Shape memory alloys (SMAs) exhibit unique properties that make them ideal for functionally integrated components, such as actuators. While commonly used Ni-Ti alloys are well-established, especially in biomedicine and aerospace, their high cost limits wider applications. Fe-based SMAs present an affordable alternative, suitable for diverse applications, with a larger thermal hysteresis but lower recovery strain. Nonetheless, their functional properties can be enhanced through optimized processing methods like laser powder bed fusion and adjustments to their alloy composition. However, attributing the functional improvements to individual factors is complex due to interdependency and inseparability of some factors.
In order to address this ambiguous state of literature, a novel approach for modifying the chemical composition of a FeMnSiCr-alloy will be presented. The technique allows in-situ re-alloying during laser powder bed fusion by locally applying a nanofluid containing the desired alloying element. This method offers a cost- and material-efficient high-throughput solution for alloy modification and functional grading.
Our current research focuses on utilizing this method to analyze the influence of interstitial atoms and carbide precipitates. For this purpose, specialized nanofluids for the flexible addition of necessary elements, such as carbon and niobium, were developed. Subsequently, the impact of the resulting compositional changes on the microstructure and the materials functional properties are analyzed.
The poster showcases the use of this novel re-alloying approach for the improvement of SMA composition and its possible application for functional grading.