A Numerical Study of Topography and Roughness of Sloped Surfaces Using Process Simulation Data for Laser Powder Bed...

Area of Science:

• Additive Manufacturing
• Materials Science
• Computational Engineering

Background:

• Additive manufacturing (AM) simulations are crucial for predicting potential issues in processes like laser powder bed fusion (L-PBF).
• Surface roughness significantly impacts part quality in L-PBF, but accurate simulation remains challenging.

Purpose of the Study:

• To calculate surface roughness using 3D surface topology from simulated L-PBF data.
• To evaluate the accuracy of L-PBF simulations in predicting surface roughness compared to experimental results.

Main Methods:

• Simulated L-PBF using discrete element method for powder spreading and Flow-3D for melting.
• Generated 3D representations of ten layers for two cases (pre- and post-contouring) at various linear energy densities (LED).
• Extracted and analyzed upskin, downskin, and side skin surfaces, calculating surface roughness (Sa) using MATLAB.

Main Results:

• 3D surface topology was generated from simulated thermal gradient data.
• Calculated Sa values for downskin surfaces from simulations were within the range of experimental results.
• The simulation's focus on melt pool depth and width correlated with the observed downskin roughness.

Conclusions:

• Simulations show potential for accurately predicting surface roughness in L-PBF.
• The study validates the use of physics-based simulations for estimating surface quality in additive manufacturing.
• Further refinement of simulation parameters can enhance prediction accuracy for all surfaces.