Mechanical and magnetic properties of metallic glasses

Simple correlation between mechanical and thermal properties in TE–TL (TE=Ti,Zr,Hf;TL=Ni,Cu) amorphous alloys

“…3 shows clearly that H v increases with x (TL) for all TEs [4,15,21,24,32,33]. Moreover, the variations of H v with x in Fig.…”

“…3. Microhardness H v of Zr-Cu [15], Zr-Ni [15], Ti-Cu [32,33], Ti-Ni [21] , Hf-Cu [33], Zr 36 Cu 64 [24] and Hf 34 Cu 66 [4] alloys vs. Cu,Ni content x. The inset: microhardness H v of the same alloys vs. E. Crossed symbols are present data and full symbols are for bulk glassy alloys.…”

Electronic structure and glass forming ability in early and late transition metal alloys

“…1 we show XRD patterns of selected Cu-Hf, Cu-Ti and Cu-Zr crystallized samples. As noted earlier [1,38], the crystallization of Cu-Hf MGs becomes more complex with increasing Cu content (which may contribute to the enhancement of GFA [17,20,21] observed at higher Cu-contents [1,16,37]). In particular, the XRD pattern of the Cu40Hf60 sample shows almost pure body centered tetragonal (bct) CuHf2 phase, whereas that of the Cu50Hf50 alloy already shows a complex mixture of bct CuHf2 and the orthorombic (o) Cu10Hf7 phase.…”

“…The atomic size mismatch, which destabilizes the crystalline lattice [15,18] and the effective valence Zeff , which is expected to stabilize the amorphous phase [19], were also proposed to correlate with GFA. We note however that there is no evidence for a correlation between Zeff and GFA [20,21]. Since the most of these criteria were designed for binary systems, they work quite well for some binary and ternary alloy systems (e.g., [16,18,20,21]), but perform less well for the more important multicomponent high-dc BMGs [14,15,22].…”

“…Further, numerical simulations are used in order to associate GFA with efficient packing of atomic clusters in MGs [25], or to test the relative importance of the various factors entering into Inoue´s rules [26]. Recent experiments with amorphous high entropy alloys a-HEA , for example [27], seemed to further complicate the problem of the origin of GFA, but more careful analysis [15,28] indicates that the stability and GFA of a-HEA alloys containing the early transition metals (TE) behave similarly to those in conventional MGs containing TEs [20,21].Recently we noted [20,29] that to our knowledge no criterion for GFA in metallic alloys takes their electronic band structure (ES) explicitly into account, in spite of the fact that in metallic systems, a large contribution to the cohesive energy comes from the…”