Computer Assisted Manufacturing (CAM) plays an important role in the process chain for Laser Material Processing. Based on a digital model of the component NC programs for the control of the mechanical axes and the optical systems are generated.
For Laser Metal Deposition (LMD) processes Fraunhofer ILT developed the software “LMDCAM“. This software is a powerful tool path planning instrument for repairing and additive manufacturing of components. It is optimized for working with large data files (e. g. triangulated data acquired by a measuring device). The user is able to interact with all entities (like CAD data and the tool path) and thereby complex and individual tasks can be solved. After generating tool paths the resulting machine movement can be checked for collisions or exceeded axis velocities. For this task the software includes a build-in machine simulation tool. Using the included programmable post processor tool paths can be exported as NC programs which can also support multi-axes systems (e. g. robots).
For laser micro structuring galvanometric laser scanners for laser beam deflection and short pulse laser sources are used. Compared to LMD laser micro structuring is a subtractive manufacturing process where the material is ablated locally. Fraunhofer ILT developed the software “SliceGen“ specially adapted to the laser structuring process. A CAD model is filled with tool paths layer by layer. Each layer can be tiled to the limited working volume of the laser scanner. The tiles can be distributed randomly to avoid visible boundaries. The software is also able to generate tool paths for form correction by measured data. For this application the tool paths for removing the surplus volume are calculated based on the desired and current topography.
For laser polishing Fraunhofer ILT developed the software “TP4“ to convert data, generated by a conventional CAM software (for finishing milling), into tool paths which are suitable for the laser polishing process. As in laser structuring, this process also uses a laser scanner for fast laser spot positioning. Therefore the required total movement is split into two parts. The fast movement is assigned to the laser scanner while the slow movement is assigned to the slower mechanical axis system (usually a 5-axis system). The software calculates the superposed movement and generates separate NC programs for the laser scanner and the mechanical axes. Machine programming in work piece coordinates is also supported which allows the usage of a measuring probe. Furthermore several process strategies are implemented in the software to ensure constant process conditions also on curved surfaces. To meet the various requirements for different applications and setups the software has access to a database where many process parameters for different materials, applications and kinematics are stored.