Fiber-Array Multi-Beam Laser Shaping for Metal AM Thermal Control
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Solution Overview
Problem
Current laser additive manufacturing (LAM) systems face challenges due to the lack of active and adaptive control of laser beam spatiotemporal characteristics and inadequate in situ sensing, leading to issues with micro-structure improvement, surface finish, residual stress mitigation, and processing speed, particularly with single-point processing techniques that result in thermal gradients, balling effects, and variability in heat dissipation.
Innovation Solution
The implementation of an adaptive multi-beam fiber-array laser additive manufacturing system (AMBFA-LAM) that utilizes a multi-beam fiber array laser head with integrated sensing modules for real-time characterization and control of laser power distribution, enabling simultaneous pre-heating, melting, and post-heating of metal powders with adaptive beam shaping and steering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single laser beam is used for selective laser melting, then the system is simple to operate, but thermal gradients and balling effects occur leading to poor surface finish and micro-structure control
Solution Approach 1:
The single laser beam is segmented into multiple independent beams that can be individually controlled. Each beam can be focused to different depths and positions, allowing simultaneous multi-point processing that reduces thermal gradients and eliminates balling effects while improving surface finish and micro-structure control.
Solution Approach 2:
The system transitions from single-point processing in one dimension to multi-point processing in three dimensions by controlling multiple beams at different focal depths and spatial positions simultaneously, enabling complex 3D micro-structure control and improved surface finish.
2Productivity
If a single laser beam is used for processing, then the system is easier to control, but processing speed is limited due to sequential single-point melting
Solution Approach 1:
The processing task is segmented into multiple parallel operations using multiple laser beams. Each beam processes a different location simultaneously, transforming sequential single-point melting into parallel multi-point melting, thereby dramatically increasing processing speed while maintaining control through independent beam regulation.
Solution Approach 2:
Multiple laser beams enable continuous processing across multiple locations simultaneously, eliminating the idle time between sequential single-point operations. The system maintains continuous useful action by processing different regions in parallel, significantly boosting productivity.
3Adaptability or versatility
If separate optical trains are used for each laser beam, then independent beam control is achieved, but the system becomes bulky, heavy, and expensive
Solution Approach 1:
Multiple separate optical trains are merged into a single integrated optical system. The patent combines beam combining optics that allow multiple beams to share common optical components such as scanners and focus lenses, reducing system bulk and weight while maintaining independent control capability through optical switching and beam combining techniques.
Solution Approach 2:
The optical system is designed with multi-functionality where a single optical train serves multiple beams. Common components like scanners, focus lenses, and detectors are shared across all beams, eliminating redundancy and reducing system complexity, size, and cost while preserving adaptability.
4Extent of automation
If conventional laser sources are used without adaptive control, then the system is simpler, but real-time modification of beam characteristics based on sensing data is not possible
Solution Approach 1:
The system incorporates sensors that detect material properties and processing conditions in real-time, feeding this information back to the beam control system. This feedback loop enables automatic adjustment of beam characteristics such as power, focus, and position based on actual processing conditions, achieving real-time adaptive control that improves quality and productivity.
Solution Approach 2:
The laser beam characteristics are made dynamic and adjustable in real-time rather than fixed. The system can rapidly modify beam power, focal position, and spatial distribution during processing based on feedback from sensors, enabling adaptive control that responds to changing material properties and processing conditions.
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 enhances the quality and productivity of LAM by improving micro-structure control, reducing residual stress, and increasing processing speed through precise control of laser beams, resulting in improved surface finish and uniformity.
Implementation Method 1
a laser is used to heat the metal powder in a desired pattern so that it melts
Implementation Method 2
adaptive multi-beam shaping
Implementation Method 3
beam steering characteristics
Implementation Method 4
in situ sensing systems for characterization of both stock material in front of the processing beam and melted and consolidated into metal materials
Data Source
AI summary
A system that uses a scalable array of individually controllable laser beams that are generated by a fiber array system to process materials into an object. The adaptive control of individual beams may include beam power, focal spot width, centroid position, scanning orientation, amplitude and frequency, piston phase and polarization states of individual beams. Laser beam arrays may be arranged in a two dimensional cluster and configured to provide a pre-defined spatiotemporal laser power density distribution, or may be arranged linearly and configured to provide oscillating focal spots along a wide processing line. These systems may also have a set of material sensors that gather information on a material and environment immediately before, during, and immediately after processing, or a set of thermal management modules that pre-heat and post-heat material to control thermal gradient, or both.