Powder Reuse Index for LPBF Build Powder Quality

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In laser powder bed fusion additive manufacturing, reused build powder often experiences heat stress, leading to parts that may fall out of material strength specifications, making it challenging to determine whether the powder is still fit for reuse while maintaining quality.

Innovation Solution

A method is developed to calculate a Powder Reuse Index based on LPBF process operating parameters, using statistical coefficients and quality characteristics of test pieces to assess the suitability of build powder for reuse, allowing for efficient determination of whether the powder meets quality specifications without repetitive testing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If build powder is reused to reduce costs, then manufacturing cost decreases, but part quality may deteriorate due to heat stress accumulation

Engineering Contradiction:
Improvebuild powder costVSAvoidpart quality
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The patent transforms the quality assessment from binary (usable/unusable) to a continuous parameter (Powder Reuse Index) that quantifies powder quality degradation. This index incorporates multiple process parameters (laser power, scan speed, hatch spacing, layer thickness) and quality characteristics (porosity, mechanical properties, microstructure) to dynamically evaluate powder suitability for reuse, enabling optimized reuse decisions that balance cost and quality.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If extensive testing is performed to ensure powder quality, then part quality reliability improves, but time consumption and complexity increase

Engineering Contradiction:
Improvepowder quality assuranceVSAvoidtesting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary comprehensive testing and characterization of powder quality parameters before establishing the Powder Reuse Index model. This initial investment in data collection (testing multiple build parameters, measuring porosity, mechanical properties, and microstructure) creates a robust predictive model that eliminates the need for repetitive testing during subsequent powder reuse evaluations, significantly reducing time consumption while maintaining high reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates a virtual model (Powder Reuse Index) that replicates the complex relationship between process parameters and quality outcomes. Instead of physically testing powder batches repeatedly, the system uses this computational model to predict powder quality, replacing time-consuming physical testing with rapid computational assessment while preserving reliability.

Inventive Principle:
Principle #26Copying

3Manufacturing precision

If frequent quality testing is conducted to monitor powder degradation, then manufacturing precision is maintained, but productivity decreases

Engineering Contradiction:
Improvequality specification complianceVSAvoidbuild throughput
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces frequent physical quality testing with a computational copy (Powder Reuse Index calculation) that rapidly assesses powder quality based on process history and material characteristics. This virtual assessment maintains quality specification compliance detection while eliminating the time delays associated with physical testing, thereby preserving build throughput and productivity.

Inventive Principle:
Principle #26Copying

4Productivity

If build powder is reused without assessment, then productivity increases, but manufacturing precision deteriorates

Engineering Contradiction:
Improvepowder reuse efficiencyVSAvoidmaterial strength specification
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system enables self-service quality assessment where the Powder Reuse Index automatically evaluates powder suitability for reuse based on integrated process parameters and material characteristics. This automated self-assessment eliminates the need for external quality intervention while maintaining material strength specification compliance, allowing high-speed powder reuse decisions that preserve both productivity and manufacturing precision.

Inventive Principle:
Principle #25Self-service

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 method enables the reuse of build powder while ensuring parts meet quality specifications, reducing costs and time by characterizing powder suitability for reuse without frequent testing, thereby optimizing the use of build powder and minimizing new powder costs.

Implementation Method 1

Laser Powder bed fusion (LPBF) additive manufacturing is an additive manufacturing, or 3-D printing, technology that uses a laser to sinter or fuse metallic or polymeric particles together

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

Some LPBF processes sinter the build powder particles

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 3

others melt and fuse the build powder particles

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP4523887A1Determing quality of build powder for additive manufacturing on reusability
Publication Date: 2025.03.19 RTX CORP
  • EP4523887A1 patent drawingFigure 1~2
  • EP4523887A1 patent drawingFigure 3
  • EP4523887A1 patent drawingFigure 4

AI summary

A method for determining whether build powder is fit for reuse in a laser powder bed fusion additive manufacturing (LPBF) process includes constructing a model for determining a Powder Reuse Index indicative of whether build powder is fit for reuse in the LPBF process based upon LPBF process operating parameters. A build design is selected to be built using the LPBF process to collect data for constructing the model for determining the Powder Reuse Index. A plurality of test pieces the selected build design are built using a LPBF system with different layouts or set ups. Quality characteristics are determined for each of the plurality of test pieces and, using the quality characteristics for each of the plurality of test pieces, a relative importance of each LPBF process build parameter as to whether a batch of build powder is fit for reuse is determined.