Master's Thesis

Development of a Machine Learning Framework for interlayer dwell time prediction in Wire-Arc Additive Manufacturing

João Pereira Vieira Alexandre2026

Key information

Authors:

João Pereira Vieira Alexandre (João Pereira Vieira Alexandre)

Supervisors:

Susana Margarida da Silva Vieira (Susana Margarida da Silva Vieira); Rui Filipe Vieira Sampaio (Rui Filipe Vieira Sampaio)

Published in

June 29, 2026

Abstract

Wire-Arc Additive Manufacturing (WAAM) enables the production of large-scale metallic components with a high deposition rate, but remains limited by thermal accumulation and geometric variability, which are affected, in part, by the empirical selection of the interlayer dwell time. This dissertation develops an approach to automatically predict, prior to production, the dwell time required to achieve a defined interlayer transition temperature. An experimental database was built comprising 81 straight walls of 316LSi stainless steel, each with 20 layers, varying the torch travel speed, wire feed speed, transition temperature, and deposited bead length. The dwell times were obtained by infrared thermography and used to train machine learning (ML) models suitable for regression problems. Several models were evaluated, and Support Vector Regressors (SVR) were selected, subsequently optimised and integrated into a predictive tool in Python. In the validation trials, the SVRs reproduced the measured dwell times with high accuracy and allowed stable transition temperatures to be achieved. Interpolation and extrapolation conditions were tested, as well as a simple curved geometry. The work demonstrates the feasibility of offline predictions to support thermal and production planning in WAAM, reducing dependence on empirical procedures.

Publication details

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Fields of Science and Technology (FOS)

mechanical-engineering - Mechanical engineering

Publication language (ISO code)

eng - English

Rights type:

Embargoed access

Date available:

April 9, 2027

Institution name

Instituto Superior Técnico