Quality assessment in laser welding: a critical review

  • John Stavridis
  • Alexios Papacharalampopoulos
  • Panagiotis StavropoulosEmail author
Open Access
Original Article


Quality assessment methods and techniques for laser welding have been developed both in- and post-process. This paper summarizes and presents relevant studies being classified according to the technology implemented (vision, camera, acoustic emissions, ultrasonic testing (UT), eddy current technique (ECT)) for the quality inspection. Furthermore, the current review aims to map the existing modeling approaches used to correlating measured weld characteristics and defects with the process parameters. Research gaps and implications of the quality assessment in laser welding are also described, and a future outlook of the research in the particular field is provided.


Laser welding Quality assessment Weld defects Monitoring techniques Modeling 



This work is under the framework of EU Project MAShES. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 637081. The dissemination of results herein reflects only the authors’ view, and the Commission is not responsible for any use that may be made of the information it contains.


  1. 1.
    Chryssolouris G, Papakostas N, Mavrikios D (2008) A perspective on manufacturing strategy: produce more with less. CIRP J Manuf Sci Technol 1(1):45–52CrossRefGoogle Scholar
  2. 2.
    Chryssolouris George (2013) Manufacturing systems: theory and practice. Springer Science & Business MediaGoogle Scholar
  3. 3.
    Tsoukantas G et al (2007) On optical design limitations of generalized two-mirror remote beam delivery laser systems: the case of remote welding. Int J Adv Manuf Technol 32(9–10):932–941CrossRefGoogle Scholar
  4. 4.
    Chryssolouris ELKE (2013) Laser machining: theory and practice. Springer Science & Business MediaGoogle Scholar
  5. 5.
    Stournaras A, Stavropoulos P, Salonitis K, Chryssolouris G (2008) Laser process monitoring: a critical review, (ICMR 08), 6th International Conference on Manufacturing Research, Uxbridge, pp. 425–435Google Scholar
  6. 6.
    Kaierle S (2008) Process monitoring and control of laser beam welding. Laser Technik Journal 5(3):41–43CrossRefGoogle Scholar
  7. 7.
    Katayama Seiji, and Kawahito Yousuke (2009) Elucidation of phenomena in high-power fiber laser welding and development of prevention procedures of welding defects. SPIE LASE: Lasers and Applications in Science and Engineering. International Society for Optics and PhotonicsGoogle Scholar
  8. 8.
    Shao Jiaqing and Yan Yong (2005) Review of techniques for on-line monitoring and inspection of laser welding. Journal of Physics: Conference Series. Vol. 15. No. 1. IOP PublishingGoogle Scholar
  9. 9.
    Zhao H, DebRoy T (2001) Pore formation during laser beam welding of die-cast magnesium alloy AM60B-mechanism and remedy. Weld J 80(8):204–210Google Scholar
  10. 10.
    Pastor M, et al. (1999) Porosity, underfill and magnesium lose during continuous wave Nd: YAG laser welding of thin plates of aluminum alloys 5182 and 5754. WELDING JOURNAL-NEW YORK- 78: 207-sGoogle Scholar
  11. 11.
    Madison JD, Aagesen LK (2012) Quantitative characterization of porosity in laser welds of stainless steel. Scr Mater 67(9):783–786CrossRefGoogle Scholar
  12. 12.
    Norris JT et al (2011) Effects of laser parameters on porosity formation: investigating millimeter scale continuous wave Nd: YAG laser welds. Weld J 90:198–203Google Scholar
  13. 13.
    Kamimuki K et al (2002) Prevention of welding defect by side gas flow and its monitoring method in continuous wave Nd: YAG laser welding. Journal of Laser applications 14(3):136–145CrossRefGoogle Scholar
  14. 14.
    Harooni M, Carlson B, Kovacevic R (2014) Detection of defects in laser welding of AZ31B magnesium alloy in zero-gap lap joint configuration by a real-time spectroscopic analysis. Opt Lasers Eng 56:54–66CrossRefGoogle Scholar
  15. 15.
    Katayama Seiji, Mizutani Masami, Matsunawa Akira (2003) Development of porosity prevention procedures during laser welding." Proc. SPIE. Vol. 4831Google Scholar
  16. 16.
