Methods of Laser Beam Shaping and Its Advantages in Metal Laser Additive Manufacturing: A Review
摘要
Industry is increasingly using additively manufactured components in the field of laser powderbed fusion (L-PBF). When it is necessary to manufacture complex component geometries in small quantities, common processes like L-PBF come into play. Often, the costs of subtractive, conventional manufacturing processes and the expensive post-processing of the workpiece are higher than when using a generative build-up. However, the use of these conventional manufacturing processes remains common. This is due to the extensive knowledge and research on the mechanical properties and material behavior during processing. In contrast, the material behavior of the metal powder is significantly and seemingly uncontrollably influenced by high heating and cooling rates, dynamic melt pool behavior and spatter formation. The standard Gaussian energy density distribution of a laser beam has certain physical limits when processing powder material. This is where beam shaping comes into play. Specially manipulated laser beam intensity distributions have a direct influence on the behavior of the molten pool, making the mechanical properties of the material more controllable. This paper, therefore, deals with various methods of beam shaping. This paper summarizes potential defects in an additively manufactured component and demonstrates how shaped laser beams can minimize these defects. The last chapter shows a schematic test setup that should lay the foundation for future research on this topic.