Papers by Fausto Fiorillo
International Journal of Applied Electromagnetics and Mechanics
We present the results of an international comparison regarding the magnetic properties of hard m... more We present the results of an international comparison regarding the magnetic properties of hard magnets, measured using the Vibrating Sample Magnetometer. The comparison involved eight different international laboratories, plus two laboratories using the SQUID magnetometer. It was directed, in particular, at the determination of the hysteresis loop parameters of hard ferrite and magnetic tape samples. It was carried out in the framework of the activity of the IEC TC68 Working Group 2. The statistical analysis of the obtained results was performed according to standard rules (e.g. ISO and EURAMET guidelines). The standard deviation around the mean of the laboratories best estimates is found to be s ∼ 1% in anisotropic ferrites for all the measured quantities: coercive fields HcJ and HcB, high-field polarization J 800 k , polarization at remanence Jr, maximum energy product (BH)max. Isotropic ferrites show larger dispersion of the best estimates of Jr and HcB (∼ 3%) and (BH)max (∼6%). For the quantities measured in the magnetic tapes (magnetic moment under applied field H = 400 kA/m m 400 k and at remanence mr, squareness S = m 400 k /mr, HcJ)s is found to fluctuate around 2%. In all cases, the relative expanded uncertainty of the reference value (weighted mean), associated with a 95% confidence level, is at most ±1.5%.
International Journal of Applied Electromagnetics and Mechanics
We review state-of-the-art modeling of two-dimensional (2D) magnetization process in soft magnets... more We review state-of-the-art modeling of two-dimensional (2D) magnetization process in soft magnets. Emphasis is placed on the phenomenological assessment of the energy losses in steel sheets under rotational field. It is stressed that a general physically based theoretical framework, exploitable for applications in practical materials and machine cores, is not available at present. However, a rational approach to the 2D magnetic losses and their frequency dependence can be pursued. This is based on the separation between quasi-static (hysteresis) and dynamic magnetization processes and the connection with their unidirectional (scalar) counterpart. A number of vector models of the 2D quasi-static hysteresis behavior, typically residing on assessed scalar models, are discussed. They have prevalent formal-mathematical character, and, while being often helpful in numerical calculations, they leave unanswered the quest for solid physical interpretation. The dynamic magnetization process can, on the other hand, rely on a 2D phenomenological extension of the firmly established physical approach to the unidirectional scalar case provided by the statistical theory of losses. This is especially true for isotropic (i.e. nonoriented) magnetic laminations, where both rotational and elliptical flux loci can be conveniently handled. It permits one to achieve general appraisal of the experiments and flexible formulation, useful for numerical applications in machine cores.
IEEE Transactions on Power Electronics
Power losses in soft magnetic laminations under DC-biased supply are predicted by applying two di... more Power losses in soft magnetic laminations under DC-biased supply are predicted by applying two different approaches. A simple analytical formulation, based on the concept of loss separation, is provided first, which requires the knowledge of a major quasi-static hysteresis loop and two-frequency conventional loss measurement as the sole input information. A numerical finite element solution to the electromagnetic field distribution
Journal of Magnetism and Magnetic Materials, Sep 1, 2006
Tight control of flux loci in 2D testing of soft magnetic laminations is realized by a method bas... more Tight control of flux loci in 2D testing of soft magnetic laminations is realized by a method based on the principle of contraction mapping. It is implemented through digital control of the currents supplying a three-phase yoke magnetizer and the use of circular samples. Faithful realization of the prescribed loci and good measuring accuracy are demonstrated in grain-oriented and non-oriented
Techniques De L Ingenieur Genie Electrique, 2009
IEEE Transactions on Aerospace and Electronic Systems, 2015
A magnetic damping system for nanospacecraft attitude stabilization is proposed, based on the use... more A magnetic damping system for nanospacecraft attitude stabilization is proposed, based on the use of thin strips of amorphous Fe-B-Si soft magnetic ribbons. The size, number, and location of the strips is optimized, and a predictive formulation is provided. The main result of ground tests, comparing the performance of several soft magnetic materials, is that suitably heat-treated amorphous ribbons provide the best loss performance in the whole range of magnetic fields expected in orbit.
... The late Andrea Ferro Milone introduced me to materials science and Piero Mazzetti taught me ... more ... The late Andrea Ferro Milone introduced me to materials science and Piero Mazzetti taught me the basic virtues of the experimental ... Vittorio Basso, Cinzia Beatrice, Enzo Ferrara, and Eros Patroi kindly supplied me with their own experimental data and Marco Coisson clarified to ...
IEEE Transactions on Magnetics
This paper shows that it is possible to accurately predict power losses in ferromagnetic laminati... more This paper shows that it is possible to accurately predict power losses in ferromagnetic laminations under nonsinusoidal magnetic flux by specifically considering the dependence of hysteresis, classical, and excess loss components (
Journal of Applied Physics
Rotational energy losses W, have been measured as a function of magnetizing frequency f, and work... more Rotational energy losses W, have been measured as a function of magnetizing frequency f, and working induction B, in non-oriented SiFe laminations and compared with losses in alternating fields W,. I+', and W, exhibit a same non-linear dependence on f,,,, while the ratio W,/W, is a monotonically decreasing function of B,. A phenomenological approach to the behavior of hysteresis and excess rotational loss components is discussed.
Key Engineering Materials, 1994
Journal of Optoelectronics and Advanced Materials
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Papers by Fausto Fiorillo