Some optimization strategies for tool path generation in 3D laser metal deposition

Laser direct metal deposition has proven to be successful in the manufacturing of 3D parts. In this process, the required geometry is built up layer by layer on overlapping laser clad beads. However, some problems are often encountered regarding surface finish and dimensional accuracy. These are mainly caused by heat accumulation effects during the process (resulting in changes in material temperature and powder catchment efficiency) and/or inadequate tool path trajectories and scanning parameters. All these factors lead to defects in the manufactured 3D part, particularly when bulk solid structures (as opposed to hollow) are involved in the process. In this work we test and discuss the effect of different tool path strategies in dealing with the above issues. Results will be presented on the laser 3D manufacturing of stainless steel parts. A monitoring device (online CMOS camera) will be used to supervise and get and better understanding of the deposition process under the different approaches.