112 P. Kah o  TfQASUT GdeTi UAdUb B @dT Rev. Adv. Mater. Sci. 30 (2012) 112-132 Corresponding author: P. Kah, e-mail: paul.kah@lut.fi OVERVIEW OF THE EXPLORATION STATUS OF LASER-ARC HYBRID WELDING PROCESSES P. Kah Lappeenranta University of Technology, LUT Mechanical PL 20, Lappeenranta 53851, Finland Received: November 18, 2011 Abstract. AUdQ? YATecdbYUc CbBTeSYAW dXYS[ cUSdYBAc XQfU cXBgA YASbUQcYAW YAdUbUcd YA ?QcUbsQbS hybrid welding processes because of their clear advantages compared with the individual CbBSUccUc BV QedBWUABec ?QcUb gU?TYAW QAT QbS gU?TYAW CAU ]QZBb RUAUVYd BV ?QcUbsQbS XiRbYT welding is that compared to autogenous laser, welding joints with larger gaps can be welded with acceptable quality. The laser-arc hybrid welding process has good potential to extend the field of applications of laser technology, and provide significant improvements in weld quality and process efficiency in manufacturing applications. The objective of this review is to present a set- eC VBb ?QcUbsQbS XiRbYT gU?TYAW CbBSUccUc QAT YAdbBTeSU Q ]UdXBTYSQ? SB]CQbYcBA BV dXU SXBcUA parameters. The research describes the principles, means and applications of different types of ?QcUbsQbS XiRbYT gU?TYAW CbBSUccUc Based on a review of the current knowledge base, important areas for further research are also identified. The study uses quantitative and qualitative research methods which include in-depth, interpretive analyses of results from a number of research groups. In the interpretive analysis, the emphasis is placed on the relevance and usefulness of the investigative results drawn from other research publications. HXU bUce?dc BV dXYc cdeTi SBAdbYRedU dB bUcUQbSX BA ?QcUbsQbS XiRbYT gU?TYAW Ri YASbUQcYAW eATUbcdQATYAW BV XBg B?T QAT AUg CUbcCUSdYfUc BA ?QcUbsQbS XiRbYT gU?TYAW QbU UfYTUASUT YA YATecdbi HXU bUcUQbSX ]UdXBTB?BWi QCC?YUT CUb]Ydc SBAdYAeUT UhC?BbQdYBA BV XBg ?QcUbsQbS hybrid welding and its various process factors influence the overall quality of the weld. The study CbBfYTUc Q WBBT VBeATQdYBA VBb VedebU bUcUQbSX SbUQdUc Y]CbBfUT QgQbUAUcc BV dXU ?QcUbsQbS hybrid welding process, and assists the metal industry in maximizing welding productivity. 1. INTRODUCTION @QcUbsQbS XiRbYT gU?TYAW Yc Q CbBSUcc YA gXYSX dXU arc provides energy and molten metal, if filler wire is added, whilst the laser produces characteristics such as deep penetration, arc stability and extension of the root. It is, thus, possible to increase productivity and improve weld quality simultaneously [1,2] in comparison to welds produced with each process independently. This combination of heat sources (Fig. 1) has been receiving considerable attention because it can offer many advantages [3]. These advantages are, for example, deeper penetration, higher welding speeds, wider gap tolerance, better weld bead surface appearance, and reduced welding defects, leading to a smaller Q]BeAd BV CBbBcYdi c dXU XUQd YACed BV ?QcUb s QbS hybrid welding (LAHW) is greater than in laser welding, but much smaller than in MAG arc welding, a relatively narrow weld and restricted heat affected zone (HAZ) is obtained, which can minimize distortion [2,4-12]. These potential benefits can, however, only be achieved when the processes are correctly combined. Laser-arc hybrid welding is not a new technology; the combination of laser light and an electrical arc in an amalgamated welding process dates back to