Green Body Mesh Compensation for Sintering-Induced Distortion

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Solution Overview

Problem

Additive manufacturing techniques, such as binder jetting, face challenges in producing parts with accurate geometry due to sintering-induced distortion, which can result in varying degrees of deformation and deviation from the desired shape, requiring effective compensation methods to achieve precise final parts.

Innovation Solution

A method and system that perform a sintering analysis incorporating loading conditions like gravity and friction to predict nodal displacements, allowing for the generation of a distortion-compensated geometry by adjusting the green body part mesh nodes to align with a desired model mesh, ensuring the printed part meets a predetermined tolerance and maintaining the desired shape post-sintering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If sintering is performed to densify the green body part, then the part achieves desired density and strength, but the part undergoes distortion and deformation from varying forces during sintering

Engineering Contradiction:
ImprovedensityVSAvoiddistortion
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The system performs sintering analysis and calculates nodal displacements before actual manufacturing, then applies distortion compensation to the green body part geometry in advance. This preliminary action predicts and counteracts the distortion that will occur during sintering, ensuring the final part achieves the desired shape while maintaining the benefits of sintering densification.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If distortion compensation is applied to the green body part geometry, then the final part shape accuracy is improved, but the complexity of the manufacturing process increases

Engineering Contradiction:
Improveshape accuracyVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system replaces complex physical trial-and-error prototyping with computational sintering analysis and finite element modeling. By using software-based distortion prediction and compensation calculations, the system achieves high shape accuracy without requiring multiple physical prototypes or iterative manual adjustments, thus reducing overall process complexity despite adding computational steps.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 enables the production of parts with complex geometries, reduces the need for redesign and prototypes, and lowers development costs by accurately predicting and compensating for sintering-induced distortions, thereby enhancing the capabilities of binder jet additive manufacturing.

Implementation Method 1

the green body part may be inserted in a sintering furnace that heats the green body part to elevated temperatures (e.g., greater than or equal to about 500°C) to remove the binder and solidify the powder particles to one another

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 2

Solidification of the green body part may result in distortion of the green part's shape. As the green body part shrinks from sintering-induced densification, different portions of the green body part may be subjected to varying degrees of forces

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3996053A1Systems and methods for compensating a geometry of a green body part based on sintering-induced distortion
Publication Date: 2022.05.11 GENERAL ELECTRIC CO
  • EP3996053A1 patent drawingFigure 1
  • EP3996053A1 patent drawingFigure 2A~2B
  • EP3996053A1 patent drawingFigure 3

AI summary

A method of generating a distortion-compensated geometry for a workpiece includes generating a green body part geometry for the workpiece, discretizing the green body part geometry into a green body part mesh and performing a first sintering analysis on the green body part mesh to generate a post-sintering mesh based on the green body part mesh, the post-sintering mesh including a plurality of post-sintering mesh nodes. The method also includes co-registering the post-sintering mesh and a model mesh having a geometry corresponding to the three-dimensional model, the model mesh including a plurality of model mesh nodes. For each of the plurality of post-sintering mesh nodes, a displacement between a post-sintering mesh node and a corresponding model mesh nodes is determined, and the green body mesh may be adjusted based on the displacement to generate the distortion-compensated geometry.