Print Email Facebook Twitter Defect evolution during annealing of deformed FeSi alloys studied by positron annihilation spectroscopy Title Defect evolution during annealing of deformed FeSi alloys studied by positron annihilation spectroscopy Author Mostafa, K.M. González Cámara, F. Petrov, R. Rodriguez Calvillo, P. De Grave, E. Segers, D. Houbaert, Y. Faculty Mechanical, Maritime and Materials Engineering Department Materials Science and Engineering Date 2011-03-18 Abstract High silicon steel is widely used in electrical appliances. Alloying iron with silicon improves its magnetic performance. A silicon content up to 6.5 wt. % gives excellent magnetic properties such as high saturation magnetization, near zero magnetostriction and low iron loss in high frequencies. Their workability is greatly reduced by the appearance of ordered structures, namely B2 and D03, as soon as the Si content becomes higher than 3.5 wt. %. This limits the mass production by conventional rolling to this maximum percentage of Si. In this work a series of FeSi (7.5 wt. % Si) samples with different degrees of deformation are investigated with positron annihilation spectroscopy and optical microscopy (OM). The influence of annealing on the concentration of defects of different deformed FeSi alloys has been investigated by positron annihilation lifetime spectroscopy and Doppler broadening of the annihilation radiation. OM is used to investigate the microstructure of deformed samples before and after annealing. The values of the S parameter present a decrease for all studied FeSi alloys with the increase of the annealing temperature, being attributed to a decrease of the concentration of defects. A sudden increase of the S-parameter value at 600?°C was observed for all samples, which could be related to the change of the ordering of the FeSi alloys at that temperature. At 700 °C, the values of the S parameter decreased drastically and starting from 900?°C, they became constant. The microstructures of the alloys, investigated by OM, show that recrystallization is completed at 900?°C and the samples are mainly free of defects, which is in agreement with the positron annihilation lifetime data. Subject annealingcrystal microstructuredeformation, Doppler broadeningferromagnetic materialsiron alloysmagnetisationmagnetostrictionoptical microscopypositron annihilationrollingsilicon alloys To reference this document use: http://resolver.tudelft.nl/uuid:f0a38980-f041-41ca-9585-9e0b89963d8d DOI https://doi.org/10.1063/1.3535424 Publisher American Institute of Physics ISSN 0021-8979 Source http://link.aip.org/link/doi/10.1063/1.3535424 Source Journal of Applied Physics, 109 (7), 2011 Part of collection Institutional Repository Document type journal article Rights © 2011 The Author(s)American Institute of Physics Files PDF Petrov_2011.pdf 539.59 KB Close viewer /islandora/object/uuid:f0a38980-f041-41ca-9585-9e0b89963d8d/datastream/OBJ/view