Microwave-induced heating and sintering of metallic glasses

Metallic glasses exhibit low viscosity in a temperature range between the glass-transition and crystallization temperature which allows successful sintering of glassy powders. Microwave heating being a volumetric heating has significant advantages over conventional heating in materials processing, such as substantial energy savings, rapid heating rates and process cleanness. In the present study, we investigate the stability of the Fe73Si7B17Nb3, Fe65Co10Ga5P12C4B4, Ni52.5Zr15Nb10Ti15Pt7.5, Ni60Nb20Ti15Zr5, Zr55Cu30Al10Ni5 and Ti47.5Zr10Cu30Pd7.5Sn5 glassy powders and formation of the porous bulk metallic glassy samples by microwave heating in a single-mode cavity with separated electric (E) and magnetic (H) field maxima in an inert atmosphere. The Fe73Si7B17Nb3 and Fe65Co10Ga5P12C4B4 alloys crystallized upon MW heating in both E- and H-field maxima forming a nanostructure. The Ni52.5Zr15Nb10Ti15Pt7.5 and Zr55Cu30Al10Ni5 alloys were heated well in H-field and were not heated well enough in E-field. In case of Ni52.5Zr15Nb10Ti15Pt7.5 and Ni60Nb20Ti15Zr5 alloys sintered samples were obtained. (C) 2008 Elsevier B.V. All rights reserved.