Electron Beam Patterning for Powder Bed Additive Manufacturing
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Solution Overview
Problem
Semiconductor lasers used in additive manufacturing systems face limitations in achieving high enough intensity to effectively bond melted powder to the base due to lower brightness compared to solid state lasers, leading to potential surface tension issues and incomplete bonding.
Innovation Solution
The proposed optical system employs polarization combining techniques to increase the intensity of semiconductor laser light by up to twice the original intensity, achieving near 100% transmission efficiency, thereby overcoming the brightness limitations and ensuring effective bonding in additive manufacturing processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If semiconductor lasers are used in additive manufacturing systems, then cost is reduced compared to solid state lasers, but intensity and brightness are insufficient to effectively bond melted powder to the base
Solution Approach 1:
The patent combines multiple semiconductor laser beams into a single high-intensity beam using beam combining technology. This allows the system to achieve the high intensity levels (greater than 370 kW/cm²) required for effective powder bonding while maintaining the cost advantages of semiconductor lasers, thus resolving the contradiction between cost and intensity.
2Manufacturing precision
If semiconductor lasers are used to achieve high resolution imaging, then feature size requirements can be met, but the distance between the build platform and powder distribution mechanism must be reduced
Solution Approach 1:
The patent uses optical zoom lenses and image relay systems to achieve high resolution imaging at extended distances. By manipulating the optical path and using intermediate imaging stages, the system maintains 7 um point imaging FWHM resolution while enabling the build platform to be positioned at distances greater than 250 mm from the powder distribution mechanism, thus resolving the contradiction between manufacturing precision and working distance.
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 processing of a wider range of materials with improved bonding quality and reduced energy losses, enhancing the efficiency and effectiveness of semiconductor laser-based additive manufacturing systems.
Implementation Method 1
The optical system may include a first set of optics configured to receive a first beam of light having a first polarization state and a second set of optics configured to receive a second beam of light having a second polarization state. The optical system may further include a polarization combining beam splitter configured to combine the first beam of light and the second beam of light into a single beam of light having an increased intensity
Data Source
AI summary
A method and an apparatus involve applying a pattern on an addressable patternable cathode unit. The cathode unit is stimulated to emit an electron beam pattern. A patterned image in the electron beam pattern is positioned to a desired position such directly to as a powder bed for additive manufacturing or to an electron beam addressed light valve for controlling spatial patterns on an optical signal for powder bed manufacturing.