Movable Heat Shield Structure for Cleaner Electron Beam Melting
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Solution Overview
Problem
Current heat shields in additive manufacturing processes leak metallization and heat, which can contaminate the vacuum chamber and affect the quality of the three-dimensional articles being formed.
Innovation Solution
A movable hollow construction and shielding means are introduced, which can be positioned to minimize heat radiation and metallization leakage by being in contact with the powder table or lowered into the build tank, depending on the stage of the powder distribution and fusion process, effectively acting as a barrier to prevent contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a heat shield is used to shield the vacuum chamber from heat radiation and metallization, then the vacuum chamber is protected from contamination, but the heat shield leaks heat and metallization
Solution Approach 1:
The heat shield is divided into multiple segments including a first flap and a second flap that can move independently. This segmentation allows each flap to be positioned optimally for different operational phases (powder distribution vs. electron beam melting), reducing overall heat and metallization leakage while maintaining shielding effectiveness.
Solution Approach 2:
The heat shield flaps are designed to be movable rather than fixed, allowing them to tilt forward or backward based on the operational phase. During powder distribution, the flaps tilt forward to allow powder passage; during electron beam melting, they tilt backward to maximize shielding. This dynamic adjustment optimizes both shielding effectiveness and operational functionality.
2Ease of operation
If the heat shield flaps are tilted forward to allow powder distributor passage, then the powder distributor can move freely, but heat and metallization leakage increases
Solution Approach 1:
The heat shield flaps operate periodically, tilting forward during powder distribution phases and tilting backward during electron beam melting phases. This periodic action allows the system to optimize for powder distributor movement during distribution phases while minimizing heat and metallization leakage during melting phases.
Solution Approach 2:
The flaps are designed with dynamic positioning capability, allowing them to change orientation based on operational requirements. The forward tilt facilitates powder distributor passage, while the backward tilt reduces leakage, with transitions between these states timed to match operational phases.
3Reliability
If the hollow construction is made larger to improve shielding, then shielding effectiveness improves, but the apparatus complexity and space requirements increase
Solution Approach 1:
Rather than creating one large complex shield, the system uses multiple smaller flap segments that can be independently positioned. These segmented flaps collectively provide effective shielding during melting operations while allowing simplified structure during powder distribution, reducing overall apparatus complexity.
Solution Approach 2:
The movable flap design allows the heat shield to achieve effective shielding coverage only when needed during electron beam melting operations. During powder distribution, the flaps tilt forward to clear the path, reducing the effective shielding volume and simplifying the operational space requirements.
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 configuration significantly reduces metallization and heat radiation leakage, enhancing the quality of the three-dimensional articles by maintaining a cleaner vacuum environment and improving the additive manufacturing process.
Implementation Method 1
a high energy beam for delivering energy to the powder whereby fusion of the powder takes place
Implementation Method 2
fusion of the powder takes place
Implementation Method 3
The heat shield is arranged for shielding the surrounding vacuum chamber from metallization and heat radiation
Data Source
Figure 1a~1e
Figure 1b~1g
Figure 2
AI summary
The present invention relates to an apparatus for forming a three-dimensional article through successively depositing individual layers of powder material that are fused together so as to form the article, the apparatus comprising an electron beam source emanating an electron beam for fusing the powder material in a build tank, a hollow construction having an upper opening and a lower opening, means for moving the hollow construction between a first position and a second position, a synchronising unit for synchronising the movement of a powder distributor for applying the individual layers of powder material on the work table with the movement of the hollow construction so that the hollow metal construction is at the first position when fusing and/or heating the powder layer and at the second position when the powder distributor is distributing the powder material for forming the individual powder layers.