Authors: Vladimir P Menushenkov Mikhail V Gorshenkov Elena S Savchenko Dmitry G Zhukov
Publish Date: 2014/12/12
Volume: 46, Issue: 2, Pages: 656-664
Abstract
The microstructure of ascast and melt spun AlNi alloys was studied by transmission TEM and scanning electron microscopy as well as atomic force microscopy AFM The magnetic properties of the alloys were measured using a vibrating sample magnetometer The water quenched and melt spun AlNi samples were characterized by zone microstructure formed as a result of solid solution decomposition into β and β2 phases within the miscibility gap Therefore the subsequent aging of asquenched alloy leads to the development of the zone microstructure instead of the decomposition of singlephase solid solution The absence of preferential precipitations and discontinuous precipitation DP reaction was observed at grain boundaries GB of ascast AlNi alloy after aging The antiphase domains APD have been observed for the first time in the AlNi ribbons prepared by melt spinning The effects of GB and APD boundaries on the decomposition of a solid solution in the AlNi ribbons were investigated At first a thin βphase layer is formed along GB and APD boundaries Then the decomposition leads to the formation of β2phase layers on the both sides of βphase layer The GB and APD boundaries which are decorated by precipitates of β and β2 layers become visible in the TEM and AFM micrographs A DP reaction at GBs has been observed for the first time in the AlNi ribbons after supplementary aging The cellular microstructure at GBs consisting of alternating lamellas of β′ and β′2 phases was formed after aging the ribbons at 773 K 500 °C for 10 minutesThis study was supported by the Ministry of Educations and Science of the Russian Federation and is performed in accordance with the project part of State Assignment no 1126162014/К for 2014 and in the framework of Increase Competitiveness Program of MISiS
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