Investigation of build strategies for microfeatures fabrication using laser powder bed fusion

Abstract

Modifying the surface topography by fabricating the microfeatures on-top of interacting surfaces has the potential to enhance the tribological behavior of mechanical components having sliding motion. In the additive manufacturing process, Laser powder bed fusion process (LPBF) is chosen to fabricate microfeatures for metals. In LPBF, microfeature characteristics are based on the energy supplied and strategies used for fabrication. In this work, a single layer single track (SLST) experiment is carried out for a different combination of the laser power and scanning speed for fabricating continuous and uniform track width with good shape controllability. Further, the interaction between the lateral and vertical deposition to a single track is also analyzed by using single layer double track (SLDT) and double layer single track (DLST) strategies. It has been found that the LPBF process parameters have a significant influence on the track's morphology and its geometry irrespective of the build strategies. The continuous and uniform tracks are formed when the LED is greater than 0.3 J/mm for investigated build strategies. The microfeatures of width 150 μm to 300 μm and height 40 μm is recommended to fabricate by SLST strategy whereas for 60 μm height of microfeature DLST strategy is recommended. If the microfeatures width is greater than 300 μm then SLDT strategy is recommended. SLST and DLST show good control on the microfeatures characteristics as compared to SLDT strategy.