Dresden 2006 – wissenschaftliches Programm

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MM: Metall- und Materialphysik

MM 13: Symposium Modern Metallic Materials Design III

MM 13.4: Vortrag

Dienstag, 28. März 2006, 11:00–11:15, IFW B

Solidification and magnetic properties of Fe-Cr-Mo-Ga-P-C-B bulk metallic glasses — •Jürgen Eckert¹, Mihai Stoica^2,3, Nicolle Radtke², Stefan Roth², Ludwig Schultz², Jürgen Eckert¹, and Wei Hua Wang⁴ — ¹Darmstadt University of Technology, Petersenstr. 23, D-64287 Darmstadt, Germany — ²IFW Dresden, PF 270016, D-01171 Dresden, Germany — ³Present address : LTPCM-CNRS UA29, INP Grenoble 38402, France — ⁴Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China

Our work focused on (Fe_{77.5−x−y−z}Cr_xMo_yGa_zP₁₂C₅B_5.5 with (x,y,z) = (4,4,4), (4,4,2), (4,4,0) and (2,2,2)) alloys, which were cast into different geometries. The structure of the samples was checked by X-ray diffraction. Thermal stability studies and isothermal annealing were done in a differential scanning calorimeter (DSC). The fracture strength for the as-cast samples is around 3 GPa and the fracture strain reaches 2%. The Vickers hardness HV for the as-cast samples is about 885, and increases to 902 upon annealing. The fracture of this Fe-based BMG is not propagating along a well-defined direction and the fractured surface looks irregular. Instead of veins, the glassy alloy develops a high number of microcracks. The coercivity of as-cast samples is lower than 10 A/m, decreasing to 0.7 A/m after annealing. The saturation polarization at room temperature is around 0.8 T, increasing up to 1 T at 77 K. This work was funded by the National Science Foundation of China (Grants No. 50371098 and 50321101), the Chinesisch-Deutsches Zentrum für Wissenschaftsförderung (Grant No. GZ032/7) and the Deutsche Forschungsgemeinschaft (Grant Ec 111/12)