    Rodil SS et al (2010) Laser welding defects detection in automotive industry based on radiation and spectroscopical measurements. Int J Adv Manuf Technol 49(1–4):133–145CrossRefGoogle Scholar
  17. 17.
    Sheikhi M, Malek Ghaini F, Assadi H (2015) Prediction of solidification cracking in pulsed laser welding of 2024 aluminum alloy. Acta Mater 82:491–502CrossRefGoogle Scholar
  18. 18.
    Lippold JC (1994) Solidification behavior and cracking susceptibility of pulsed-laser welds in austenitic stainless steels. Welding Journal Including Welding Research Supplement 73(6):129sGoogle Scholar
  19. 19.
    Ya Wei (2015) Laser materials interactions during cladding: analyses on clad formation, thermal cycles, residual stress and defects. Universiteit TwenteGoogle Scholar
  20. 20.
    Bergmann JP, Bielenin M, Feustel T (2015) Aluminum welding by combining a diode laser with a pulsed Nd: YAG laser. Welding in the World 59(2):307–315CrossRefGoogle Scholar
  21. 21.
    Gratzke U et al (1992) Theoretical approach to the humping phenomenon in welding processes. J Phys D Appl Phys 25(11):1640CrossRefGoogle Scholar
  22. 22.
    Ilar T et al (2012) Root humping in laser welding—an investigation based on high speed imaging. Phys Procedia 39:27–32CrossRefGoogle Scholar
  23. 23.
    Schempp P, et al. (2013) Influence of alloy and solidification parameters on grain refinement in aluminum weld metal due to inoculation. Trends in Welding Research 2012: Proceedings of the 9th International Conference. ASM InternationalGoogle Scholar
  24. 24.
    Gade R, Moeslund TB (2014) Thermal cameras and applications: a survey. Mach Vis Appl 25(1):245–262CrossRefGoogle Scholar
  25. 25.
    Tadamalle AP (2012) Review of real-time temperature measurement for process monitoring of laser conduction welding. Eng Sci Technol An Int J 2(5):946–950Google Scholar
  26. 26.
    Speka M et al (2008) The infrared thermography control of the laser welding of amorphous polymers. NDT & E International 41(3):178–183CrossRefGoogle Scholar
  27. 27.
    Chen Z, Gao X (2014) Detection of weld pool width using infrared imaging during high-power fiber laser welding of type 304 austenitic stainless steel. Int J Adv Manuf Technol 74(9–12):1247–1254CrossRefGoogle Scholar
  28. 28.
    Bardin F et al (2005) Process control of laser conduction welding by thermal imaging measurement with a color camera. Appl Opt 44(32):6841–6848CrossRefGoogle Scholar
  29. 29.
    Bardin F et al (2005) Closed-loop power and focus control of laser welding for full-penetration monitoring. Appl Opt 44(1):13–21CrossRefGoogle Scholar
  30. 30.
    You DY, Gao XD, Katayama S (2014) Review of laser welding monitoring. Sci Technol Weld Join 19(3):181–201CrossRefGoogle Scholar
  31. 31.
    Hutter Franz X., et al. (2009) A 0.25 μm logarithmic CMOS imager for emissivity-compensated thermography. Solid-State Circuits Conference-Digest of Technical Papers, 2009. ISSCC 2009. IEEE International. IEEEGoogle Scholar
  32. 32.
    Köhler H, Thomy C, Vollertsen F (2016) Contact-less temperature measurement and control with applications to laser cladding. Welding in the World 60(1):1–9CrossRefGoogle Scholar
  33. 33.
    Kim C-H, Ahn D-C (2012) Coaxial monitoring of keyhole during Yb: YAG laser welding. Opt Laser Technol 44(6):1874–1880CrossRefGoogle Scholar
  34. 34.
    Huang W, Kovacevic R (2011) A laser-based vision system for weld quality inspection. Sensors 11(1):506–521CrossRefGoogle Scholar
  35. 35.
    Saeed G, Zhang YM (2007) Weld pool surface depth measurement using a calibrated camera and structured light. Meas Sci Technol 18(8):2570CrossRefGoogle Scholar
  36. 36.
    Zhang Y, Gao X (2014) Analysis of characteristics of molten pool using cast shadow during high-power disk laser welding. Int J Adv Manuf Technol 70(9–12):1979–1988CrossRefGoogle Scholar
  37. 37.
