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Arc Welding and Hybrid Laser-Arc Welding

  • Ian Richardson
Part of the Springer Series in Materials Science book series (SSMATERIALS, volume 119)

Abstract

Laser-arc hybrid welding has developed into a viable industrial technology in recent years, and is attracting increasing commercial interest. The physics of the underlying interactions is quite complex. In order to explore the relationships involved, it is useful to consider important aspects of laser and arc welding separately. The physics of laser welding has already been examined in Chaps. 3 and 4. A generic description of welding arcs is therefore provided here, which forms a basis for interpretation of laser-arc interactions and the hybrid welding conditions discussed in the final section of this chapter.

Keywords

Weld Pool Welding Speed Hybrid Welding Weld Pool Surface Cathode Sheath 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Guile AE (1969) Arc Cathode and Anode Phenomena. International Institute of Welding (IIW) Document 212–170–69Google Scholar
  2. 2.
    Zijp JP (1990) Heat Transport During Gas Tungsten Arc Welding. PhD thesis, Delft University of Technology, The NetherlandsGoogle Scholar
  3. 3.
    Lancaster J (1984) The Physics of Welding. Pergamon PressGoogle Scholar
  4. 4.
    Ducharme R, Kapadia P, Dowden J, Thornton M, Richardson IM (1995) A Mathematical Model of the Arc in Electric Arc Welding, Including Shielding Gas Flow and Cathode Spot Location. J Phys D: Appl Phys 28(9): 1840–1850CrossRefADSGoogle Scholar
  5. 5.
    Kovitya P, Lowke JJ (1985) Two-dimensional Analysis of Free Burning Arcs in Argon. J Phys D: Appl Phys 18: 53–70CrossRefADSGoogle Scholar
  6. 6.
    Haddad GN, Farmer AJD (1984) Temperature Determinations in a Free-Burning Arc: I. Experimental Techniques and Results in Argon. J Phys D: Appl Phys 17: 1189–1196CrossRefADSGoogle Scholar
  7. 7.
    Olsen HN (1959) Thermal and Electrical Properties of an Argon Plasma. Phys Fluids 2(6): 614–623CrossRefADSGoogle Scholar
  8. 8.
    Greim HR (1964) Plasma Spectroscopy. McGraw-HillGoogle Scholar
  9. 9.
    Degout D, Catherinot A (1986) Spectroscopic Analysis of the Plasma Created by a Double-Flux Tungsten Inert-Gas (TIG) Arc Plasma Torch. J Phys D: Appl Phys 19(5): 811–823CrossRefADSGoogle Scholar
  10. 10.
    Thornton MF (1993) Spectroscopic Determination of Temperature Distributions for a TIG Arc. PhD thesis, Cranfield Institute of Technology, UKGoogle Scholar
  11. 11.
    Cram LE, Poladian L, Roumeliotis (1988) Departures from Equilibrium in a Free-Burning Argon Arc. J Phys D: Appl Phys 21: 418–425CrossRefADSGoogle Scholar
  12. 12.
    Gomées AM (1983) Criteria for Partial LTE in an Argon Thermal Discharge at Atmospheric Pressure; Validity of the Spectroscopically Measured Electronic Temperature. J Phys D: Appl Phys 16: 357–378CrossRefADSGoogle Scholar
  13. 13.
    Drellischak KS, Knopp CF and Cambel AB (1962) Partition Functions and Thermodynamic Properties of Argon Plasma. Gas Dynamics Laboratory, Nothwestern University, Illinois, USA. Report No A-3-62Google Scholar
  14. 14.
    Farmer AJD, Haddad GN (1988) Rayleigh-Scattering Measurements in a Free-Burning Argon Arc, J Phys D: Appl Phys 21(3): 426–431CrossRefADSGoogle Scholar
  15. 15.
    Farmer AJD, Haddad GN (1984) Local Thermodynamic-Equilibrium in Free-Burning Arcs in Argon. Applied Physics Letters 45(1): 24–25CrossRefADSGoogle Scholar
  16. 16.
    Bakshi V, Kearney RJ (1989) An Investigation of Local Thermodynamic Equilibrium in an Argon Plasma Jet at Atmospheric Pressure. J Quant Spect Rad Trans 41(5): 369–376CrossRefADSGoogle Scholar
  17. 17.
