Polygon Scanner Beam Sequencing for Low-Stress Additive Fusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In additive manufacturing, existing energy delivery systems for fusing materials often require high power and can cause thermal stress, which affects the quality of the final product and is inefficient in terms of energy usage.
Innovation Solution
The proposed solution involves an additive manufacturing apparatus with a dual light beam system, where a polygon mirror scanner and a galvo mirror scanner work in conjunction to deliver energy to the material, allowing for pre-heating and controlled cooling, reducing the power needed to fuse the material and minimizing thermal stress by using a first light beam to raise the material's temperature below its fusion point and a second light beam to further raise it above the fusion point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a single high-power light beam is used to fuse the material, then the fusion process is achieved, but thermal stress increases and energy efficiency decreases
Solution Approach 1:
The single high-power light beam is divided into two separate light beams with different power levels. The first light beam operates at a lower power level to preheat the material, while the second light beam operates at a higher power level to complete the fusion process. This segmentation of the energy delivery system allows for more controlled heating and reduces thermal stress on the material.
Solution Approach 2:
The first light beam performs preliminary heating of the material to a temperature below the fusion point before the second light beam is activated. This preliminary action prepares the material by raising its temperature in a controlled manner, reducing the temperature differential and thermal stress that would occur with direct high-power heating, thereby enabling the second light beam to complete fusion more efficiently.
2Power
If a single high-power light beam is used to fuse the material, then the fusion process is achieved, but energy efficiency decreases
Solution Approach 1:
The energy delivery is segmented into two phases using two separate light beams. The first light beam delivers lower power for extended preheating, while the second light beam delivers higher power for a shorter duration to complete fusion. This segmentation optimizes energy usage by matching power levels to the material's heating stages, improving overall energy efficiency compared to using a single high-power beam throughout the entire process.
Solution Approach 2:
The first light beam performs preliminary heating to raise the material temperature below the fusion point, preparing the material for efficient fusion. This preliminary action reduces the total energy required for the subsequent fusion step by the second light beam, as the material is already closer to the fusion temperature, thereby improving overall energy efficiency.
3Device complexity
If a single light beam is used, then the system is simpler, but control over the cooling process is less precise
Solution Approach 1:
The system is segmented into two independent light beam delivery paths, each with its own scanner (polygon mirror scanner for the first light beam, galvo mirror scanner for the second light beam). This segmentation enables independent control of each beam's parameters including power, duration, and scanning pattern, providing precise control over the heating and cooling processes despite the increased device complexity.
Solution Approach 2:
The system employs dynamic control of two light beams with different characteristics. The first light beam can be scanned in specific patterns to create controlled thermal gradients, while the second light beam provides focused high-power input. The independent scanning mechanisms allow dynamic adjustment of energy distribution in space and time, enabling precise control over material heating and subsequent cooling rates for improved manufacturing precision.
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 reduces the power required for fusion, enhances part quality by minimizing thermal stress, and allows for more precise control over the cooling process, resulting in improved additive manufacturing outcomes.
Implementation Method 1
cause the first light beam to apply sufficient heat to raise a temperature of the feed material from a first temperature to a second temperature that is below a third temperature (TF) at which the feed material fuses
Implementation Method 2
cause the second light beam to apply sufficient heat to the feed material to further raise a temperature of the feed material above a temperature (TF) at which the feed material fuses
Implementation Method 3
The polygon mirror scanner is configured to receive the first light beam and reflect the first light beam towards the platform. Rotation of the first polygon mirror causes the light beam to move in a first direction along a path on a layer of feed material on the platform
Implementation Method 4
The galvo mirror scanner system is configured to receive the second light beam and reflect the second light beam toward the platform
Data Source
AI summary
An additive manufacturing apparatus includes a platform, a dispenser configured to deliver a plurality of successive layers of feed material onto the platform, at least one light source configured to generate a first light beam and a second light beam, a polygon mirror scanner, an actuator, and a galvo mirror scanner. The polygon mirror scanner is configured to receive the first light beam and reflect the first light beam towards the platform. Rotation of the first polygon mirror causes the light beam to move in a first direction along a path on a layer of feed material on the platform. The actuator is configured to cause the path to move along a second direction at a non-zero angle relative to the first direction. The galvo mirror scanner system is configured to receive the second light beam and reflect the second light beam toward the platform.