Crystallization of CoFeSiB metallic glass induced by long-time ball milling

Structure and thermomagnetic properties of powders produced from melt spun FeNbBCu ribbons

“…Kollar et al [18] reports a two stage crystallization process in the DSC signal of the powder compared to a single peak for the ribbon. However, our results do not show changes in the XRD patterns of the REC powder indicating that no crystallization was induced during milling, in agreement with observations by other authors for longer milling times [8,10] and higher speeds [11]. Also, we observe no changes in the saturation magnetization confirming the absence of nanocrystallization induced by milling.…”

“…200 rpm ball-milling induces a broadening of both calorimetric and Bragg peaks compared to the sample milled at a lower speed. This effect may be explained by the creation of structural defects and partial amorphization of the nanocrystalline precursor ribbon with increasing milling speed [7,8,10]. Also higher milling times can induce the reamorphization of the sample [13].…”

“…Another interesting route is to use the ball-milling technique to transform the amorphous ribbons into powder so that powder-metallurgical techniques can be used to produce pieces with different shapes and dimensions. However, recent studies in amorphous alloys [7][8][9][10][11][12] show that ball-milling needs a careful control of precursor's state and processing parameters in order to avoid the suppression of good soft magnetic properties. Recently, the interest has moved to partially nanocrystalline samples which present higher values of magnetization than the amorphous ones.…”

Amorphization of Co-base alloy by mechanical alloying

“…It does not occur in some cases, however, when alloying or the formation of a solid solution is necessary before amorphization [6]. Different authors have demonstrated the effectiveness of MA to promote the amorphization of different alloys, such as Co-Nb [7], Co-B-Si [8], Co-Fe-Si-B [9], and Co-B [10].…”

“…Other authors [11] associated the amorphization with modification of the mill parameters, such as the ball-to-powder ratio, the charge volume or the milling time. Previous studies [12] demonstrated that MA is an effective method to obtain non-equilibrium phases in cobalt base alloys and helps to force the solubility and amorphization of different alloys [9,10,13].…”