    Snyder SC, Lassahn GD, Reynolds LD (1993) Direct Evidence of Departures from Local Thermal Equilibrium in a Free-burning Arc-discharge Plasma. Phys Rev E 48 5: 4124–4127CrossRefADSGoogle Scholar
  18. 18.
    Kitamura T, Takeda K, Shibata K (1998) Deviation from Local Thermal Equilibrium State in Thermal Plasma. ISIJ International 38(11): 1165–1169CrossRefGoogle Scholar
  19. 19.
    Thornton MF (1993) Spectroscopic Determination of Temperature Distributions for a TIG Arc J Phys D: Appl Phys 26: 1432–1438CrossRefADSGoogle Scholar
  20. 20.
    Rat V, Aubreton J, Elchinger MF, Fauchais P, Murphy AB (2002) Diffusion in Two-temperature Thermal Plasmas 66: 056407Google Scholar
  21. 21.
    Murphy AB (1996) Modelling and Diagnostics of Plasma Chemical Processes in Mixed-Gas Arcs. Pure and Appl Chem 68(5): 1137–1142CrossRefGoogle Scholar
  22. 22.
    Murphy AB (1993) Diffusion in Equilibrium Mixtures of Ionized Gases. Phys Rev E 44(5): 3594–3603CrossRefADSGoogle Scholar
  23. 23.
    Murphy AB (1996) A Comparison of Treatments of Diffusion in Thermal Plasmas. J Phys D: Appl Phys 29(7): 1922–1932CrossRefADSGoogle Scholar
  24. 24.
    Murphy AB and Arundell CJ (1994) Transport Coefficients of Argon, Nitrogen,Oxygen, Argon-nitrogen, and Argon-oxygen Plasmas. Plasma Chem Plasma Process 14(4): 451–490CrossRefGoogle Scholar
  25. 25.
    Devoto RS (1966) Transport Properties of Ionized Monatomic Gases. Phys Fluids 9(6): 1230–1240CrossRefADSGoogle Scholar
  26. 26.
    Murphy AB (1996) The Influence of Demixing on the Properties of a Free Burning Arc. Appl Phys Lett 69(3): 323–330CrossRefADSGoogle Scholar
  27. 27.
    Murphy AB (1997) Demixing in Free-burning Arcs. Phys Rev E 55(6): 7473–7494CrossRefADSGoogle Scholar
  28. 28.
    Greses-Juan J (1999) Examination of Adaptive control Strategies for Hyper-baric Keyhole Plasma Arc Welding. MSc thesis, Cranfield University, UKGoogle Scholar
  29. 29.
    Aubreton A, Elchinger MF (2003) Transport Properties in Non-equilibriumArgon, Copper and Argon–copper Thermal Plasmas, J Phys D: Appl Phys 36(15): 1798–1805CrossRefADSGoogle Scholar
  30. 30.
    Rethfeld B, Wendelstorf J, Klein T, Simon G (1996) A Self-Consistent Model for the Cathode Fall Region of an Electric Arc. J Phys D: Appl Phys 29: 121–128CrossRefADSGoogle Scholar
  31. 31.
    Chen MM, Thorne RE, Wyner EF (1976) Resolution of Electron Emission Mechanisms in an Argon Arc with Hot Tungsten Cathode, J Appl Phys 47(12): 5214–5217CrossRefADSGoogle Scholar
  32. 32.
    Klein T, Paulini J, Simon G (1994) Time-resolved Description of Cathode Spot Development in Vacuum Arcs. J Phys D: Appl Phys 27: 1914–1921CrossRefADSGoogle Scholar
  33. 33.
    Morrow R, Lowke JJ (1993) A One-Dimensional Theory for the Electrode Sheaths of Electric-Arcs. J Phys D: Appl Phys 26(4): 634–642CrossRefADSGoogle Scholar
  34. 34.
    Spataru C, Teillet-Billy D, Gauyacq JP, Teste P, Chabrerie JP (1997) Ion-assisted Electron Emission from a Cathode in an Electric Arc, J Phys D: Appl Phys 30: 1135–1145CrossRefADSGoogle Scholar
  35. 35.
