Comparison of Ground and Laser Machined Polycrystalline Diamond (PCD) Tools in Cutting Carbon Fiber Reinforced Plastics (CFRP) for Aircraft Structures

The extended use of carbon reinforced plastics (CFRP ), especially in aircraft industries, requires effi cient machining solutions due to superior mechanical properties with a lower weig ht compared to metals. This material is highly abra sive, requiring very hard cutting materials and additionally only a sharp cut ting edge provides a sufficient surface quality on the workpiece. Ultrashort laser pulses and the focusability of high brilliance lase r systems enable diamond processing without relevant graphitization or other material deteriorating effects for polycrystalline diamond (PCD). This study focuses on a comparison of conventional and laser machined PCD cutting tool inserts and a characteriza tion of their machining characteristics. Conventiona l processing of the PCD tools is done using grinding processes on five axis machining centers. Laser manufacturing is done usi ng a five axis CNC machine with additional three axes for beam delivery. Compar able values in terms of surface roughness on flank and rake face as well as edge curvature radii are achieved. The comparison o f machining characteristics is done machining CFRP i n a continuous turning process with a single fiber orientation at cutting velocities of 200 m/min. Machining forces and the c utting edge radii are measured to evaluate tool wear. The resulting work piece qua lity is analyzed by measuring surface roughness and integrity using tactile surface roughness measurement (Taylor Hobson PGI 1240) and scanning electron microscopy (SEM).

[1]  K. Wegener,et al.  A study on laser touch dressing of electroplated diamond wheels using pulsed picosecond laser sources , 2011 .

[2]  H. Hocheng,et al.  The effect of chisel length and associated pilot hole on delamination when drilling composite materials , 2003 .

[3]  J. Paulo Davim,et al.  Damage and dimensional precision on milling carbon fiber-reinforced plastics using design experiments , 2005 .

[4]  Roberto Teti,et al.  Machining of Composite Materials , 2002 .

[5]  Jamal Y. Sheikh-Ahmad.  Machining of polymer composites , 2009 .

[6]  C. Tsaob,et al.  The path towards delamination-free drilling of composite materials , 2005 .

[7]  M. Henry,et al.  High Speed Processing Applications of High Average Power Diode Pumped Solid State Lasers , 2005 .

[8]  Konrad Wegener,et al.  Influence of cutting edge radius on cutting forces in machining titanium , 2010 .

[9]  A. Goeke,et al.  Analysis of laser ablation of CFRP by ultra-short laser pulses with short wavelength , 2011 .

[10]  Hong Shen,et al.  Fabrication and application of high quality diamond-coated tools , 2002 .

[11]  H. Hochengb,et al.  Effect of tool wear on delamination in drilling composite materials , 2007 .

[12]  J. Ferreira,et al.  Machining optimisation in carbon fibre reinforced composite materials , 1999 .

[13]  M. Henry,et al.  Laser processing of polycrystalline diamond, tungsten carbide, and a related composite material , 2006 .

[14]  David K. Aspinwall,et al.  Drill geometry and operating effects when cutting small diameter holes in CFRP , 2009 .

[15]  Oliver Meier,et al.  Investigations on the thermal effect caused by laser cutting with respect to static strength of CFRP , 2008 .

[16]  Y. K. Chou,et al.  Characterizations of nano-crystalline diamond coating cutting tools , 2007 .

[17]  Michael D. Gilchrist,et al.  The performance of coated tungsten carbide drills when machining carbon fibre-reinforced epoxy composite materials , 2002 .

[18]  Eckhard Beyer,et al.  Laser Cutting of Carbon Fiber Reinforced Polymers using Highly Brilliant Laser Beam Sources , 2011 .

[19]  Pal Molian,et al.  Micro- and Sub-Micromachining of Type IIa Single Crystal Diamond Using a Ti:Sapphire Femtosecond Laser , 2002 .

[20]  Ekkard Brinksmeier,et al.  Macro and micro process modeling of the cutting of carbon fiber reinforced plastics using FEM , 2011 .

[21]  Hatim Haloui,et al.  Laser ablation of CFRP using picosecond laser pulses at different wavelengths from UV to IR , 2011 .

[22]  Ekkard Brinksmeier,et al.  Drilling of composites and resulting surface integrity , 2011 .