Large-Scale Powder Bed Build Unit With Laminar Gasflow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional additive manufacturing systems face challenges in scaling up to larger formats, leading to issues with uniform layer-wise powder distribution, effective gas plume management, and control of laser energy density, resulting in defects and inferior surface finishes on large parts.
Innovation Solution
A large-scale additive manufacturing apparatus with a build unit that includes a powder dispenser, recoater blade, and irradiation emission directing device, capable of moving in three dimensions and rotating in the x-y plane, along with a laminar gasflow zone for efficient gas management, and a selective recoater with multiple gates for precise powder control, to maintain a reduced oxygen environment and ensure uniform powder distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional additive manufacturing systems are scaled up to larger formats, then build size increases, but uniform layer-wise powder distribution deteriorates
Solution Approach 1:
The powder dispenser is divided into multiple independently controllable powder gates (first gate, second gate, etc.) that can selectively deposit powder in different regions. This segmentation allows precise control over powder distribution across large build areas, maintaining uniformity even as build size increases.
Solution Approach 2:
The system applies different powder deposition strategies to different regions of the build area. The multiple powder gates enable localized powder delivery with varying rates and patterns, ensuring optimal powder distribution uniformity in each local region while accommodating the overall large build size.
2Volume of moving object
If build size increases in conventional systems, then larger parts can be produced, but gas plume management effectiveness deteriorates
Solution Approach 1:
The gasflow device introduces a laminar gas flow field that creates a controlled atmospheric environment above the build area. By establishing this dimensional gas flow layer, the system effectively manages laser-generated plumes and fumes across large build volumes, preventing harmful gas accumulation even as build size increases.
Solution Approach 2:
The gasflow device creates a controlled gas environment (likely inert or controlled atmosphere) over the build area, which helps manage laser-induced fumes and plumes. This controlled atmospheric layer effectively contains and directs harmful gases away from the build region, maintaining effective gas plume management across large build volumes.
3Volume of moving object
If build size increases in conventional systems, then larger parts can be manufactured, but control of laser energy density deteriorates
Solution Approach 1:
The irradiation emission directing device is mounted on a build unit that can move in three dimensions and rotate in the x-y plane. This dynamic positioning capability allows the laser to maintain optimal energy density control across large build areas by adjusting its position and orientation, ensuring consistent manufacturing precision regardless of build size.
Solution Approach 2:
The build unit integrates multiple functions: powder dispensing, recoating, and laser irradiation, all within a single movable and rotatable unit. This multi-functionality allows coordinated control of powder delivery and laser energy application, maintaining precise laser energy density control across the entire large build volume through unified system operation.
4Device complexity
If conventional systems use simple powder dispensing, then device complexity is low, but surface finish quality deteriorates
Solution Approach 1:
The powder dispenser uses multiple independently controlled gates instead of a single simple dispensing mechanism. This segmented approach, while increasing device complexity, enables precise control over powder deposition in different regions, resulting in significantly improved surface finish quality on large parts.
Solution Approach 2:
The recoater blade serves as an intermediary between powder deposition and laser processing. It spreads and levels the powder deposited by the multiple gates, ensuring uniform powder distribution and smooth surface preparation before laser irradiation, thereby achieving high surface finish quality.
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
Enables the production of high-precision, large-scale additively manufactured objects with improved surface finish and reduced defects by maintaining uniform powder distribution and efficient gas flow, allowing for larger build sizes with precise control over powder deposition and laser energy density.
Implementation Method 1
a gasflow device adapted to provide substantially laminar gas flow over a work surface
Implementation Method 2
an irradiation emission directing device adapted to direct laser irradiation or e-beam irradiation
Implementation Method 3
the energy beam sinters or melts a cross sectional layer of the object being built
Implementation Method 4
sintering entails fusing (agglomerating) particles of a powder at a temperature below the melting point of the powder material
Data Source
AI summary
The present disclosure generally relates to additive manufacturing systems and methods on a large-scale format. One aspect involves a build unit that can be moved around in three dimensions by a positioning system, building separate portions of a large object. The build unit has an energy directing device that directs, e.g., laser or e-beam irradiation onto a powder layer. In the case of laser irradiation, the build volume may have a gasflow device that provides laminar gas flow to a laminar flow zone above the layer of powder. This allows for efficient removal of the smoke, condensates, and other impurities produced by irradiating the powder (the “gas plume”) without excessively disturbing the powder layer. The build unit may also have a recoater that allows it to selectively deposit particular quantities of powder in specific locations over a work surface to build large, high quality, high precision objects.