Laser Powder Bed Fusion of Stainless Steel 316L for Rectangular Micropillar Array with High Geometrical Accuracy and...

Area of Science:

• Materials Science and Engineering
• Additive Manufacturing
• Surface Engineering

Background:

• Laser Powder Bed Fusion (LPBF) is a key additive manufacturing technology.
• Fabricating precise surface microstructures like micropillar arrays is crucial for component performance.
• SS316L is a widely used material in various industrial applications.

Purpose of the Study:

• To investigate the manufacturability of SS316L components with rectangular micropillar arrays using LPBF.
• To determine the effects of laser energy density, micropillar dimensions, and build direction on fabrication quality.
• To optimize LPBF process parameters for defect-free micropillar array production.

Main Methods:

• Fabrication of SS316L micropillars (200-800 μm width) using LPBF with varied energy densities and build directions (0°, 45°).
• Microstructural analysis using Scanning Electron Microscopy (SEM) and Optical Microscopy.
• Evaluation of geometrical accuracy, densification, and Vickers hardness.

Main Results:

• An optimal volumetric laser energy density of 105 J/mm³ was identified for minimizing defects.
• Micropillars fabricated at 0° and 45° build directions exhibited stable morphology and accuracy.
• Fabricated micropillars showed dimensional deviations (larger width/pitch, smaller gaps) compared to CAD designs.
• Hardness was influenced by micropillar size, energy density, and build direction.

Conclusions:

• Successful fabrication of SS316L rectangular micropillars (200-800 μm) via LPBF is demonstrated.
• The study provides optimal process parameters (105 J/mm³, 0°/45° build angles) for high-quality micropillar array production.
• Understanding parameter effects is key for controlling surface topography and material properties in LPBF.