Additive Manufacturing Scan Sequence for Bottom Surface Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Layer-wise additive manufacturing methods face challenges in achieving high-quality surfaces oriented parallel to layers due to temperature differences and stress caused by varying heat conductivity, particularly in bottom and top surface regions, leading to inhomogeneous density and imperfect melting.
Innovation Solution
A method and device that modify the layer-wise additive manufacturing process by prioritizing the scanning of bottom and top surface regions with energetic radiation earlier than the rest of the object cross-section, using a control dataset generated from modified layer datasets, to minimize the impact of splashes, vapors, and smoke, and optimize energy input for improved surface quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the object cross-section is scanned sequentially from one side to the other, then the manufacturing process is simple to control, but temperature differences and stress occur due to varying heat conductivity leading to deteriorated surface quality
Solution Approach 1:
The object cross-section is divided into multiple regions (bottom surface region, top surface region, and intermediate regions) with different scanning priorities. This segmentation allows differential treatment of areas with varying thermal characteristics, addressing the heat conductivity variation problem while maintaining manageable control complexity through systematic region-based processing.
Solution Approach 2:
The bottom surface region and top surface region are scanned preliminarily before the intermediate regions. This preliminary action ensures that areas most susceptible to temperature differences and stress (where unsolidified material interfaces with solidified layers) receive energy input first, preventing thermal gradients and improving surface quality before the bulk of the material is processed.
2Manufacturing precision
If energy input is increased to improve solidification quality, then surface quality improves, but temperature differences increase leading to more stress and inhomogeneous density
Solution Approach 1:
Different energy input strategies are applied to different regions of the object cross-section. The bottom and top surface regions receive prioritized energy input to ensure proper solidification where thermal gradients are most problematic, while intermediate regions are processed subsequently. This local differentiation achieves uniform solidification quality without causing excessive temperature differences.
Solution Approach 2:
The scanning sequence parameter is changed to process bottom and top surface regions first, then intermediate regions. This parameter modification optimizes the energy distribution pattern, ensuring that critical surfaces solidify under controlled conditions before the bulk material is processed, thereby achieving uniform temperature distribution and homogeneous density.
3Manufacturing precision
If the scanning of bottom and top surface regions is delayed until after intermediate regions, then the manufacturing process follows a simple sequential pattern, but splashes, vapors, and smoke from intermediate regions contaminate the surface regions
Solution Approach 1:
The bottom surface region and top surface region are scanned preliminarily before the intermediate regions to prevent contamination from splashes, vapors, and smoke. By establishing these critical surfaces first, the method ensures their cleanliness and quality are not compromised by subsequent processing of the bulk material, while the overall manufacturing efficiency is maintained through systematic sequential processing.
Solution Approach 2:
The method applies preliminary anti-action by protecting the bottom and top surface regions from contamination before the contaminating processes (splashes, vapors, smoke generation during intermediate region processing) occur. This preventive approach ensures surface cleanliness without requiring additional protective measures or rework.
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
The approach results in improved surface quality by reducing inhomogeneities and temperature inconsistencies, ensuring a more homogeneous solidification process and enhanced object quality, particularly for bottom and top surface regions.
Implementation Method 1
solidification of the building material by means of a supply of radiation to positions in a layer that correspond to the cross-section of the object in this layer
Implementation Method 2
supply of heat energy to the building material by irradiating the same with electromagnetic radiation or particle radiation (e.g. laser sintering (SLS or DMLS) or laser melting)
Implementation Method 3
the solidification can be effected by means of a supply of heat energy to the building material by irradiating the same with electromagnetic radiation or particle radiation
Implementation Method 4
solidification of the building material by means of a supply of radiation
Data Source
AI summary
A method for providing control data for a generative layer construction device includes accessing layer data records that have data models of buildup material layers to be selectively solidified, where a base surface region of an object cross section exists in at least one layer data record, where in at least one of p layers below the base surface region, no solidification of buildup material is specified. The method further includes changing the layer data record such that a temporal sequence for scanning the associated object cross section with energy radiation is specified such that at least one portion of the base surface region is scanned before all other parts of the object cross section; and a third step, where the changed layer data record is provided for the generation of a control data record for the device.