Integrating Multi-Physics Simulations and Machine Learning to Define the Spatter Mechanism and Process Window in Laser Powder Bed Fusion

TL;DR

This paper combines high-fidelity multi-physics simulations and machine learning to analyze spatter formation in laser powder bed fusion, aiming to improve understanding and control of defects affecting mechanical properties.

Contribution

It introduces a novel multi-physics simulation tool for detailed spatter and meltpool analysis and applies machine learning to classify spatter behavior with high accuracy.

Findings

High correlation between spatter and meltpool features.

ML models achieved up to 96% accuracy in classifying spatter.

Dataset includes detailed features like velocity, temperature, and pressure.

Abstract

Laser powder bed fusion (LPBF) has shown promise for wide range of applications due to its ability to fabricate freeform geometries and generate a controlled microstructure. However, components generated by LPBF still possess sub-optimal mechanical properties due to the defects that are created during laser-material interactions. In this work, we investigate mechanism of spatter formation, using a high-fidelity modelling tool that was built to simulate the multi-physics phenomena in LPBF. The modelling tool have the capability to capture the 3D resolution of the meltpool and the spatter behavior. To understand spatter behavior and formation, we reveal its properties at ejection and evaluate its variation from the meltpool, the source where it is formed. The dataset of the spatter and the meltpool collected consist of 50 % spatter and 50 % melt pool samples, with features that include position components, velocity components, velocity magnitude, temperature, density and pressure. The relationship between the spatter and the meltpool were evaluated via correlation analysis and machine learning (ML) algorithms for classification tasks. Upon screening different ML algorithms on the dataset, a high accuracy was observed for all the ML models, with ExtraTrees having the highest at 96 % and KNN having the lowest at 94 %.