Untersuchungen zur Unterdrückung des Portevin-LeChatelier-Effekts bei AlMg-Legierungen und partikelverstärkten Verbundwerkstoffen (English shop)

Experimente, Mikrostruktur und Modellierung

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Hanno Dierke’s dissertation investigates approaches to suppressing the Portevin–Le Chatelier (PLC) effect in aluminium–magnesium alloys and particle-reinforced metal matrix composites. This phenomenon causes localized plastic deformation, stress fluctuations and undesirable surface irregularities during material processing.

The research focuses on the aluminium alloys AA5754 and AA6061 and their reinforcement with alumina particles (Al₂O₃). Experimental tensile testing, electron microscopy, optical extensometry and numerical modelling are employed to examine the relationships between microstructure, dislocation motion, precipitation behaviour and deformation instabilities.

The findings demonstrate that a homogeneous distribution of reinforcing particles and sufficiently small distances between dislocation obstacles can significantly reduce or suppress plastic instabilities. The dissertation contributes to a better understanding of deformation mechanisms and provides valuable insights into improving the mechanical behaviour of metallic materials.