Powder Bed Heating With Ring-Shaped Beam for Uniform 3D Printing
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Solution Overview
Problem
Existing processing machines for three-dimensional component production by selective laser melting face challenges in achieving a homogeneous temperature distribution in the powder bed due to geometric constraints and heat loss, leading to inhomogeneous heat balance and temperature gradients, especially when heating from below with a large radiating surface support.
Innovation Solution
The use of a heating device with a ring-shaped beam profile, generated by a beam shaping optical unit, to supply heat from above, combined with additional heating from below, helps to homogenize the temperature distribution. This involves aligning the heating beam axis stationary over the processing field and using a beam shaping optical unit to adjust the intensity distribution, potentially with axicons, to create a rotationally symmetric ring-shaped beam profile that can vary in intensity, ensuring even heating across the powder bed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If heating is performed from below using a large radiating surface support, then the heating area is increased, but temperature gradients and inhomogeneous temperature distribution occur
Solution Approach 1:
The heating system is segmented into multiple independent heating zones (first heating zone from below, second heating zone from above) that can be controlled separately. This allows different regions of the powder bed to be heated independently, enabling compensation for heat losses at edges and corners while maintaining uniform temperature distribution across the entire heating area.
Solution Approach 2:
Different heating intensities and methods are applied to different locations: the first heating zone provides general heating from below, while the second heating zone provides targeted heating from above, particularly at edges and corners where heat losses are higher. This local differentiation of heating quality compensates for geometric heat losses and achieves uniform temperature distribution.
2Productivity
If the powder bed height increases during layer-by-layer construction, then the component is built up, but heat balance stability deteriorates due to increased heat losses
Solution Approach 1:
Both heating zones operate continuously throughout the layer-by-layer construction process. The first heating zone maintains baseline heating from below, while the second heating zone continuously compensates for heat losses from above. This continuous dual-directional heating ensures stable heat balance even as the powder bed height increases and surface area for heat loss grows.
Solution Approach 2:
The heating system dynamically adjusts heating parameters (intensity, distribution) based on the changing powder bed height and heat loss conditions. As construction progresses and the powder bed rises, the heating zones adapt their output to maintain optimal temperature distribution, compensating for the increasing heat losses associated with greater height and surface area.
3Device complexity
If a conventional beam profile is used for heating from above, then the setup is simple, but temperature homogeneity in the processing field is insufficient
Solution Approach 1:
The beam profile of the heating radiation is transformed from a conventional Gaussian distribution to a ring-shaped profile using beam shaping optical elements. This parameter change in the radiation intensity distribution allows the second heating zone to target edges and corners more effectively, compensating for geometric heat losses and achieving uniform temperature distribution across the processing field while maintaining relatively simple device architecture.
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 effectively reduces temperature gradients and achieves a more homogeneous temperature distribution in the powder bed, minimizing heat losses and maintaining a stable heat balance during the layer-by-layer construction process, even as the powder bed height increases.
Implementation Method 1
a heating device (18) which has a heating radiation source (19) for generating a heating beam (20) for heating the powder (3) from above
Implementation Method 2
a beam shaping optical unit (22) configured to convert a first beam profile (S1) of the heating beam (20) into a second beam profile (S2), e.g., a ring-shaped beam profile
Implementation Method 3
producing machines and methods for producing a three-dimensional component (2) layer by layer by irradiating a powder (3) with a processing beam (6), in particular by a laser beam
Data Source
AI summary
The disclosure relates to processing machines and methods for producing three-dimensional components by irradiating powder with a processing beam, the machines including a container with a moveable support for the powder, as well as an irradiating device with a scanner device for aligning the processing beam on a processing field at an opening of the container. The irradiating device includes a heating device that includes a heating radiation source for generating a heating beam for heating the powder from above and including a beam shaping optical unit configured to convert a first beam profile of the heating beam into a second beam profile, e.g., a ring-shaped beam profile, of the heating beam.