Additive Layer Manufacturing With Variable Atmosphere and Beam Spot
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Solution Overview
Problem
Existing additive layer manufacturing methods, such as selective laser melting and direct material deposition, face challenges in efficiently and cost-effectively changing material properties between different parts of a three-dimensional object, making it difficult to produce graduated or complex objects with varying characteristics.
Innovation Solution
The method involves controlling the gas atmosphere, beam spot size, and temperature during the additive layer manufacturing process to selectively change the material properties of different layers, allowing for the use of different gas atmospheres, beam spot sizes, and temperatures for various subsets of layers, enabling the creation of objects with specific material properties without additional work steps or significant cost increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If material is changed between different layers in additive layer manufacturing, then different material characteristics can be achieved in different parts of the object, but the process becomes time-consuming, difficult to implement and costly
Solution Approach 1:
The patent applies parameter changes by varying the oxygen concentration in the gas atmosphere during different stages of layer irradiation. By controlling the oxygen level parameter, the material properties (such as hardness, strength, or surface characteristics) of different layers can be selectively modified without physically changing the base material or adding complex material handling systems, thus avoiding time loss and additional costs.
Solution Approach 2:
The patent implements local quality by creating spatially differentiated material properties within the same object through localized exposure to controlled oxygen atmospheres during irradiation. Different regions of the object receive different gas compositions tailored to achieve specific local characteristics, enabling graduated objects with varying properties in different parts while maintaining a uniform manufacturing process.
2Adaptability or versatility
If material is changed between different layers in additive layer manufacturing, then different material characteristics can be achieved in different parts of the object, but the implementation becomes difficult and costs increase
Solution Approach 1:
The patent simplifies manufacturing by changing only the gas atmosphere parameter (oxygen concentration) rather than physically changing materials. This approach maintains process simplicity while achieving material characteristics variation, as the gas composition can be adjusted through standard atmospheric control systems already present in additive manufacturing equipment, avoiding complex material changeover mechanisms.
Solution Approach 2:
The patent achieves local quality differentiation through controlled oxygen exposure during irradiation of specific layers or regions. This method is easier to implement than material changes because it uses the existing laser or electron beam irradiation process combined with gas atmosphere control, eliminating the need for additional material handling, storage, and changeover equipment.
3Stability of the object's composition
If a tightly controlled constant inert gas atmosphere is maintained to avoid reactions between layers and surrounding gases, then layer stability is improved, but the ability to modify material properties in different parts of the object is limited
Solution Approach 1:
The patent introduces dynamics by transitioning from a static constant inert gas atmosphere to a dynamic controllable atmosphere that can vary oxygen concentration as needed. The gas composition is adjusted in real-time during the manufacturing process, allowing the system to maintain stability when needed (inert atmosphere) and enable material property modification when required (controlled oxygen exposure), thus resolving the contradiction between stability and adaptability.
Solution Approach 2:
The patent applies segmentation by dividing the manufacturing process into distinct stages with different gas atmosphere conditions. Certain layers are irradiated under inert gas to maintain composition stability, while other layers are irradiated under controlled oxygen-containing atmospheres to achieve desired material properties. This segmented approach allows both stability and versatility to be achieved in different parts of the manufacturing process.
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 rapid and cost-effective production of three-dimensional objects with varied material properties, enabling the creation of complex structures with functional surfaces and gradients in material properties, improving manufacturing efficiency and reducing production costs.
Implementation Method 1
irradiating each layer with a laser or particle beam prior to providing the subsequent layer
Implementation Method 2
the material of the respective layer is melted or sintered locally in the irradiated portions
Implementation Method 3
the material of the respective layer is melted or sintered locally in the irradiated portions
Implementation Method 4
at least one of the pressure and composition of the gas atmosphere inside the chamber is changed in the course of the process such that the gas atmosphere in which one or more of the layers are irradiated is different from the gas atmosphere in which others of the layers are irradiated
Implementation Method 5
provided that low pressures can be present inside the chamber, the irradiation may be effected by means of an electron beam
Data Source
Figure 1~2
Figure 3
AI summary
The present invention relates to a method of manufacturing a three-dimensional object by additive layer manufacturing and to a corresponding apparatus. The method comprises successively providing a plurality of layers (20a, 20b, 20c) of material in powder form, one on top of the other, on a support means (7) inside a chamber (3), and irradiating each layer with a laser beam (13) or particle beam prior to providing the subsequent layer. A gas atmosphere having a controlled pressure and composition is maintained inside the chamber (3) at least during each of the irradiation steps. At least one of the pressure and the composition of the gas atmosphere inside the chamber (3) is controlled such that at least two different gas atmospheres having different predetermined pressures and/or compositions are present inside the chamber (3) during the irradiation of different ones of the layers, the beam spot size of the laser beam (13) and the particle beam, respectively, on the layers during irradiation thereof is controlled such that at least two different beam spot sizes are utilized during the irradiation of different ones of the layers, and/or the temperature of the gas atmosphere inside the chamber (3) and/or of the layer being irradiated is controlled such that at least two different temperatures of the gas atmosphere and/or of the layer being irradiated are present during the irradiation of different ones of the layers.