    Abt F et al (2011) Camera based closed loop control for partial penetration welding of overlap joints. Phys Procedia 12:730–738CrossRefGoogle Scholar
  38. 38.
    Kawahito Y, Mizutani M, Katayama S (2007) Investigation of high-power fiber laser welding phenomena of stainless steel. TRANSACTIONS-JWRI 36(2):11Google Scholar
  39. 39.
    Tenner F et al (2015) Experimental approach for quantification of fluid dynamics in laser metal welding. Journal of Laser Applications 27(S2):S29003CrossRefGoogle Scholar
  40. 40.
    Gao X-d, Qian WEN, Katayama S (2013) Analysis of high-power disk laser welding stability based on classification of plume and spatter characteristics. Trans Nonferrous Metals Soc China 23(12):3748–3757CrossRefGoogle Scholar
  41. 41.
    Tenner F et al (2015) Analysis of the correlation between plasma plume and keyhole behavior in laser metal welding for the modeling of the keyhole geometry. Opt Lasers Eng 64:32–41CrossRefGoogle Scholar
  42. 42.
    Volpp Joerg, Srowig Jennifer, Vollertsen Frank. (2016) Spatters during laser deep penetration welding with a bifocal optic. Advanced materials research. Vol. 1140. Trans Tech PublicationsGoogle Scholar
  43. 43.
    Purtonen T, Kalliosaari A, Salminen A (2014) Monitoring and adaptive control of laser processes. Phys Procedia 56:1218–1231CrossRefGoogle Scholar
  44. 44.
    Voelkel DD, Mazumder J (1990) Visualization of a laser melt pool. Appl Opt 29(12):1718–1720CrossRefGoogle Scholar
  45. 45.
    Al-Habaibeh A, et al. (2004) A novel approach for quality control system using sensor fusion of infrared and visual image processing for laser sealing of food containers. Measurement Science and Technology 15.10Google Scholar
  46. 46.
    von Witzendorff P et al (2015) Using pulse shaping to control temporal strain development and solidification cracking in pulsed laser welding of 6082 aluminum alloys. J Mater Process Technol 225:162–169CrossRefGoogle Scholar
  47. 47.
    Dorsch Friedhelm, et al. (2012) NIR-camera-based online diagnostics of laser beam welding processes. SPIE LASE. International Society for Optics and PhotonicsGoogle Scholar
  48. 48.
    Dorsch F, Braun H, Keßler S, Magg W (2012) Process sensor systems for laser beam welding. Laser Technik J 9:24–28CrossRefGoogle Scholar
  49. 49.
    Zeng H et al (2001) Wavelet analysis of acoustic emission signals and quality control in laser welding. Journal of Laser Applications 13(4):167–173MathSciNetCrossRefGoogle Scholar
  50. 50.
    Li L (2002) A comparative study of ultrasound emission characteristics in laser processing. Appl Surf Sci 186(1):604–610CrossRefGoogle Scholar
  51. 51.
    Lee S, Ahn S, Park C (2014) Analysis of acoustic emission signals during laser spot welding of SS304 stainless steel. J Mater Eng Perform 23(3):700–707CrossRefGoogle Scholar
  52. 52.
    Kercel Stephen W, et al. (1999) In-process detection of weld defects using laser-based ultrasound. Proc. SPIE. Vol. 3852Google Scholar
  53. 53.
    Lott P et al (2011) Design of an optical system for the in situ process monitoring of selective laser melting (SLM). Phys Procedia 12:683–690CrossRefGoogle Scholar
  54. 54.
    Vallejo, David Diego (2014) Spectroscopic investigations of plasma emission induced during laser material processing. epubliGoogle Scholar
  55. 55.
    Webster PJL et al. (2015) Three-dimensional, multi-factor monitoring and control of laser keyhole welding by inline coherent imagingGoogle Scholar
  56. 56.
    Papazoglou DG, Papadakis V, Anglos D (2004) In situ interferometric depth and topography monitoring in LIBS elemental profiling of multi-layer structures. J Anal At Spectrom 19(4):483–488CrossRefGoogle Scholar
  57. 57.
    Park YW et al (2002) Real time estimation of CO 2 laser weld quality for automotive industry. Opt Laser Technol 34(2):135–142CrossRefGoogle Scholar
  58. 58.