    Hsu KC, Pfender E (1983) Analysis of the Cathode region of a Free Burning High Intensity Argon Arc. J Appl Phys 54(7): 3818–3824CrossRefADSGoogle Scholar
  36. 36.
    Delalondre C, Simonin O (1990) Modeling of High-Intensity Arcs Including a Non-equilibrium Description of the Cathode Sheath. Journal De Physique 51(18): C5199–C5206Google Scholar
  37. 37.
    Wendelstorf J (2000) Ab Initio Modelling of Thermal Plasma Gas Discharges (Electric Arcs). PhD thesis, University of Braunschweig, GermanyGoogle Scholar
  38. 38.
    Murphy EL, Good RH (1956) Thermionic Emission, Field Emission and the Transition Region. Phys Rev 102(6): 1464–1473CrossRefADSGoogle Scholar
  39. 39.
    Coulombe S, Meunier JL (1997) A Comparison of Electron-emission Equations used in Arc-cathode Interaction Calculations. J Phys D: Appl Phys 20(30): 2905–2910CrossRefADSGoogle Scholar
  40. 40.
    Quigley MBC, Richards PH, Swift-Hook DT, Gick AEF (1973) Heat-Flow to the Workpiece from a TIG Welding Arc. J Phys D: Appl Phys 6(18): 2250–2258CrossRefADSGoogle Scholar
  41. 41.
    Ushio M, Tanaka M, Lowke JJ (2004) Anode Melting from Free-Burning Argon Arcs. IEEE Trans Plasma Sci 32(1): 108–117.CrossRefADSGoogle Scholar
  42. 42.
    Tanaka M, Ushio M, Wu CS (1999) One-dimensional Analysis of the Anode Boundary Layer in Free-burning Argon Arcs. J Phys D: Appl Phys 32: 605–611CrossRefADSGoogle Scholar
  43. 43.
    Lowke JJ, Morrow R, Haidar J (1997) A Simplified Unified Theory of Arcs and their Electrodes. J Phys D: Appl Phys 30: 2033–2042CrossRefADSGoogle Scholar
  44. 44.
    Hinnov E, Hirschberg JG (1962) Electron-ion Recombination in Dense Plasmas. Phys Rev 125(3): 795–801CrossRefADSGoogle Scholar
  45. 45.
    Jenista JJ, Heberlein VR (1997) Numerical Model of the Anode Region of High Current Electric Arcs. IEEE Trans Plasma Sci 25(5): 883–890CrossRefADSGoogle Scholar
  46. 46.
    Zhu P, Lowke J J, Morrow R, Haider J (1995) Prediction of Anode Temperatures of Free Burning Arcs. J Phys D: Appl Phys 28: 1369–1376CrossRefADSGoogle Scholar
  47. 47.
    Sanders NA, Pfender E (1984) Measurement of Anode Falls and Anode Heat Transfer in Atmospheric Pressure High Intensity Arcs. J Appl Phys 55(3): 714–722CrossRefADSGoogle Scholar
  48. 48.
    Yang G, Heberlein J (2007) Anode Attachment Modes and their Formation in a High Intensity Argon Arc. Plasma Sources Sci Technol 16: 529–542CrossRefADSGoogle Scholar
  49. 49.
    Kim W-H, Na S-J (1998) Heat and Fluid Flow in Pulsed Current GTA Weld Pool. Int J Heat and Mass Trans 41: 3213–3227CrossRefGoogle Scholar
  50. 50.
    Zhang W, Kim C-H, DebRoy T (2004) Heat and Fluid Flow in Complex Joints During Gas Metal Arc Welding Part I: Numerical Model of Fillet Welding. J Appl Phys 95(9): 5210–5219CrossRefADSGoogle Scholar
  51. 51.
    Wu CS, Yan F (2004) Numerical Simulation of Transient Development and Diminution of Weld Pool in Gas Tungsten Arc Welding. Modelling Simul Mater Sci Eng 12: 13–20CrossRefADSGoogle Scholar
  52. 52.
    Mishra S, DebRoy T (2005) A Heat-transfer and Fluid-flow Based Model to Obtain a Specific Weld Geometry using Various Combinations of Welding Variables. J Appl Phys 98: 044902CrossRefADSGoogle Scholar
  53. 53.
