiC

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Technology Advancement1

• CVD Diamond-Coated Inserts
• Price is around 50 - 70 for indexible quad
• Capable of high speed machining up to 6000 sfpm
• Recommend using high pressure coolant for
  interface integrity
• "Their commercial viability is proven. They can
  do the work and, in some applications, they are
  the only way to do the work."
• PCD Inserts
• Price is around 80 - 100 per insert for single
  point
• They can now be formed with complex geometry
• Still last longer than CVD diamond-coated inserts

1. Diamond-Coated Carbide Inserts-Ready, Set, Go!
   by Chris Koepfer, Senior Editor

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Industries Most Impacted

• PCD insert industry
• Aerospace
• Automotive
• Trains
• Racing
• Any other industry looking for a lighter
  high-strength material that can be machined

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Questions?