    Zhang X et al (2004) Relationship between weld quality and optical emissions in underwater Nd: YAG laser welding. Opt Lasers Eng 41(5):717–730CrossRefGoogle Scholar
  59. 59.
    You D, Gao X, Katayama S (2013) Multiple-optics sensing of high-brightness disk laser welding process. NDT & E International 60:32–39CrossRefGoogle Scholar
  60. 60.
    Kaplan Alexander FH, Norman Peter, Eriksson Ingemar. (2009) Analysis of the keyhole and weld pool dynamics by imaging evaluation and photodiode monitoring. Proceedings of LAMP2009—the 5th International Congress on Laser Advanced Materials ProcessingGoogle Scholar
  61. 61.
    Sanders PG et al (1998) Real-time monitoring of laser beam welding using infrared weld emissions. Journal of laser Applications 10(5):205–211CrossRefGoogle Scholar
  62. 62.
    Sanders PG, et al. (1997) Capabilities of infrared weld monitor. No. ANL/TD/CP--93200; CONF-971149--. Argonne National Lab., IL (United States)Google Scholar
  63. 63.
    Kim J-T et al (2003) Laser welding quality monitoring with an optical fiber system. Journal of the Optical Society of Korea 7(3):193–196CrossRefGoogle Scholar
  64. 64.
    Sibillano T et al (2006) Correlation spectroscopy as a tool for detecting losses of ligand elements in laser welding of aluminium alloys. Opt Lasers Eng 44(12):1324–1335CrossRefGoogle Scholar
  65. 65.
    Mrňa L et al (2012) Feedback control of laser welding based on frequency analysis of light emissions and adaptive beam shaping. Phys Procedia 39:784–791CrossRefGoogle Scholar
  66. 66.
    Sibillano T et al (2007) Real-time monitoring of laser welding by correlation analysis: the case of AA5083. Opt Lasers Eng 45(10):1005–1009CrossRefGoogle Scholar
  67. 67.
    Rizzi D et al (2011) Spectroscopic, energetic and metallographic investigations of the laser lap welding of AISI 304 using the response surface methodology. Opt Lasers Eng 49(7):892–898CrossRefGoogle Scholar
  68. 68.
    Konuk AR et al (2011) Process control of stainless steel laser welding using an optical spectroscopic sensor. Phys Procedia 12:744–751CrossRefGoogle Scholar
  69. 69.
    Sebestova H et al (2012) Non-destructive real time monitoring of the laser welding process. J Mater Eng Perform 21(5):764–769CrossRefGoogle Scholar
  70. 70.
    Sibillano T et al (2012) Closed loop control of penetration depth during CO2 laser lap welding processes. Sensors 12(8):11077–11090CrossRefGoogle Scholar
  71. 71.
    Zaeh MF, Huber S (2011) Characteristic line emissions of the metal vapor during laser beam welding. Prod Eng 5(6):667–678CrossRefGoogle Scholar
  72. 72.
    Smurov Igor (2001) Pyrometry applications in laser machining. Laser-assisted microtechnology 2000. International Society for Optics and PhotonicsGoogle Scholar
  73. 73.
    Bertrand P, Smurov I, Grevey D (2000) Application of near infrared pyrometry for continuous Nd: YAG laser welding of stainless steel. Appl Surf Sci 168(1):182–185CrossRefGoogle Scholar
  74. 74.
    Smurov Igor (2007) Laser process optical sensing and control." IV International WLT-Conference on Lasers in ManufacturingGoogle Scholar
  75. 75.
    Doubenskaia M, et al. (2007) On-line optical monitoring of Nd: YAG laser lap welding of Zn-coated steel sheets. IV International WLT-Conference on Lasers in ManufacturingGoogle Scholar
  76. 76.
    Zhang Pu, et al. (2008) Real-time monitoring of laser welding based on multiple sensors. Control and Decision Conference, 2008. CCDC 2008. Chinese. IEEEGoogle Scholar
  77. 77.
    Farson D, Ali A, SANG YAN (1998) Relationship of optical and acoustic emissions to laser weld penetration. Weld J 77(4):142-sGoogle Scholar
  78. 78.