    Chakraborty N, Chakraborty S, Dutta P (2004) Three-dimensional Modeling of Turbulent Weld Pool Convection in GTAW Processes. Numerical Heat Transfer A 45: 391–413CrossRefADSGoogle Scholar
  54. 54.
    Jaidi J, Dutta P (2004) Three-dimensional Turbulent Weld Pool Convection in Gas Metal Arc Welding Process. Sci Technol Weld Join 9(5): 407–414CrossRefGoogle Scholar
  55. 55.
    Hu J, Tsai HL (2007) Heat and Mass Transfer in Gas Metal Arc Welding. Part I: The Arc. Int J Heat & Mass Trans 50: 808–820CrossRefGoogle Scholar
  56. 56.
    Hu J, Tsai HL (2007) Heat and Mass Transfer in Gas Metal Arc Welding. Part II: The Metal. Int J Heat & Mass Trans 50: 833–846MATHCrossRefGoogle Scholar
  57. 57.
    Richardson IM, Norrish J, Hermans HJM (2006) The Mechanism and Significance of Drop Spray Transfer in GMAW, International Institute of Welding (IIW) Document XII-1893-06Google Scholar
  58. 58.
    Choi BK, Ko SH, Kim YS (1998) Dynamic Simulation of Metal Transfer in GMAW – Part 1: Globular and Spray Transfer Modes. Weld J 77: 38s–44sADSGoogle Scholar
  59. 59.
    Fan HG, Kovacevic R (2004) A Unified Model of Transport Phenomena in Gas Metal Arc Welding Including Electrode, Arc Plasma and Molten Pool. J Phys D: Appl Phys 37: 2531–2544CrossRefADSGoogle Scholar
  60. 60.
    Hu J, Tsai HL (2006) Effects of Current on Droplet Generation and Arc Plasma in Gas Metal Arc Welding J: Appl Phys 100: 053304CrossRefGoogle Scholar
  61. 61.
    Haidar J, Farmer AJD (1993) A Method for the Measurement of the Cathode Surface Temperature for a High-current Free-burning Arc. Rev Sci Instrum 64: 542–7CrossRefADSGoogle Scholar
  62. 62.
    Goodarzi M, Choo R, Toguri JM (1997) The Effect of the Cathode Tip Angle on the Gas Tungsten Arc Welding Arc and Weld Pool: I. Mathematical Model of the Arc. J Phys D: Appl Phys 30: 2744–2756CrossRefADSGoogle Scholar
  63. 63.
    Goodarzi M, Choo R, Takasu T, Toguri JM (1998) The Effect of the Cathode Tip Angle on the Gas Tungsten Arc Welding Arc and Weld Pool:II. The Mathematical Model for the Weld Pool. J Phys D: Appl Phys 31: 569–583CrossRefADSGoogle Scholar
  64. 64.
    Tanaka M, Ushio M, Lowke JJ (2004) Numerical Study of Gas Tungsten Arc Plasma with Anode Melting. Vacuum 73: 381–389CrossRefGoogle Scholar
  65. 65.
    Tanaka M, Ushio M, Lowke JJ (2004) Numerical Analysis for Weld Formation Using a Free-burning Helium Arc at Atmospheric Pressure. JSME Int J Series B 48(3): 397–404CrossRefADSGoogle Scholar
  66. 66.
    Lowke JJ, Tanaka M, Ushio M (2004) Mechanisms Giving Increased Weld Depth Due to a Flux. J Phys D: Appl Phys 38: 3438–3445CrossRefADSGoogle Scholar
  67. 67.
    Lowke JJ, Tanaka M (2007) Predictions of Weld Pool Profiles using Plasma Physics. J Phys D: Appl Phys 40: R1–R23CrossRefGoogle Scholar
  68. 68.
    Tanaka M, Tashiro S, Lowke JJ (2007) Predictions of Weld Formation using Gas Tungsten Arcs for Various Arc Lengths from Unified Arc-electrode Model. Sci Technol Weld Join 12(1): 2–9CrossRefGoogle Scholar
  69. 69.
    Lago F, Gonzalez JJ, Freton P, Gleizes A (2004) A Numerical Modelling of an Electric Arc and its Interaction with the Anode: Part I. The Two-dimensional Model. J Phys D: Appl Phys 37: 883–897CrossRefADSGoogle Scholar
  70. 70.
