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Fail Safe Drilling of CFRP/Titanium and /Aluminium Stack with H8 Quality for Aerospace Applications
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 17, 2013 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Ever since the advent of fiber reinforced polymer materials in the field of Aerospace, Metal-FRP stacks started to gain importance due to their superior fatigue performance, phenomenal low weight and good specific strength. However the machining, specially drilling these multi stack materials has always proved to be a challenge for the field of manufacturing and assembly. Drilling holes in only metal with a drill (metal drill), the material removal is through a process of clear shearing since the tool is much harder and sharper than the base material. The tools hence wears at a much slower and gradual rate, also the malleable properties of the machined metal compensate to the reduced cutting capability of the worn out drill. These properties of the machined metal act like a ‘FAIL SAFE’ mechanism during the machining process assuring a trouble free fail safe environment during the drilling process. However, drilling FRP composites is altogether a different story. The very properties that make the FRP composite superior make it a challenge for machining. The mechanism of machining viewed here is more or less fracturing and breakage of the fibers present in the system. This breakage of fiber also induces fractures in the tool resulting in accelerated tool wear. These characteristics render the process unreliable. Also the temperature during the machining of composites is higher than while machining a metal due to the lower thermal conductive properties of the composite. When two such extremely different elements are brought together in the form of a FRP-Metal stack, various challenges are faced to achieve required hole size, quality, tool life and most of all a FAIL SAFE Process.
This article elaborates about methods to achieve a FAIL SAFE process during the drilling of CFRP/Titanium and Aluminum stacks just by adding and optimizing certain geometric features to the drill. The article also goes through simplified theoretic models which show how CFRP/Titanium stacks should be machined “Fail Safe”, inside the required Cpk tolerance, without scratches and burn marks even when the drill is during its last stages its life. The concept of Micro Reamer Technology (patented by MAPAL) is discussed and the application of this technology to achieve the required hole quality, burr and other important parameters is elaborated. The only apparent indicator for the end of tool life would be a linear increase in the burr height.
CitationMueller-Hummel, P., Sripathy, P., and Atarsia, A., "Fail Safe Drilling of CFRP/Titanium and /Aluminium Stack with H8 Quality for Aerospace Applications," SAE Technical Paper 2013-01-2223, 2013, https://doi.org/10.4271/2013-01-2223.
Data Sets - Support Documents
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|Unnamed Dataset 2|
- DORNFELD , D. ; AVILA , M. ; ARDNER , J. ; REICHWEISER , C. ; VIJAYARAGHAVAN , A. Strategies for Burr Minimization and leanability in Aerospace and Automotive Manufacturing Consortium on Deburring and Edge Finishing, eScholarship Repository University of California Berkeley http://repositories.cdlib.org/lma/codef/avila 06 1 2006
- MIN , S. ; DORNFELD , D. ; KIM , J. ; and SHYU , B. Finite Element Modeling of Burr Formation in Metal Cutting Proc. 4th CIRP Int'l Workshop on Modelling of Machining Operations Delft August 2001
- MÜLLER-HUMMEL , P. ; RICHTER , J. ; MÖLLER , B. Neue Werkstoffe fordern neue Allianzen Werkstatt und Betrieb Carl Hanser Verlag München WB 10 2008
- VIJAYARAGHAVAN , A. ; DORNFELD , D. Challenges in Modelling Machining of Multilayer Materials Proc. Of 8th CIRP Int'l Workshop on Modelling of Machining Operations” 17 24 2005
- MÜLLER-HUMMEL , P. ; LAHRES , M. Infrared Temperature Measurement on Diamond-Coated Tools during Machining Bachmann , P. K. ; Bruckley-Golder , I.M. ; Glass , I. T. ; Kamo , M. Proc. of 4th. European Conference on Diamond, Diamond-like and Related Materials Albufeira, Portugal Elsevier Sequoia S.A., Lausanne 765 1993
- MÜLLER-HUMMEL , P. ; LAHRES , M. A New Instrument to optimize cutting Processes: In Situ Temperature Measurement on Diamond - coated Tools Innovations in Material Research World Scientific Publishing 1996 1 1 1 9 1996
- Brinksmeier , E. ; Janssen , R. 2002 Drilling of Multi-Layer Composite Materials consisting of Carbon Fiber Reinforced Plastics (CFRP), Titanium and Aluminum Alloys CIRP Annals - Manufacturing Technology 51 1 87 90
- Kim Dave ; Kwon Patrick Evaluation of Advanced Cutting Tool Materials for Drilling Composite/Metal Stacks
- Dornfeld , D.A. ; Kim , J.S. ; Dechow , H. ; Hewson , J. ; Chen , L.J. 1999 Drilling Burr Formation in Titanium Alloy, Ti-6AI-4V CIRP Annals - Manufacturing Technology 48 1 73 76
- Kress Dieter Dr. , Müller-Hummel Peter Dr. Publised Patent; WO 2012/104066 A1 1 February 2012
- Wong F.R. , Sharif S. , Kamdani K. , Rahim E.A. The Effect of Drill Point Geometry and Drilling Technique on Tool Life when Drilling Titanium Alloy Ti-6Al-4V
- GHIDOSSI , P. ; MANSORI , M. ; PIERRON , F. 2006 Influence of specimen preparation by machining on the failure of polymer matrix off-axis tensile coupons Composites Science and Technology 66 11-12 1857 1872
- Lantrip J. New tools needed Cutting Tool Engineering 60 8 2008
- Kim , D. ; Ramulu , M. 2004 Drilling process optimization for graphite/bismaleimide-titanium alloy stacks Composite Structures 63 1 101 114
- Ramulu M ; Branson T ; Kim D A Study of drilling composite and titanium stacks
- Park , Kyung-Hee ; Beal , Aaron ; Kim , Dave ; Kwon , Patrick ; Lantrip , Jeff 2011 Tool wear in drilling of composite/titanium stacks using carbide and polycrystalline diamond tools Wear 271 11-12 2826 2835
- Rawat , Sanjay ; Attia , Helmi 2009 Wear mechanisms and tool life management of WC-Co drills during dry high speed drilling of woven carbon fibre composites Wear 267 5-8 1022 1030
- Sharif , S. ; Rahim , E.A. 2007 Performance of coated- and uncoated-carbide tools when drilling titanium alloy-Ti-6Al4V Journal of Materials Processing Technology 185 1-3 72 76
- Zitoune , Redouane ; Krishnaraj , Vijayan ; Sofiane Almabouacif , Belkacem ; Collombet , Francis ; Sima , Michal ; Jolin , Alain 2012 Influence of machining parameters and new nano-coated tool on drilling performance of CFRP/Aluminium sandwich Composites Part B: Engineering 43 3 1480 1488
- Zhang P.F. ; Churi N.J. ; Pei Z.J. ; Treadwell C. Mechanical drilling processes for titanium alloys: A literature review