In situ formed two-phase metallic glass with surface fractal microstructure

Effect of the Cu and Ni content on the crystallization temperature and crystallization mechanism of La–Al–Cu(Ni) metallic glasses

“…1 The observed heat of mixing was positive when mixing the main atomic pairs (13 and 9 kJ·mol -1 when mixing the La-Zr and Zr-Gd atomic pairs, respectively), although both pairs may yield negative heat values when mixed with others (e.g., the La(Zr)-Al, La(Zr)-Cu, La(Zr)-Ni atomic pairs, or the Zr(Gd)-Al, Zr(Gd)-Co atomic pairs). 1,3 However, the phase separation observed for La-Zr-and Zr-Gd-based alloys is stronger than that observed for the alloys with the negative heat obtained from the mixing of the main atomic pairs, and this can be detected experimentally by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). 1,3 For MG with a high glass forming ability (GFA), the heat of mixing is negative when mixing the main atomic pairs (e.g., the La-Al, La-Cu, La-Ni and La-Co atomic pairs in La-Al-Cu-Ni(Co) alloy systems) and the phase separation is weak.…”

“…Multi-step crystallization reactions in MGs can be studied by differential scanning calorimetry (DSC) and lead to distinct features in the DSC curves, particularly for MGs with an amorphous phase separation. When studying multi-composition alloys, Kündig et al 3 found that the crystallization of the La 27.5 Zr 27.5 Cu 10 Ni 10 Al 25 alloy can be described as a merging of the crystallization of the La 53. 5 Al 21.…”

NVESTIGATIONS OF MICROSTRUCTURE AND PHASE TRANSFORMATIONS OF Fe71.25Si9.5B14.25In5 ALLOY

“…One promising solution for this purpose is by the use of liquid immiscible systems [1,[3][4][5][6]. However, to utilize this feature in an optimal way, knowledge of the high-temperature characteristics of such alloys is necessary.…”

Phase separation in Ni70Nb30−Y glasses

“…The phase separation of the liquid is determined by the thermodynamic properties of the alloy system. For the phase separated metallic glasses reported in [6][7][8][9][10][11][12] the critical temperature of liquid-liquid phase separation T c is above the liquidus temperature. In this case, phase separation leads to a special microstructure with a length scale up to several microns and some self-similar features are observed by transmission electron microscopy [6,13,14].…”

“…In bulk metallic glass forming alloys the addition of elements with strong positive enthalpy leads to improvement of ductility [4] or glass forming ability [5] in a certain composition range. Phase separated metallic glasses have been prepared in several alloy systems by rapid quenching the melt : Zr-Y-Al-Ni [6], Zr-La-Al-Ni-Cu [7], Zr-Y-Co-Al [8], Ni-Nb-Y [9], Zr-Nd-Al-Co [10] , Cu-(Zr,Hf)-(Gd,Y)-Al [11], and Zr-(Ce,Pr,Nd)-Al-Ni [12]. The phase separation of the liquid is determined by the thermodynamic properties of the alloy system.…”