    Gonzalez JJ, Lago F, Freton P, Masquèere M, Franceries X (2005) Numerical Modelling of an Electric Arc and its Interaction with the Anode: Part II. The Three-dimensional Model -Influence of External Forces on the Arc Column. J Phys D: Appl Phys 38: 306–318CrossRefADSGoogle Scholar
  71. 71.
    Tanaka M, Yamamoto K, Tashiro S, Nakata K, Ushio M, Yamazaki K, Yamamoto E, Suzuki K, Murphy AB, Lowke JJ (2007) Metal Vapour Behaviour in Thermal Plasma of Gas Tungsten Arcs During Welding. International Institute of Welding (IIW) Document 212-1107-07Google Scholar
  72. 72.
    Quinn TP, Szanto M, Gilad I, Shai I (2205) Coupled Arc and Droplet Model of GMAW. Sci Technol Weld Join 10(1): 113–119CrossRefGoogle Scholar
  73. 73.
    Steen WM, Eboo M (1979) Arc Augmented Laser-Welding. Metal Construction 11(7): 332–335Google Scholar
  74. 74.
    Steen WM, Eboo M, Clarke J (1978) Arc Augmented Laser Welding. Proc 4th Int Conf Advances in Welding Processes, Harrogate, UK, 9–11 May. Paper 17: 257–265Google Scholar
  75. 75.
    Deron C, Rivièere P, Perrin M-Y, Soufiani A (2006) Coupled Radiation, Conduction, and Joule Heating in Argon Thermal Plasmas. J Thermophys & Heat Trans 20(2): 211–219CrossRefGoogle Scholar
  76. 76.
    Hughes TP (1975) Plasmas and Laser Light, Adam HilgerGoogle Scholar
  77. 77.
    Paulini J, Simon G (1993) A Theoretical Lower Limit for Laser Power in Laser-enhanced Arc Welding. J Phys D: Appl Phys 26: 1523–1527CrossRefADSGoogle Scholar
  78. 78.
    Seyffarth P, Krivtsun IV (2002) Laser-Arc Processes and their Applications in Welding and Material Treatment. Welding and Allied Processes Volume 1. Taylor & FrancisGoogle Scholar
  79. 79.
    Wang T-S, Rhodes R (2003) Thermophysics Characterization of Multiply Ionized Air Plasma Absorption of Laser Radiation. J Thermophys & Heat Trans 17(2): 217–224CrossRefGoogle Scholar
  80. 80.
    Stallcop JR, Billman KW (1974) Analytical Formulae for the Inverse Bremsstrahlung Absorption Coefficient. Plasma Physics 16: 1187–1189CrossRefADSGoogle Scholar
  81. 81.
    Devoto RS (1973) Transport Coefficients of Ionised Argon. Phys Fluids 16(5): 616–623CrossRefADSGoogle Scholar
  82. 82.
    Mathuthu M, Raseleka RM, Forbes A, West N (2006) Radial Variation of Refractive Index, Plasma Frequency and Phase Velocity in Laser Induced Air Plasma. IEEE Trans Plasma Sci 34(6): 2554–2560CrossRefADSGoogle Scholar
  83. 83.
    Howlader MK, Yang Y, Roth JR (2005) Time-Resolved Measurements of Electron Number Density and Collision Frequency for a Fluorescent Lamp Plasma Using Microwave Diagnostics. IEEE Trans Plasma Sci 33(3): 1093–1099CrossRefADSGoogle Scholar
  84. 84.
    Lacroix D, Jeandel G, Boudot C (1998) Solution of the Radiative Transfer Equation in an Absorbing and Scattering Nd:YAG Laser-induced Plume. J Appl Phys 84(5): 2443–2449CrossRefADSGoogle Scholar
  85. 85.
    Kokhanovsky AA (1999) Optics of Light Scattering Media. John Wiley & Sons and Praxis PublishingGoogle Scholar
  86. 86.
    Greses J (2003) Plasma/Plume Effects in CO2 and Nd:YAG Laser Welding. PhD thesis, Cambridge University, UKGoogle Scholar
  87. 87.
    Greses J, Hilton PA, Barlow CY, Steen WM (2002) Plume Attenuation under High Power Nd:YAG Laser Welding. J Laser Appl 16(1): 9–15CrossRefGoogle Scholar
  88. 88.
