Laser Powder Bed Fusion Power Mapping for Corner Pore Control
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Solution Overview
Problem
Conventional laser powder bed fusion additive manufacturing machines face challenges in optimizing process parameters like laser power and speed to maintain consistent melt pool geometry, leading to defects such as pores during corner turns, which affect reproducibility and part quality.
Innovation Solution
A power map is created using a Proportional Integral Derivative (PID) controller to intelligently control laser power as it scans, adjusting parameters to maintain a constant melt pool depth and prevent defects by predicting and mitigating energy deposition during turns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional laser powder bed fusion machines use locked process parameters, then manufacturing simplicity is maintained, but manufacturing precision deteriorates due to pore defects during corner turns
Solution Approach 1:
The power map is generated in advance using a simulation model that predicts the optimal laser power requirements for each location on the part, including corner regions. This preliminary calculation allows the system to feed forward the optimized power profile before actual manufacturing, eliminating pore defects at corners without requiring complex real-time feedback control
Solution Approach 2:
The system dynamically adjusts the laser power parameter based on the pre-calculated power map, which specifies different power levels for different locations on the part. This allows the laser power to be optimized for each specific geometry (e.g., increased power at corners to prevent defects) while maintaining a relatively simple control architecture
2Manufacturing precision
If laser power is increased to maintain melt pool geometry, then manufacturing precision improves, but object-generated harmful factors worsen due to thermal residual stress
Solution Approach 1:
The power map applies different laser power levels to different locations on the part based on local geometric requirements. In corner regions where pores tend to form, the power is increased to maintain melt pool geometry. In other regions, the power is optimized to minimize thermal accumulation and residual stress. This localized optimization resolves the contradiction between maintaining melt pool depth and reducing thermal stress
3Manufacturing precision
If process parameters are optimized for corner turns, then manufacturing precision improves, but productivity deteriorates due to extended processing time
Solution Approach 1:
The power map is calculated in advance using a computational model, allowing the system to know the optimal power profile for the entire part before manufacturing begins. This eliminates the need for slow iterative trial-and-error optimization during actual building, as the optimized parameters are ready to be applied immediately
Solution Approach 2:
The system uses location-specific power parameters from the power map to optimize melting efficiency at corners without requiring excessive dwell time or repeated passes. The pre-calculated power profile ensures that each location receives exactly the right amount of energy, avoiding both under-melting (defects) and over-melting (time waste)
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach eliminates pore defects, enhances part quality, increases machine-to-machine reproducibility, reduces waste, and minimizes thermal residual stress, resulting in higher quality parts with reduced porosity and improved surface roughness.
Implementation Method 1
a laser that produces a laser beam... selected areas of a powder bed are solidified in a layer-by-layer manner to form a workpiece
Implementation Method 2
the laser beam path includes turning points... as the laser beam follows its path... creating a depression of molten metal
Implementation Method 3
A power map is created using a Proportional Integral Derivative (PID) controller to intelligently control laser power... to maintain a constant melt pool depth
Data Source
AI summary
A laser powder bed fusion additive manufacturing system for producing a part by creating a power map that is an intelligent feed forward model to control the laser powder bed fusion additive manufacturing for producing the part and using the power map to control the laser powder bed fusion additive manufacturing for producing the part. This includes an apparatus for producing a part including a powder bed, a laser that produces a laser beam, a proportional integral derivative controller that creates a power map that describes laser power requirements as the laser moves along a path, wherein the laser power requirements prevent defects in the part.