Multi-Laser Additive Manufacturing for Controlled Melt and Cooling
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Solution Overview
Problem
Conventional additive manufacturing systems using single laser configurations for Selective Laser Sintering (SLS) and Selective Laser Melting (SLM) face challenges such as material overheating, vaporization, and uncontrolled cooling, leading to unpredictable material properties and defects in 3D parts.
Innovation Solution
The proposed solution involves the use of a plurality of laser assemblies to selectively heat the working material in a stepped increase of temperatures, ensuring precise control over the heating and cooling processes to prevent overheating and vaporization, thereby achieving consistent and predictable material properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single laser is used to quickly heat the working material above the melting point to fuse particles, then the manufacturing speed is improved, but the material overheating and vaporization occurs causing unpredictable material properties
Solution Approach 1:
The single laser heating process is segmented into multiple laser beams (first, second, third lasers) that heat the material in sequential steps to different peak temperatures. This segmentation allows controlled heating through melting point without excessive temperature rise, preventing vaporization while maintaining manufacturing efficiency.
Solution Approach 2:
The invention changes the temperature parameters by using multiple lasers with different power levels to create stepped heating stages. The first laser heats to a first peak temperature, the second laser heats to a second peak temperature higher than the first, and the third laser heats to a third peak temperature above the melting point. This parameter control prevents material vaporization while ensuring complete fusion.
2Strength
If a single laser heats material to temperatures far exceeding melting point and boiling point, then the fusion is achieved quickly, but material vaporization and spatter occur leading to material loss
Solution Approach 1:
The first and second lasers perform preliminary heating actions to bring the material to progressively higher temperatures before the third laser completes the fusion process. This preliminary action ensures the material is properly prepared for fusion without requiring excessive temperature that would cause vaporization and material loss.
3Device complexity
If conventional systems allow material to cool without controlled cooling, then the process is simple, but residual stress and cracks are formed in the 3D part
Solution Approach 1:
The system incorporates feedback control through sensors that monitor the material temperature and cooling process. This feedback enables controlled cooling rates that prevent residual stress and cracking while maintaining process simplicity through automated control.
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 allows for the production of 3D parts with consistent, predictable, and reproducible material properties, reducing defects and ensuring high-quality manufacturing outcomes.
Implementation Method 1
a laser to heat and sinter a source material that is often in powdered form
Implementation Method 2
Selective Laser Melting (SLM) which generally applies similar principles as SLS to create a 3D part utilizing a laser to selectively melt a working material
Implementation Method 3
a single laser configuration lets the material cool without any controlled cooling leading to residual stress
Data Source
AI summary
An additive manufacturing method may provide energy beams to gradually heat the working material, to fuse the working material, and to gradually cool the working material in a controlled method. The energy beams may be provided by a plurality of laser assemblies. The energy beams may produce an irradiation profile including a first portion that heats the working material to a first peak temperature lower than a melting point of the working material, a second portion that heats the working material to a second peak temperature being higher than the first peak temperature and lower than the melting point of the working material, a third portion that heats the working material to a third peak temperature being higher than the melting point of the working material and lower than a boiling point of the working material, and a fourth portion that heats the working material to a fourth peak temperature being less than the third peak temperature. The irradiation profile may be moved along the working path such that a portion of the working material along the working path sequentially encounters the first portion, the second portion, the third portion, and the fourth portion.