    Kamimuki K et al (2003) Behavior of monitoring signals during detection of welding defects in YAG laser welding. Study of monitoring technology for YAG laser welding (report 2). Weld Int 17(3):203–210CrossRefGoogle Scholar
  79. 79.
    Nakamura S et al (2000) Detection technique for transition between deep penetration mode and shallow penetration mode in CO2 laser welding of metals. J Phys D Appl Phys 33(22):2941CrossRefGoogle Scholar
  80. 80.
    You D, Gao X, Katayama S (2015) A novel stability quantification for disk laser welding by using frequency correlation coefficient between multiple-optics signals. Mechatronics, IEEE/ASME Transactions on 20(1):327–337CrossRefGoogle Scholar
  81. 81.
    Norman Peter, et al. (2008) Correlation between photodiode monitoring and high speed imaging of the dynamics causing laser welding defects. International Congress on Applications of Lasers & Electro-Optics: 20/10/2008–23/10/2008. Laser institute of AmericaGoogle Scholar
  82. 82.
    Norman P, Engström H, Kaplan AFH (2008) Theoretical analysis of photodiode monitoring of laser welding defects by imaging combined with modelling. J Phys D Appl Phys 41(19):195502CrossRefGoogle Scholar
  83. 83.
    Mickel PM, Kuhl M, Seidel M (2007) Quality and process control of laser welding using multisensory systems and methods of pattern recognition. Proc. LANE, Germany: 957–966Google Scholar
  84. 84.
    Clijsters S et al (2014) In situ quality control of the selective laser melting process using a high-speed, real-time melt pool monitoring system. Int J Adv Manuf Technol 75(5–8):1089–1101CrossRefGoogle Scholar
  85. 85.
    Vänskä M et al (2013) Effects of welding parameters onto keyhole geometry for partial penetration laser welding. Phys Procedia 41:199–208CrossRefGoogle Scholar
  86. 86.
    Du Dong, et al. (2007) Automatic inspection of weld defects with X-ray real-time imaging. Robotic welding, intelligence and automation. Springer Berlin Heidelberg. 359–366Google Scholar
  87. 87.
    Katayama S, Kawahito Y, Mizutani M (2007) Collaboration of physical and metallurgical viewpoints for understanding and process development of laser welding. ICALEO 2007 Congress Proceedings (Proceedings of the 26th International Congress on Applications of Lasers & Electro-Optics), LIA, OrlandoGoogle Scholar
  88. 88.
    Naito Y, Mizutani M, Katayama S (2006) Effect of oxygen in ambient atmosphere on penetration characteristics in single yttrium–aluminum–garnet laser and hybrid welding. Journal of laser applications 18(1):21–27CrossRefGoogle Scholar
  89. 89.
    Chryssolouris G, Yablon A (1993) Depth prediction in laser machining with the aid of surface temperature measurements. CIRP Annals-Manufacturing Technology 42(1):205–207CrossRefGoogle Scholar
  90. 90.
    Lankalapalli KN, Tu JF, Gartner M (1996) A model for estimating penetration depth of laser welding processes. J Phys D Appl Phys 29(7):1831CrossRefGoogle Scholar
  91. 91.
    Dowden J, Kapadia P (1995) A mathematical investigation of the penetration depth in keyhole welding with continuous CO2 lasers. J Phys D Appl Phys 28(11):2252CrossRefGoogle Scholar
  92. 92.
    Lampa C et al (1997) An analytical thermodynamic model of laser welding. J Phys D Appl Phys 30(9):1293CrossRefGoogle Scholar
  93. 93.
    Volpp J, Vollertsen F (2016) Keyhole stability during laser welding—part I: modeling and evaluation. Prod Eng 10(4–5):443–457CrossRefGoogle Scholar
  94. 94.
    Kim J-D (1990) Prediction of the penetration depth in laser beam welding. KSME journal 4(1):32–39CrossRefGoogle Scholar
  95. 95.
    Kazemi K, Goldak JA (2009) Numerical simulation of laser full penetration welding. Comput Mater Sci 44(3):841–849CrossRefGoogle Scholar
  96. 96.
    Pastras G et al (2015) A numerical approach to modeling keyhole laser welding. Int J Adv Manuf Technol 78(5–8):723–736CrossRefGoogle Scholar
  97. 97.
