Optimal parameters for single-crystal laser metal deposition

Autor*in: Irene Priyadharshini Buchbender

ISBN: 978-3-69030-135-0

Dissertation, Leibniz Universität Hannover, 2025

Herausgeber*in der Reihe: Stefan Kaierle, Dietmar Kracht

Band-Nr.: LZH 04/2025

Umfang: 110 Seiten, 66 Abbildungen

Schlagworte: laser metal deposition, epitaxial, single-crystal

Kurzfassung: Single-crystal (SX) components have superior thermomechanical properties, however, due to their high cost and limited lifespan, there arises a need for an adequate repair. Laser metal deposition is an established repair process, however, the difficulty in repairing SX components is achieving the same microstructure in the deposit as in the substrate. Optimal parameters were determined for the deposition of single clads in terms of percentage single-crystallinity and the incidence of defects. This strategy was extended to lateral as well as multi-layered deposits. It was deduced that for lateral, SX processing of structures, in order to maintain the growth of [001] dendrites, the maximum processing angle must be 35°. Using the optimal parameters determined, a strategy for multi-layered parts was developed to deposit structures with up to 94.2% single-crystallinity. It was shown that explanatory modelling using multiple linear regression combined with the consideration of process-specific quality metrics enables the determination of optimal process parameters.