arXiv subjects

Denis Dowling

Publications and source records attributed to Denis Dowling.

3 recordsLinked to original sources

arXiv2025

High-Throughput Unsupervised Profiling of the Morphology of 316L Powder Particles for Use in Additive Manufacturing

Selective Laser Melting (SLM) is a powder-bed additive manufacturing technique whose part quality depends critically on feedstock morphology. However, conventional powder characterization methods are low-throughput and qualitative, failing to capture the heterogeneity of industrial-scale batches. We present an automated, machine learning framework that couples high-throughput imaging with shape extraction and clustering to profile metallic powder morphology at scale. We develop and evaluate three clustering pipelines: an autoencoder pipeline, a shape-descriptor pipeline, and a functional-data pipeline. Across a dataset of approximately 126,000 powder images (0.5-102 micrometer diameter), internal validity metrics identify the Fourier-descriptor + k-means pipeline as the most effective, achieving the lowest Davies-Bouldin index and highest Calinski-Harabasz score while maintaining sub-millisecond runtime per particle on a standard desktop workstation. Although the present work focuses on establishing the morphological-clustering framework, the resulting shape groups form a basis for future studies examining their relationship to flowability, packing density, and SLM part quality. Overall, this unsupervised learning framework enables rapid, automated assessment of powder morphology and supports tracking of shape evolution across reuse cycles, offering a path toward real-time feedstock monitoring in SLM workflows.

cs.CV↗

arXiv2025

Neuromorphic computing for anomaly detection in a laser powder bed fusion process

This study is the first application of spiking neural networks (SNNs) for anomaly detection in the Laser Powder Bed Fusion (LPBF) additive manufacturing process. The neural networks were used to identify print processing anomalies generated by dropping of laser energy during the printing of individual layers in a Ti-6Al-4V alloy lattice structures. Associated changes in the laser generated melt pool were observed using an in-process photodiode monitoring technique. photodiode sensors capturing plasma and infrared radiations reflected from the print bed of the metal 3D printer were utilized to detect sudden changes caused by anomalies during the printing process. The algorithm is first implemented on non-neuromorphic hardware including a central processing unit (CPU), on Field Programmable Gate Arrays (FPGA) and then on neuromorphic Intel's Loihi chip. Improved detection of anomalies is achieved by adjusting the spike latency of the neural network, which reduces masking of information by noise within the monitored temporal signal. The work demonstrates the possibility of using low-power neuromorphic chips within an edge framework for anomaly detection in additive manufacturing and creates a framework for the process.

eess.SP↗

arXiv2016

Prediction of tool-wear in turning of medical grade cobalt chromium molybdenum alloy (ASTM F75) using non-parametric Bayesian models

We present a novel approach to estimating the effect of control parameters on tool wear rates and related changes in the three force components in turning of medical grade Co-Cr-Mo (ASTM F75) alloy. Co-Cr-Mo is known to be a difficult to cut material which, due to a combination of mechanical and physical properties, is used for the critical structural components of implantable medical prosthetics. We run a designed experiment which enables us to estimate tool wear from feed rate and cutting speed, and constrain them using a Bayesian hierarchical Gaussian Process model which enables prediction of tool wear rates for untried experimental settings. The predicted tool wear rates are non-linear and, using our models, we can identify experimental settings which optimise the life of the tool. This approach has potential in the future for realtime application of data analytics to machining processes.

stat.AP↗