Development of a Winding Mechanism for Amorphous Ribbon Used in Transformer Cores

M. R. PAGNOLA; R. KATABIAN

Mechanical Engineering

InTech

Año: 2012; p. 277 - 291

In recent years, the application range of available soft magnetic materials has increased significantly due to the development of amorphous and nano-crystalized systems. Certain ferromagnetic alloys can be obtained as vitreous phases by rapid quenching techniques; some of them partially crystallize by certain heat treatments achieving structures composed by 10 to 40 nanometre long grains surrounded by a vitreous phase. One of these rapid quenching techniques is the melt-spinning, from which it is obtained amorphous metal strips that are, later, wound up into rolls. The later-use of the wound rolls is the conformation of electric transformer cores showing meaningful improvement in its overall outputs, as well as an increment in the efficiency and fewer environmental impacts. In the past, these cores have been produced with grain- oriented and non-grain-oriented silicon steel sheets, ferrite sheets, Ni-Fe and Co-Fe alloys sheets produced by conventional casting processes, which require several mechanical and thermal processes, which some of them, have a high cost (Gelinas, 2000). The fabrication of nano-structured magnetic packages can be done, in this particular case, by the direct employment of melt-spinning´s strips into different kinds of heat treatments, where it can also be adjusted the hysteresis cycle. Furthermore, its uses can be extended to complex geometries introducing a milling stage after the melt-spinning process, obtaining refined elemental powder particles (Nowacki, 2006; Byoung et al., 2007), which its dimensions can be modified by the control of the milling stage time (Dobrzanskia et al, 2004). The connotations of using soft magnetic alloys affect not only transformer cores but also AC motors (Pagnola et al., 2009; Pagnola, 2009). These new amorphous and nano-crystalized materials are currently sold up to 3 times the price of conventional materials (Condes, 2008).