TY - THES

T1 - Investigation of the crystallization behavior of iron-based metallic glasses for electrical devices

AU - Römer, Felix Josef

N1 - no embargo

PY - 2022

Y1 - 2022

N2 - The ongoing environmental crisis requires a significant reduction in power consumption. Hysteresis and eddy current losses are the two main types of losses in transformers and electric motors. Hysteresis losses are caused by changes in magnetic alignment. Eddy current losses are caused by induction currents inside an electrically conductive material. Reducing these losses is essential to achieving climate goals. Amorphous cores have proven that they can significantly reduce losses in transformers. In this work, the thermal and structural properties of two alloys, Fe60Co15Ni5P13C7 and Fe74Mo4Si2P10C7.5B2.5, were investigated. They were fabricated as amorphous ribbons and rods and analyzed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Isothermal heat treatments at different temperatures and subsequent XRD measurements were performed. In addition, FDSC measurements were performed in the laboratory to investigate crystallization behavior at high heating rates. To investigate the time and temperature changes at high heating rates, Fe74Mo4Si2P10C7.5B2.5 was studied using in-situ flash DSC measurements in the synchrotron. For this purpose, a python-script for rapid preparation and analysis of synchrotron data was developed.

AB - The ongoing environmental crisis requires a significant reduction in power consumption. Hysteresis and eddy current losses are the two main types of losses in transformers and electric motors. Hysteresis losses are caused by changes in magnetic alignment. Eddy current losses are caused by induction currents inside an electrically conductive material. Reducing these losses is essential to achieving climate goals. Amorphous cores have proven that they can significantly reduce losses in transformers. In this work, the thermal and structural properties of two alloys, Fe60Co15Ni5P13C7 and Fe74Mo4Si2P10C7.5B2.5, were investigated. They were fabricated as amorphous ribbons and rods and analyzed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Isothermal heat treatments at different temperatures and subsequent XRD measurements were performed. In addition, FDSC measurements were performed in the laboratory to investigate crystallization behavior at high heating rates. To investigate the time and temperature changes at high heating rates, Fe74Mo4Si2P10C7.5B2.5 was studied using in-situ flash DSC measurements in the synchrotron. For this purpose, a python-script for rapid preparation and analysis of synchrotron data was developed.

KW - Kristallisation

KW - metallische Gläser

KW - Röntgendiffraktometrie

KW - Synchrotron

KW - Entglasung

KW - dynamische Differenzkalorimetrie

KW - crystallization

KW - bulk metallic glass

KW - iron-based bulk metallic glass

KW - devitrification

KW - X-ray diffraction

KW - Flash DSC

KW - DSC

KW - thermal properties

M3 - Master's Thesis

ER -