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Cu nanowires covered by Ag particles is studied for potential applications in the next-generation microelectronics. To date, the deformation mechanism in the CuAg core-particle is not clear. Here, molecular dynamics simulation is used to describe the CuAg core-particle system. The results show that the equilibrium structure of Ag particles is reconstructed, when the particle ≤1.0 nm. At low temperature (1 K) indicate that three different deformation processes take part in the core-particle structure, depending on the size of Ag particles. When the particle diameter ≤2.0 nm, the prevailing deformation mechanism is the emission of dislocations from the Cu surface. For the particle diameters ranging from 3.0 to 6.0 nm, the emission of misfit dislocations from the AgCu interface is the dominant deformation mechanism. If the Ag particle ≥6.0 nm, the deformation mechanism can be characterized by the slip band, consisting of the dislocations and amorphous atoms. For elevated temperatures (2–400 K), the mechanical properties of the AgCu core-shell system are nearly independent of temperature, whereas the structure with particles larger than 2.0 nm showed a strong dependence of its mechanical properties on temperature. Based on the results, the diameter-temperature plastic deformation map is proposed.

The structure of A–C type intervariant interface in nonmodulated martensite in the Ni54Mn25Ga21alloy was studied using high resolution transmission electron microscopy. The A–C interface is between the martensitic variants A and C, each of which has a nanoscale substructure of twin-related lamellae. According to their different thicknesses, the nanoscale lamellae in each variant can be classified into major and minor lamellae. It is the boundaries between these lamellae in different variants that constitute the A–C interface, which is thus composed of major–major, minor–minor, and major–minor lamellar boundaries. The volume fraction of the minor lamellae, λ, plays an important role in the structure of A–C interfaces. For major–major and minor–minor lamellar boundaries, they are symmetrical or asymmetrical tilt boundaries; for major–minor boundary, as λ increases, it changes from a symmetrical tilt boundary to two asymmetrical microfacets. Moreover, both lattice and misfit dislocations were observed in the A–C interfaces. On the basis of experimental observations and dislocation theory, we explain how different morphologies of the A–C interface are formed and describe the formation process of the A–C interfaces from λ ≈ 0 to λ ≈ 0.5 in terms of dislocation–boundary interaction, and we infer that low density of interfacial dislocations would lead to high mobility of the A–C interface.

Commercial finite element modeling software ANSYS was used to calculate the stress and deformation distributions of crawler frame of the Rotary drill bits under turning work condition. By using finite element method, the weak points of the crawler frame can be found and the strength of the model can be calculated quickly and correctly. The results show that the crawler frame has enough strength to support the machine to finish the turning process and the maximum displacement distributed in the middle of the crawler frame. This paper will supply references for the structural optimize design of crawler frame of the rotary drill bits.

The most common tunings for the TMD in the field of vibration suppression are H∞ and H2. However, regenerative machine tool chatter is a complex problem with many variations, which therefore requires a new tuning for the optimum chatter suppression. The real part based tuning is investigated numerically by employing the minimax numerical approach, which aims to maximize the minimum real part of the primary structure under the harmonic excitation. The performances of multiple TMDs system are discussed. A face milling case is employed to verify the benefits of multiple TMDs in increasing the chatter free depth of cut. It is concluded that multiple TMDs configuration are more effective than single TMD in chatter control.

In this paper, polystyrene (PS) opals template, opal with a closed-packed face centered cubic (fcc) lattice, was prepared using vertical deposition method. The template provided void space for infiltration of Nb2O5 etc. PS colloidal nanospheres was face-centered-cubic (FCC) structure with its (111) planes parallel to the substrate. Finally, the transfer matrix method (TMM) was used to calculate photonic band-gap of PS opal and Nb2O5 inverse opal structure. The calculation results show that the photonic band-gap of Nb2O5 with inverse opal structure is wider than that of PS opals.

The theoretical and experimental studies of statistical evaluation method for flatness error are conducted thoroughly, and evaluation parameters and corresponding practicable data processing model are provided. Furthermore, a large number of experiments have been done and statistical analysis has been conducted. The results show that the distribution of extract elements of almost 90 percent of the measured planes is accordant with censored normal distribution, which proves that statistical flatness error obeys normal distribution. The characteristic that sample points are random variables is taken full advantage of in the statistic method, and the flatness error can be calculated without the influence of gross error and therefore the rate of waste parts can be reduced effectively.

The Ti6Al4V composites reinforced with Chinese SiC fiber was manufactured and then thermally exposed at 800°C, 900°C and 1000°C, respectively, for up to 500h. The interfacial reaction products were identified as TiC between Ti6Al4V and the C-coating of the SiC fiber. However, if the SiC fiber has no C-coating, the interfacial reaction forms TiC, Ti3SiC2, Ti5Si3(Cx) and Ti3Si(Cx). The thickness of the interfacial reaction zone was measured and it is found that the thickening rate is slower in the samples in which the SiC fiber has the C-coating. The growth of the interfacial reaction products is diffusion-controlled and the parameters of the growth kinetics, k0 and Q, were determined, respectively. The profile of the element distribution was calculated according to the diffusion theory and is well consistent with the expeimental data.