    GuoMing H, Jian Z, JianQang L (2007) Dynamic simulation of the temperature field of stainless steel laser welding. Mater Des 28(1):240–245CrossRefGoogle Scholar
  98. 98.
    Zhao S et al (2011) Numerical simulation and experimental investigation of laser overlap welding of Ti6Al4V and 42CrMo. J Mater Process Technol 211(3):530–537CrossRefGoogle Scholar
  99. 99.
    Abderrazak K et al (2009) Numerical and experimental study of molten pool formation during continuous laser welding of AZ91 magnesium alloy. Comput Mater Sci 44(3):858–866CrossRefGoogle Scholar
  100. 100.
    Mishra S, Chakraborty S, DebRoy T (2005) Probing liquation cracking and solidification through modeling of momentum, heat, and solute transport during welding of aluminum alloys. J Appl Phys 97(9):094912CrossRefGoogle Scholar
  101. 101.
    Pang S, Chen W, Wang W (2014) A quantitative model of keyhole instability induced porosity in laser welding of titanium alloy. Metall Mater Trans A 45(6):2808–2818CrossRefGoogle Scholar
  102. 102.
    Zhao H, DebRoy T (2003) Macroporosity free aluminum alloy weldments through numerical simulation of keyhole mode laser welding. J Appl Phys 93(12):10089–10096CrossRefGoogle Scholar
  103. 103.
    Acherjee B et al (2011) Application of grey-based Taguchi method for simultaneous optimization of multiple quality characteristics in laser transmission welding process of thermoplastics. Int J Adv Manuf Technol 56(9–12):995–1006CrossRefGoogle Scholar
  104. 104.
    Olabi AG et al (2006) An ANN and Taguchi algorithms integrated approach to the optimization of CO 2 laser welding. Adv Eng Softw 37(10):643–648CrossRefGoogle Scholar
  105. 105.
    Anawa EM, Olabi A-G (2008) Using Taguchi method to optimize welding pool of dissimilar laser-welded components. Opt Laser Technol 40(2):379–388CrossRefGoogle Scholar
  106. 106.
    Pan LK et al (2005) Optimization of Nd: YAG laser welding onto magnesium alloy via Taguchi analysis. Opt Laser Technol 37(1):33–42CrossRefGoogle Scholar
  107. 107.
    Casalino G, Curcio F, Memola Capece Minutolo F (2005) Investigation on Ti6Al4V laser welding using statistical and Taguchi approaches. J Mater Process Technol 167(2):422–428CrossRefGoogle Scholar
  108. 108.
    Tzeng Y-F (2000) Process characterization of pulsed Nd: YAG laser seam welding. Int J Adv Manuf Technol 16(1):10–18CrossRefGoogle Scholar
  109. 109.
    Park YW, Rhee S (2008) Process modeling and parameter optimization using neural network and genetic algorithms for aluminum laser welding automation. Int J Adv Manuf Technol 37(9–10):1014–1021CrossRefGoogle Scholar
  110. 110.
    Jeng J-Y, Mau T-F, Leu S-M (2000) Prediction of laser butt joint welding parameters using back propagation and learning vector quantization networks. J Mater Process Technol 99(1):207–218CrossRefGoogle Scholar
  111. 111.
    Naso D, Turchiano B, Pantaleo P (2005) A fuzzy-logic based optical sensor for online weld defect-detection. IEEE transactions on Industrial Informatics 1(4):259–273CrossRefGoogle Scholar
  112. 112.
    Luo M, Shin YC (2015) Estimation of keyhole geometry and prediction of welding defects during laser welding based on a vision system and a radial basis function neural network. Int J Adv Manuf Technol 81(1–4):263–276CrossRefGoogle Scholar
  113. 113.
    Luo H et al (2005) Application of artificial neural network in laser welding defect diagnosis. J Mater Process Technol 170(1):403–411CrossRefGoogle Scholar
  114. 114.
    Huang W, Kovacevic R (2011) A neural network and multiple regression method for the characterization of the depth of weld penetration in laser welding based on acoustic signatures. J Intell Manuf 22(2):131–143CrossRefGoogle Scholar
  115. 115.
    Park H, Rhee S, Kim D (2001) A fuzzy pattern recognition based system for monitoring laser weld quality. Meas Sci Technol 12(8):1318CrossRefGoogle Scholar
  116. 116.
