3D Printing Scan Path Control for Region-Specific Beam Heating

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Solution Overview

Problem

Existing additive manufacturing methods face challenges in efficiently adapting energy input for layer-wise solidification of building materials, leading to stress and reduced quality due to temperature differences between solidified and unsolidified regions, particularly in metal powders.

Innovation Solution

A method that defines a scanning sequence for electromagnetic or particle radiation to solidify building materials across different regions (sandwiched, down-facing, and up-facing) with continuous scan lines and adjusted beam parameters at interfaces, reducing stress and improving precision by minimizing temperature differences and energy input adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the energy input is adapted to the heat conductivity of surrounding material (solidified vs. unsolidified powder), then the quality and stress reduction is improved, but the computational complexity and process time increases due to voxel analysis for each position

Engineering Contradiction:
ImprovequalityVSAvoidcomputational complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The build chamber is divided into distinct regions (sandwiched, down-facing, up-facing) based on their thermal characteristics and support conditions. This segmentation allows for region-specific energy input strategies without requiring complex voxel-by-voxel analysis, simplifying the computational process while maintaining quality control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different energy input parameters are applied to different regions: sandwiched regions receive higher energy input due to good thermal contact with solidified material, while down-facing regions receive reduced energy input due to poor thermal contact with unsolidified powder. This local adaptation of energy input maintains manufacturing precision without complex computations.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the beam parameters are continuously adjusted at each position based on surrounding heat conductivity, then the stress reduction and quality improvement is enhanced, but the manufacturing time increases due to frequent parameter changes

Engineering Contradiction:
Improvestress reductionVSAvoidmanufacturing time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

Instead of continuous parameter adjustment, the manufacturing space is segmented into discrete regions with characteristic thermal properties. Each region is assigned specific beam parameters, allowing for stress reduction through region-appropriate energy input without the time penalty of continuous adjustment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The beam parameters are changed periodically at region boundaries rather than continuously at each position. This periodic action maintains the stress reduction benefits of adaptive energy input while significantly reducing the time required for parameter adjustments during manufacturing.

Inventive Principle:
Principle #19Periodic action

3Use of energy by moving object

If separate scan lines are used for different regions (sandwiched, down-facing, up-facing), then the energy input can be optimized for each region, but the scanning time increases due to interruptions and repositioning

Engineering Contradiction:
Improveenergy input optimizationVSAvoidscanning time
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

Scan lines from different regions are merged into continuous paths that traverse multiple regions without interruption. The beam parameter changes occur smoothly at region boundaries during continuous scanning, eliminating repositioning time while maintaining region-specific energy input optimization.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The scanning process maintains continuous useful action by avoiding beam interruptions and repositioning between regions. Continuous scan lines pass through multiple regions with parameters adjusted in real-time at boundaries, eliminating idle time and maintaining manufacturing efficiency.

Inventive Principle:
Principle #20Continuity of useful action

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 reduces stress and improves manufacturing precision by maintaining consistent energy input across regions, minimizing temperature differences and reducing the time required for solidification, resulting in higher quality three-dimensional objects.

Implementation Method 1

thermal energy is introduced into the material by irradiating the same with a laser beam

Methodology Applied
Scientific EffectElectromagnetic radiation heating: Electromagnetic Induction

Implementation Method 2

the amount of thermal energy is adjusted at least in a sub-region of a layer dependent on the duration of the previous solidification step

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 3

a solidification of the building material can be effected for example by supplying heat energy to the building material

Methodology Applied
Scientific EffectMelting and solidification: Melting

Implementation Method 4

unsolidified powder adjacent to material that is being solidified is not a good heat conductor. Thus, when the building material is irradiated, at positions adjacent to unsolidified powder the temperature will be higher

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3563203B1Control data for manufacturing one three-dimensional object by means of a layer-wise solidification of a building material
Publication Date: 2021.08.11 EOS GMBH ELECTRO OPTICAL SYST
  • EP3563203B1 patent drawingFigure 1
  • EP3563203B1 patent drawingFigure 2
  • EP3563203B1 patent drawingFigure 3

AI summary

A method for providing control data for manufacturing at least one three-dimensional object by means of a layer-wise solidification of a building material in an additive manufacturing apparatus is provided. The method includes at least the following steps: a) determining the locations corresponding to the cross section of the at least one object, b) determining at least two different regions to be solidified in said at least one layer, wherein said at least two regions are chosen from the group of: sandwiched region, down-facing region and up-facing region, c) defining a scanning sequence for the beam so as to solidify the building material at least at the locations corresponding to said portion of the cross section of the object, wherein at an interface between a first and a second region differing from each other a scan line of the beam is continuous and at least one beam parameter value is changed.