    Zimmer AT, Biswas P (2001) Characterization of the Aerosols Resulting from Arc Welding Processes. J Aerosol Science 32: 993–1008CrossRefGoogle Scholar
  89. 89.
    Hewett P (1995) The Particle Size Distribution, Density, and Specific Surface Area of Welding Fumes from SMAW and GMAW Mild and Stainless Steel Consumables. American Industrial Hygiene Association, Journal, 56: 128–135Google Scholar
  90. 90.
    Thomas ME (2006) Optical Propagation in Linear Media. Oxford University PressGoogle Scholar
  91. 91.
    Hansen F, Duley WW (1994) Attenuation of Laser Radiation by Particles During Laser Materials Processing. J Laser Appl 6(3): 137–143Google Scholar
  92. 92.
    Tu J, Miyamoto I, Inoue T (2002) Characterizing Keyhole Plasma Light Emission and Plasma Plume Scattering for Monitoring 20kW class CO2 Laser Welding Processes. J Laser Appl 14(3): 146–153CrossRefGoogle Scholar
  93. 93.
    Bagger C, Olsen F (2005) Review of Laser Hybrid Welding. J Laser Appl 17(1): 2–14CrossRefGoogle Scholar
  94. 94.
    Chen Y, Li L, Fang J, Feng X, Wu L (2003) Temperature Field Simulation of Laser-TIG Hybrid Welding. China Welding 12(1): 62–66Google Scholar
  95. 95.
    Chen Y, Li, L, Fang J, Feng X (2003) Numerical Analysis of Energy Effect in Laser-TIG Hybrid Welding. J Mater Sci Technol 19 Suppl 1: 23–26CrossRefGoogle Scholar
  96. 96.
    Hu B (2002) Nd:YAG Laser-assisted Arc Welding. PhD thesis Delft University of Technology, The NetherlandsGoogle Scholar
  97. 97.
    Reutzel EW, Kelly SM, Martukanitz RP, Bugarewicz MM and Michaleris P (2005) Laser-GMA [MIG/MAG] Hybrid Welding: Process Monitoring and Thermal Modelling. In: David SA, DebRoy T, Lippold JC, Smartt HB, Vitek JM (eds) Proc 7th Int Conf Trends in Welding Research, Pine Mountain, GA, USA, 16–20 May 2005. Publ: Materials Park, OH 44073-0002, USA; ASM International; 2006, pp 143–148Google Scholar
  98. 98.
    Goldak J, Chakravarti A, Bibby M (1984) A New Finite Element Model for Welding Heat Sources. Met Trans B 15B: 299–305CrossRefGoogle Scholar
  99. 99.
    Zaikin AE, Katulin VA, Levin AV, Petrov AL (1991) Hydrodynamic Processes in a Melt Bath under Laser-arc Interaction Conditions. Sov J Quantum Electron. 21(6): 635–639CrossRefADSGoogle Scholar
  100. 100.
    Gratzke U, Kapadia PD, Dowden J (1991) Heat-Conduction in High-Speed Laser-Welding. J Phys D: Appl Phys 24(12): 2125–2134CrossRefADSGoogle Scholar
  101. 101.
    Cline HE, Anthony TR (1977) Heat Treating and Melting Material with a Scanning Laser or Electron-Beam. J Appl Phys 8(9): 3895–3900CrossRefADSGoogle Scholar
  102. 102.
    Hu B, den Ouden G (2005) Synergic Effects of Hybrid Laser/Arc Welding. Sci Technol Weld Join 10(4): 427–431CrossRefGoogle Scholar
  103. 103.
    Dowden J, Kapadia PD (1998) The use of a High Power Laser to Provide an Electrical Path of Low Resistance. J Laser Appl 10(5): 219–223CrossRefGoogle Scholar
  104. 104.
    Startsev VN, Martynenko DP, Leonov AF (2000) Investigation of Characteristics of an Arc Column in Laser Arc Welding using Numerical Simulation. High Temp 38(1): 24–29CrossRefGoogle Scholar

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© Canopus Academic Publishing Limited 2009

Authors and Affiliations

  • Ian Richardson
    • 1
  1. 1.Department of Materials Science and EngineeringDelft University of TechnologyCD DelftThe Netherlands

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