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Amorphous Fe32Ni52Zr3B13, prepared by rapid solidification, undergoes crystallization during high-energy mechanical milling. The resulting structure consists of face-centered cubic (fcc) FeNi and Zr3Ni20B6 nanocrystallites. Structural evolution and defect analysis of as-solidified Fe32Ni52Zr3B13 ribbons with different milling times is investigated. From the differential thermal analysis (DTA) curve of amorphous ribbons, exothermic peaks were observed at 415 °C and 475 °C corresponding to the crystallization of fcc Zr3Ni20B6 phase and fcc FeNi phase, respectively. However, high-energy mechanical milling induces the formation of FeNi within the first 2 h of mechanical milling. Further milling induces the crystallization of Zr3Ni20B6. Doppler broadening positron annihilation spectroscopy (DBPAS) was used to investigate vacancy-type defects. The milling-induced crystallization appears to be related to enhanced vacancy-type defect concentrations allowing growth of pre-existing Fe(Ni) nuclei. The milling and enhanced vacancy concentration also de-stabilizes the glass, leading to decreased crystallization temperatures for both phases, and ultimately eliminating the glass transition altogether.

Minor alloying additions to Nd–Fe–B significantly alter the crystallization kinetics of the alloy. The crystallization behavior of stoichiometric Nd 2 Fe 14 B displayed conventional behavior, with an Avrami exponent, n , close to 3. TiC additions stabilized the glassy phase and contributed to a more uniform crystallized grain structure. The time to complete crystallization was extended, implying a change in crystallization kinetics. The kinetic behavior and microstructural evolution implied growth-controlled crystallization. However, substitution additions to form a nine-component alloy displayed anomalous crystallization behavior (large n ). EDS results, which showed partitioning of Ti and C, interfacial enrichment of the rare-earth elements, and interfacial depletion of Fe, suggested that diffusion processes may be important in this system, while microstructural development suggested that the transformation was dominated by a rapidly changing nucleation rate.

27Al and 63Cu Knight shift (K) and relaxation rates (T1−1) are compared for the quasicrystalline (QC) phase and the crystalline (C) phase of Al65Cu23Fe12, and for quasicrystals of Al85−xCuxRu15 with x = 17, 20. The 27Al K is small (K = 0.013 ± 0.003%) and temperature independent. Within error, no differences were found between QC- and C-phases of AlCuFe, nor between AlCuRu samples with x = 17, 20. 27Al and 63Cu T1−1 vs T in AlCuRu displays Korringa-like behavior in the range 5 < T < 50 K with T1T independent of composition. The NMR results are compared with specific heat data which change as a function of concentration x, suggesting large changes of density of states (DOS) at the Fermi level. The two sets of measurements could be reconciled by separating the s-band and d-band effects but the possibility that some of the observed effects are due to disorder modes cannot be ruled out.

Isothermal sections of the AlCuRu phase diagram at 500 and 800dgC have been determined for Al concentrations greater than 60 at.%. At 500°C, the icosahedral phase is not thermodynamically stable, whereas at 800°C it is stable over a fairly broad compositional region. The formation of the fci phase from the low temperature tetragonal phase is by a nucleation and growth process. The first-order transformation to the fci phase is endothermic, indicating that the fci phase is at a higher energy than the tetragonal phase.