Technológ - Ročník 16.; Číslo 2/2024
Permanent URI for this collectionhttps://drepo.uniza.sk/handle/hdluniza/1087
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Item Barkhausenov šum po dynamickom guľôčkovaní duplexnej ocele AlSi 318(University of Žilina, 2024) Mičietová, Anna; Uríček, Juraj; Čilliková, Mária; Neslušan, MiroslavThis paper deals with surface integrity and the corresponding Barkhausen noise after shot peening of duplex steel AlSi 318 under variable shot-peening conditions such as number of passes and applied air pressure. Surface state is investigated from the point of view of surface roughness and surface plastic deformation. Barkhausen noise is decreasing along with increasing surface coverage as well as increasing air pressure. The duplex matrix is considered being stable with respect of volume fraction between austenite and ferrite and the whole Barkhausen noise signal originates from ferromagnetic ferrite. Progressively developed plastic deformation increases dislocation density in the surface as a result of surface bombardment by shots which in turn shift Barkhausen envelopes into higher magnetic fields.Item Vplyv teploty na Barkhausenov šum v Co a Gd(University of Žilina, 2024) Neslušan, Miroslav; Čížek, Jakub; Mičietová, Anna; Čilliková, MáriaThe present paper deals with Barkhausen noise emission in Gd. Barkhausen noise emission was investigated in the temperature range mainly below the Gd Curie temperature when the spontaneous magnetization in Gd occurs. Barkhausen noise from the heavy rare-earth Gd is compared with Barkhausen noise emission from the transition metal Co measured at the same magnetizing and other conditions. This study demonstrates that Barkhausen noise emitted from Gd is much weaker than that originating from Co. This is a consequence of different spin exchange interaction among the neighbouring atoms, domain wall thickness as a well as domain wall energies. Moreover, Barkhausen noise is temperature sensitive especially for Gd sample as a result of the altering magneto-crystalline anisotropy.