Amorphization and microstructural evolution in multicomponent (FeCoNi) 70Zr10B20 alloy systems by mechanical alloying process

High energy ball milling of a mixture of elemental and prealloyed powder for 18-27 h has led to an amorphous structure in the multicomponent (Fe1-x-yCoyNix)(70)Zr10B20 (x = 0.1-0.4, y = 0, 0.1, 0.3) alloy system. Initially, the starting powder material with mixed crystalline phases transformed into an almost single nanocrystalline supersaturated alpha -Fe phase after milling for 6 h. Subsequently, the milled powders became less crystalline and more amorphous with further increase in milling time. Co-free (Fe1-xNix)(70)Zr10B20 (x= 0.1, 0.2, 0.3) alloys and the Go-containing (Fe0.6Co0.1Ni0.3)(70)ZR(10)B(20) alloy tend to readily transform to amorphous structure after milling for 18 h. But Co-free (Fe1-xNix)(70)Zr10B20 (x = 0.3) alloy produced a mixture of nanocrystalline boron-rich phase and amorphous phase after milling for 18 h. However, Go-containing (Fe0.6Co0.3Ni0.1)(70)Zr10B20 and (Fe0.8Co0.1Ni0.1)(70)Zr10B20 alloys with a low Ni/Co ratio failed to achieve amorphization even after 27 h. For all milled amorphous alloy powders, the glass transition temperatures, the onset crystallization temperatures lie in 544-577 and 579-619 K range, respectively. The supercooled liquid regions varied from 35 to 42 K, and the crystallization enthalpies varied from 3.2 to 6.9 kJ mol(-1) with a change in Ni/Fe ratio. (C) 2001 Elsevier Science B.V. All rights reserved.