IntroductionThe raised interest in amorphous solids prepared on the base of ferroelectric materials is caused, on the one hand, by the novelty of the problem and the opportunity of manufacturing new materials with unusual properties, and on the other hand, by potential opportunities of their application in science and engineering. A major question stimulating the study of this type of material is whether the spontaneous arising of the ferroelectric state in homogeneous glass-like materials is possible and how disturbances of the long-range, average-range and short-range order in the arrangement of atoms have an influence on the physical properties of this class of materials [1,2].The possibility of spontaneous dipolar ordering in bulk amorphous materials prepared on the base of polar dielectrics was theoretically predicted by Lines [3]. According to his model, with great probability one could expect a transition to the macroscopic polar state in those amorphous materials that were prepared by rapid melt quenching of many-axes ferroelectrics, having a high value of spontaneous polarization, for example in PbTiO 3 . But till now there are no experimental works, in which the Lines theory would be reliably enough and unequivocally confirmed, in spite of the fact that there exists a number of works, in which P-E hysteresis loops and a peak of the dielectric permittivity at a temperature of the ferroelectric phase transition were observed in thin amorphous films deposited from ferroelectric LiNbO 3 [4] and PbZr 0.51 Ti 0.49 O 3 [5] targets. Despite the polarizing and dielectric properties found in these amorphous materials, one ought to remember that

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Purpose In this paper, a lifetime estimation model for the solder joint is proposed which is capable of considering both severe and running mechanical shocks which is the real case in electric converters in the automotive and aerospace applications. This paper aims to asses the reliability of the solder joint under mixed exposure of mechanical loads. Design/methodology/approach Mechanical failure process may put at risk the perfect performance of any kinds of electronic systems regardless of the applications they are prepared for. Observation of solder joint health in an electronic assembly under simultaneous exposure of severe and running shocks is an open problem. Three commonly used soldering compositions are considered while the electronic assembly is exposed to three well-known driving cycles. Findings The results show that the best performance is achieved using SAC405 soldering alloy in comparison with Sn63Pb37 and SAC387 solder alloy. Consideration of mixed exposure to the mechanical loads leads to much more accurate lifetime estimation of the solder joint in the electronic assemblies. Originality/value The originality of the paper is confirmed.

Maximizing the structural rejuvenation and ductility is one of the most heated debates in the field of metallic glasses (MGs). In this work, molecular dynamics (MD) simulation was implemented to model the ion irradiation effects on the Cu60Zr40 MG with different thermal histories and varied structural heterogeneities. The initial results indicated that the performance of an annealing-quench treatment on the MG induces the atomic configurations with different heterogeneities and potential energy values. The subsequent ion irradiation process also demonstrated that an optimized atomic structure was occurred for achieving maximum rejuvenation and ductility in the CuZr glassy alloy. It was unveiled that the intermediate initial heterogeneity provides an efficient pathway for maximizing the atomic rearrangements under the ion irradiation. It was also suggested that the medium population of Cu-centered clusters in the initial state facilitated the atomic rearrangements during the ion irradiation process. The structural characteristics and atomic reconfigurations for attaining the optimum ductility is discussed in details.