Additive Manufacturing Scanning Sequence to Suppress Projections
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Solution Overview
Problem
The powder lamination melting method for additive manufacturing often results in unintentional projections during the formation of three-dimensional shaped objects due to solidified parts rising, which can interfere with the squeegeeing blade and reduce forming accuracy, and existing solutions complicate the manufacturing process by adding cutting mechanisms.
Innovation Solution
A method where the energy beam is scanned to alternate areas within the powder layer, ensuring that the irradiation starting points for forming upper and lower solidified layers do not overlap, thereby preventing the accumulation of bumps and projections by differentiating the widths of contour and inner-solid areas among layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the energy beam is irradiated to the powder layer to selectively melt it, then the three-dimensional shaped object is formed by laminating solidified layers, but unintentional projections are generated due to solidified parts rising, which reduces forming accuracy
Solution Approach 1:
The patent applies preliminary action by scanning and irradiating the contour area (outer perimeter) of the powder layer before irradiating the inner-solid area. This preliminary contour scanning prevents the solidified parts from rising and forming projections during the subsequent inner area melting process, thereby eliminating the harmful projections while maintaining forming accuracy
Solution Approach 2:
The patent segments the powder layer irradiation process into two distinct areas: the contour area (outer perimeter region) and the inner-solid area (central region). By dividing the irradiation process into these two segments and executing them in sequence, the patent prevents projection formation at the contour while efficiently melting the inner area, thus resolving the contradiction between forming accuracy and projection generation
2Productivity
If a cutting mechanism is provided to cut the upper surface of raised solidified portions, then the additive manufacturing process can continue, but the apparatus becomes complicated and the manufacturing time is prolonged
Solution Approach 1:
The patent extracts and eliminates the source of projections by modifying the energy beam scanning sequence - specifically by performing contour area scanning before inner-solid area scanning. This extraction of the problematic projection-formation mechanism from the process eliminates the need for additional cutting mechanisms, thereby reducing apparatus complexity while maintaining productivity
Solution Approach 2:
The patent applies self-service by designing the irradiation sequence to automatically prevent projection formation during the manufacturing process itself. The contour-first scanning method inherently prevents solidified part rising, making the process self-correcting and eliminating the need for separate correction mechanisms, thus maintaining high productivity without increasing device complexity
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 suppresses the formation of large projections, preventing interference with the squeegee and improving the accuracy of the three-dimensional shaped objects by ensuring that the energy beam starting points do not overlap, thus maintaining a stable manufacturing process.
Implementation Method 1
a second step of scanning and irradiating an energy beam to the powder layer to melt and then solidifying the powder layer to form a solidified layer
Implementation Method 2
a step of selectively melting a part of the powder layer by irradiating a laser beam
Data Source
AI summary
A manufacturing method of a three-dimensional shaped object includes a first step of depositing powder to form a powder layer, and a second step of scanning and irradiating an energy beam to the powder layer to melt and then solidifying the powder layer to form a solidified layer. The energy beam is irradiated to the powder layer corresponding to a contour area and an inner-solid area inside of the contour area. The first and second steps are alternately and repeatedly executed. The energy beam is scanned such that an irradiation starting point of the energy beam for forming an upper solidified layer does not overlap with an irradiation starting point of the energy beam for forming a lower solidified layer in a view from a lamination direction.