Additive Manufacturing Parameter Optimization via Response Surface

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Solution Overview

Problem

Current additive manufacturing (AM) parameter optimization methods are limited in handling dynamic processes, latency effects, and inter-batch variability of raw materials, leading to sub-optimal product quality and non-reproducibility across different equipment and material batches.

Innovation Solution

A method and system that determine optimal process parameters by generating test samples with varying parameter sets, measuring properties, fitting data to a second-order function, and adjusting parameters for a global optimum, accounting for latency and batch-specific variations using orthogonal array composite design and parabolic response surface analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If trial-and-error methodology or response surface methodology is used to study limited combinations of parameters, then the number of experiments is reduced, but the method is not fully portable for different printers and materials due to unsteady latency effect

Engineering Contradiction:
Improvenumber of experimentsVSAvoidportability for different printers and materials
Core Design Contradiction:
Loss of timeVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by transitioning from static endpoint optimization to dynamic real-time optimization. The system continuously monitors process parameters during additive manufacturing and adjusts parameters dynamically to compensate for latency effects, making the optimization method adaptable to different printers and materials while reducing the number of experiments needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback mechanisms by measuring actual process parameters during manufacturing and using this information to adjust parameters in real-time. This closed-loop feedback system enables portability across different printers and materials by automatically adapting to specific equipment characteristics and material behaviors without requiring extensive preliminary experiments.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If search-for-all approach is used to optimize AM parameter combinations, then all parameter combinations are evaluated, but the computational task becomes prohibitive due to NP search space size

Engineering Contradiction:
Improveoptimization accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by transforming the optimization problem from evaluating all NP parameter combinations to using a reduced set of key parameters with continuous adjustment. The system identifies critical parameters and optimizes them continuously during manufacturing, achieving high optimization accuracy while avoiding the prohibitive computational complexity of exhaustive search.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements partial action by focusing optimization efforts on the most critical parameters rather than all parameters. The system selectively monitors and adjusts key process parameters in real-time, achieving effective optimization with reduced computational burden compared to optimizing all parameters simultaneously.

Inventive Principle:
Principle #16Partial or excessive action

3Stability of the object's composition

If same parameters are used on different printers, then parameter consistency is maintained, but non-reproducibility occurs due to variations in energy delivery system, cooling system and powder-delivery system

Engineering Contradiction:
Improveparameter consistencyVSAvoidreproducibility across different printers
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent uses feedback to measure actual process parameters during manufacturing on each specific printer and adjusts parameters accordingly. This real-time feedback mechanism compensates for equipment variations, enabling consistent and reproducible results across different printers while maintaining parameter adaptability to each specific system's characteristics.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies local quality by tailoring process parameters to each specific printer's characteristics and conditions. Rather than using universal fixed parameters, the system adapts parameters locally to each printer's energy delivery system, cooling system, and powder-delivery system, ensuring optimal and reproducible results for each specific equipment configuration.

Inventive Principle:
Principle #3Local quality

4Device complexity

If optimization is based only on endpoint product, then simplicity is maintained, but dynamic process optimization during manufacturing cannot be achieved

Engineering Contradiction:
Improveoptimization method simplicityVSAvoiddynamic optimization capability
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent implements continuity of useful action by extending optimization from a static endpoint assessment to continuous real-time optimization during the entire manufacturing process. The system continuously monitors parameters and makes adjustments throughout manufacturing, maintaining simplicity in the optimization algorithm while achieving continuous dynamic optimization that improves productivity and part quality.

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 significantly reduces the number of experimental runs required for optimization, allows real-time adjustment of parameters, and ensures consistent high-quality products across different batches and equipment, effectively addressing latency and material variability issues.

Implementation Method 1

after melting or sintering of metal powders in a specific layer

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

after melting or sintering of metal powders in a specific layer

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 3

the local temperature will drop from the melting temperature to the printer chamber temperature quickly. The microstructures of the specific layer, and also the previous layers, can be altered by the dynamic heat transfer rate

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 4

this fast solidification process will induce residual stress from a mismatch in the thermal expansion coefficient of the liquid melt pool and solidified parts

Methodology Applied
Scientific EffectSolidification: Freezing

Implementation Method 5

residual stress from a mismatch in the thermal expansion coefficient of the liquid melt pool and solidified parts

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 6

in heat-treatment of single metal or alloy parts, the distribution of the compositions and the microstructures depend on the cooling rate after the material is moved out of the furnace

Methodology Applied
Scientific EffectCooling rate: Cooling

Data Source

PatentUS20230166332A1Optimising process parameters in additive manufacturing
Publication Date: 2023.06.01 NATIONAL UNIVERSITY OF SINGAPORE
  • US20230166332A1 patent drawing
  • US20230166332A1 patent drawing
  • US20230166332A1 patent drawing

AI summary

A method of determining optimal values of one or more process parameters for printing a part comprises obtaining a plurality of sets of test values for the one or more process parameters. An additive manufacturing system is caused to at least partially generate a plurality of test samples according to a design and the plurality of sets of test values. During or after generation of the plurality of test samples, test data indicative of respective measurements of at least one property of the test samples are obtained. The test data are fitted to a second-order function of the one or more process parameters to determine coefficients of the one or more process parameters. Based on the second-order function and the coefficients, optimal values are determined for the one or more process parameters that result in a global optimum for the at least one property.