    Park H, Rhee S (1999) Analysis of mechanism of plasma and spatter in CO 2 laser welding of galvanized steel. Opt Laser Technol 31(2):119–126CrossRefGoogle Scholar
  117. 117.
    Park H, Rhee S (1999) Estimation of weld bead size in CO2 laser welding by using multiple regression and neural network. Journal of Laser Applications 11(3):143–150CrossRefGoogle Scholar
  118. 118.
    Passini A et al (2011) Ultrasonic inspection of AA6013 laser welded joints. Mater Res 14(3):417–422CrossRefGoogle Scholar
  119. 119.
    Salzburger HJ, Mohrbacher H (2002) In-line quality control of laser welds of tailored blanks by couplant free ultrasonic inspection. European Federation for Non-Destructive Testing (EFNDT), European Conference on Nondestructive Testing (8)Google Scholar
  120. 120.
    Miller M et al (2002) Development of automated real-time data acquisition system for robotic weld quality monitoring. Mechatronics 12(9):1259–1269CrossRefGoogle Scholar
  121. 121.
    Kita Akio (2005) Measurement of weld penetration depth using non-contact ultrasound methodsGoogle Scholar
  122. 122.
    Rogge Matthew Douglas (2009) In-process sensing of weld penetration depth using non-contact laser ultrasound systemGoogle Scholar
  123. 123.
    Dixon S, Edwards C, Palmer SB (1999) A laser–EMAT system for ultrasonic weld inspection. Ultrasonics 37(4):273–281CrossRefGoogle Scholar
  124. 124.
    Mi B, Ume C (2006) Real-time weld penetration depth monitoring with laser ultrasonic sensing system. J Manuf Sci Eng 128(1):280–286CrossRefGoogle Scholar
  125. 125.
    Mai TA, Spowage AC (2004) Characterization of dissimilar joints in laser welding of steel–kovar, copper–steel and copper–aluminum. Mater Sci Eng A 374(1):224–233CrossRefGoogle Scholar
  126. 126.
    Zhang Xiao-Guang, Xu Jian-Jian, Ge Guang-Ying (2004) Defects recognition on X-ray images for weld inspection using SVM. Machine Learning and Cybernetics, 2004. Proceedings of 2004 International Conference on. Vol. 6. IEEEGoogle Scholar
  127. 127.
    Lashkia V (2001) Defect detection in X-ray images using fuzzy reasoning. Image Vis Comput 19(5):261–269CrossRefGoogle Scholar
  128. 128.
    Fu Y et al (1998) Laser alloying of aluminum alloy AA 6061 with Ni and Cr. Part 1. Optimization of processing parameters by X-ray imaging. Surf Coat Technol 99(3):287–294MathSciNetCrossRefGoogle Scholar
  129. 129.
    Boley M et al (2013) X-ray and optical videography for 3D measurement of capillary and melt pool geometry in laser welding. Phys Procedia 41:488–495CrossRefGoogle Scholar
  130. 130.
    Zosch Antje, Seidel Martin (2006) Nondestructive testing of laser welded lap seams by eddy current technique, ECNDTGoogle Scholar
  131. 131.
    Ho SK, White RM, Lucas J (1990) A vision system for automated crack detection in welds. Meas Sci Technol 1(3):287CrossRefGoogle Scholar
  132. 132.
    Todorov E, et al. (2013) Inspection of laser welds with array eddy current. AIP Conference Proceedings. Vol. 1511Google Scholar
  133. 133.
    Gilblas R, et al. (2011) Thermoreflectometry: a new system to determine the true temperature fields on surface with unknown emissivity. SPIE Defense, Security, and Sensing. International Society for Optics and PhotonicsGoogle Scholar
  134. 134.
    Hagen N, Kudenov MW (2013) Review of snapshot spectral imaging technologies. Opt Eng 52(9):090901–090901CrossRefGoogle Scholar

Copyright information

© The Author(s) 2018

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  • John Stavridis
    • 1
  • Alexios Papacharalampopoulos
    • 1
  • Panagiotis Stavropoulos
    • 1
    Email author
  1. 1.Laboratory for Manufacturing Systems and Automation, Department of Mechanical Engineering and AeronauticsUniversity of PatrasPatrasGreece

Personalised recommendations