Modelling and analysis of isotropic thermal conductivity enhancement in laser melting and welding

Lau, Gabriel and Pinkerton, Andrew and Cheneler, David (2025) Modelling and analysis of isotropic thermal conductivity enhancement in laser melting and welding. PhD thesis, Lancaster University.

Text (2024lauphd)
2024lauphd.pdf - Published Version
Available under License Creative Commons Attribution-NonCommercial-NoDerivs.
Download (14MB)

Abstract

This thesis investigates the feasibility of simplifying laser welding simulations by introducing isotropic thermal conductivity enhancement while omitting the phase change mechanism. The aim is to simplify models without compromising accuracy in predicting conduction-based, mixed-mode, and keyholebased laser welding scenarios. The universal model’s development involves iterative comparisons between simulation data and extensive experiments conducted across a range of laser powers (200 W to 1200 W) and traverse speeds (10 mm/s to 34 mm/s). This dataset enables comprehensive calibration, refining the model through an understanding of melt pool formation in diverse laser melting processes. By excluding phase change and fluid flow simulations, the model strikes a balance between accuracy and computational efficiency. It successfully predicts melt pool dimensions, proving its ability to streamline simulations without compromising essential predictive aspects. The deliberate simplification, while resulting in a decrease in absolute accuracy, addresses the practical challenges associated with computational demands in traditional phase change simulations. This contributes to the field by providing a practical and efficient alternative for laser welding simulations. In conclusion, this work culminates in the development of a universal model to predict various laser melting and welding scenarios. It offers a streamlined approach for practical implementation and offers valuable insights to enable optimisation of laser material processing techniques of this type