Table of Contents
Overview of fiber laser welding
The fiber laser welding technology keeps expanding as a promising method with advancements in weld quality, dependability, and efficiency. Most fiber laser welding applications are regarded as autogenous, which means the weld is created entirely by melting parts of the base metal, and no additional filler wire or powder is applied.
Applications and need for filler material
Welding applications of a laser beam are almost always autogenous for a huge variety of materials. There are specific materials and challenging applications of laser systems that need the use of filler material in the welding process, resulting in great improvements.
Advantages of fiber laser welding with filler material
The improved fiber laser system provides better joint fit-up tolerance, avoiding solidification cracking during the welding process. The laser system welding changes the chemical composition or the microstructure of the weld metal to obtain suitable mechanical properties, as well as improves the weld profile.
Types of filler material
It is possible to use powder or wire filler material during laser beam welding. Most industrial laser system applications are based on wire use. The main reason for its use is regarded as low cost because generally, powder feedstock is more expensive than wire for most materials.
Factors affecting quality and process
Fiber laser welding with filler wire depends on several conditions that define quality, process speed, and cost. For instance, “the wire feed rate is dependent on welding speed, the cross-sectional area of the gap between the joint face and cross-sectional area of the filler wire.” The application of filler wire in a laser system usually leads to a 10-20% reduction in welding speed, for a given laser beam power, to compensate for the fiber laser energy that has to be used to melt the wire.
Laser beam and filler wire interaction
Laser beam-filler wire interaction also plays a crucial role. The short length of the wire interferes with the wire from being melted at the initial part of the bead; therefore, the laser beam directly leads to the material being melted. The long length of wire, in turn, causes the extended wire end to be pressed against the plate surface.
Importance of focused spot size
It is necessary to pay careful attention to the focused spot size: it should be close to the filler wire diameter because a small spot size of the fiber laser system compared to the wire diameter results in welds with porosity because the filler wire has not melted properly.
Applications and effectiveness
Finally, the fiber laser technology has been tested and demonstrated that fiber laser welding, applying filler wire, provides effective in producing high-quality, robust welds with improved fit-up, reduced weld cracking, and better weld profile. It is possible to use fiber laser systems in a wide range of applications, such as aerospace, automotive, and many industrial fabricating applications.