•The dominant crystal plane in α-Fe precipitates changes with minor Nb addition.•Such microstructural evolution can be explained by the Bravais-Friedel law.•Substitution of Nb for Fe in Fe85B10P5 alloy results in the inflexion of Hc.The influence of Nb substitution for Fe on the precipitation of α-Fe, the glass forming ability (GFA) and the magnetic properties of the (Fe85−xB10P5Nbx) (x = 0, 1, 3, 4 and 5 at.%) alloys are investigated. Based on the XRD measurement of the melt-spun ribbons, it is found that the dominant crystal plane in α-Fe precipitates gradually changes from (200) to (110) and then only broad peaks without any appreciable crystalline peaks can be observed with increasing Nb content from 0 at.% to 5 at.%. Such microstructural evolution are clarified with other elements M (M = Ni, Mo, Y, Cr and Si) addition, and can be well explained based on the Bravais-Friedel law and the negative mixing enthalpy between Nb(or M) and Fe (or B). Furthermore, the strong bonding between Nb and Fe atoms results in the formation of FeNb clusters and then enhances short-range-order clusters, leading to the enhance of GFA and decrease of coercive force from 13.82 A/m to 2.3 A/m with the addition of Nb content less than 4 at.%. With further increasing Nb content, the coercive force becomes higher, which is contributed to the formation of NbB clusters and the poor solute-solute avoidance.

•There is a favorable electron concentration (e/a) value for Fe-based amorphous formation.•Novel FeBPSn amorphous alloys with Fe content higher than 83% are prepared based on the (e/a) criterion.•Sn benefits the increase of amorphous forming ability and Bs of Fe-based amorphous alloys.The composition design for the Fe-based amorphous alloys with high Fe contents is introduced based on the Nearly-Free-Electron model, which indicates that there is a favorable electron concentration (e/a) value for amorphous formation. The FeBPSn amorphous alloys with Fe contents higher than 83% have been prepared based on the favorable (e/a) value. The influences of Sn on the amorphous forming ability (AFA) and magnetic properties are investigated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), and vibrating sample magnetometer (VSM), respectively. The results show that the inflexion of the coercive force Hc ~ (e/a) relationship is just contrary to that of the AFA ~ (e/a) relationship. The present work provides a convenient way to design Fe-based amorphous alloys with good magnetic performances by the metalloid admixture according to the favorable (e/a) value.

•Thermal stability of B2 CuZr phase was studied in CuZrTi alloys.•Microstructures of CuZrTi martensitic alloys were checked.•Martensitic transformation temperature decreases with increasing Ti content.•Martensitic transformation in CuZr-based alloys could be of electronic nature.•Effects of thermal cycling on martensitic transformation behaviors were discussed.The effects of minor Ti addition on the thermal stability of B2 CuZr phase, the microstructure and the martensitic transformation (MT) in Cu50Zr50−xTix (x = 0, 2.5, 7.5 and 10 at%) alloys were investigated. It was found that the crystallization products, i.e. Cu10Zr7 and Cu(Ti, Zr)2, of Cu–Zr–Ti amorphous alloys transform to B2 CuZr phase at high temperatures. The corresponding eutectoid transformation temperature gradually increases with increasing Ti content, implying the decrease of the thermodynamic stability of the B2 CuZr phase. The microstructures of Cu–Zr–Ti martensitic alloys were proven to contain B2 CuZr, CuZr martensite, Cu10Zr7, Cu(Ti, Zr)2, and ZrTiCu2 crystals. Dilatometric measurements reveal that the MT temperature reduces with increasing Ti content, which would be of electronic nature. With increasing thermal cycles, the MT temperature gradually decreases while the reverse MT temperature increases, which results from the enhancement of the dislocation density, the partial decomposition of the equiatomic CuZr crystals and the partially reversible MT.

•A new parameter (Sσ/kB)/M is proposed to predict the glass-forming ability of metallic glasses, where M and Sσ/kB are the fragility of the superheated melts and the mismatch entropy, respectively.•Bulk metallic glasses (BMGs) exhibit (Sσ/kB)/M values larger than 0.17.•It is more likely to form BMGs for the eutectic alloys with a mismatch entropy larger than 0.17, as the values of M for alloys are near 1.Based on the thermodynamic fragility model, a new parameter (Sσ/kB)/M is proposed to evaluate the glass-forming ability (GFA) of metallic glasses, where M and Sσ/kB are the fragility of the superheated melts and the mismatch entropy normalized by the Boltzmann constant, respectively. A positive relationship between (Sσ/kB)/M and glass forming ability is observed for both bulk metallic glasses and marginal metallic glasses, and an eutectic alloy with (Sσ/kB)/M larger than 0.17 can be selected as a bulk glassy forming candidate. As most alloys can obtain the temperature dependence of viscosity above liquidus temperature, (Sσ/kB)/M can be used as a prediction parameter for high GFA. Although both high and low M values can work in determining GFA, the high GFA of bulk metallic glasses is primarily due to the large mismatch entropy (Sσ/kB>0.17).In this figure, it can be seen that the proposed parameter (Sσ/kB)/M=0.17 and the reduced glass transition temperature Trx=0.53 split BMGs and MMGs into different ranges. Since the value of M for metallic glasses is approximately equal to 1, it is more likely to form BMGs for the eutectic alloys with a mismatch entropy larger than 0.17. This assumption has been approved in 38 kinds of metallic glasses in this manuscript.

Molecular dynamics (MD) simulations based upon embedded atom method (EAM) potential are employed to explore the structural stability of ultrathin Ni nanowires. The configurations of Ni nanowires with different structure characterized as (m, n) and FCC <1 1 0> are constructed firstly, and then they are suffered from a static relaxation to reach a stable state. The results show that the structures of (4, 2), (5, 3), (5, 4) and (7, 6) are unstable, prone to convert to another structure after static relaxation; furthermore, the non-helical structures (5, 5), (6, 6) and FCC <1 1 0> structures show lower structural energy compared with helical structures (3, 2), (6, 4) and (7, 5) etc.

Based on the dense gas-like model of viscosity and Born–Green viscosity formula, the modification of Lennard–Jones (LJ) potential has been done to make it suitable to describe the properties of liquid Al. Experimental data involving viscosity and pair correlation function (PCF) of liquid Al are used to derive the potential parameters. The structural properties and dynamical heterogeneity of liquid Al in cooling processes have been studied via molecular dynamics simulations to test the accuracy of new pair potential. Calculated results are comparable with those derived by Mei’s embedded-atom method (EAM), exhibiting correct trends as a function of temperature.