The damage induced by oxidation and stress during the service process of Cr35Ni45Nb alloy and their influences on the microstructure evolution and creep rupture life of this alloy were studied. Continuity, compactness, and high temperature stability of the oxide layers are conductive to the performance of the alloy. A slight but complete layer of oxidation on surface improves the creep rupture life of the specimens. However, being exposed to long-term oxidation is observed to be counter-productive. Temperature stress generated during the air-cooling process creates large carbides near the surface of the specimen's cracks. Moreover, tiny carbides are precipitated from γ matrix and interfacial defects due to creep stress, but strip carbides are dissolved due to creep stress and the Gibbs–Thomson effect.

Novel porous Yb3Al5O12 ceramics are successfully fabricated via a green and simple foam-gelcasting approach. Using a nontoxic water-soluble copolymer of isobutylene and maleic anhydride (Isobam), together with a surfactant EMAL TD (Surf-E), 50 vol% solid loading Yb3Al5O12 aqueous ceramic slurries are prepared. Thanks to the small contents of organic additives (0.4 wt% Isobam and 1 vol% Surf-E) added, low linear shrinkage (∼13.9%), and mass loss (∼2.21 wt%) are obtained after pressureless sintering of gelcasted green body at 1600 °C for 4 h under an air atmosphere. Furthermore, porous Yb3Al5O12 ceramics with controlled porosity and spherical-like cells possess excellent structural and shape stability. The flexural strength and compressive strength of the as-prepared porous Yb3Al5O12 ceramics with a relative density of 20% remain as high as 6.3 and 19.7 MPa, respectively, and the gas permeability can be tuned between 4.3 × 10−13 and 7.8 × 10−11 m2 with exponentially increasing porosity from 58% to 84%.

The polycrystalline Nd3+-doped rare earth orthotantalate LuTaO4 was synthesized with high temperature solid-state reaction method, and the structure was determined by applying the Rietveld refinement to its x-ray diffraction. Also, the emission and excitation spectra at 7.6 K have been analyzed. The free-ions and crystal-field parameters were fitted to the experimental energy levels with the root mean square deviation of 14.6 cm−1. According to the crystal-field calculations, 152 Stark energy levels of Nd3+ were assigned. Finally, the fitting results of free-ions and crystal-field parameters were compared with those already reported for Nd3+:YAlO3. The results indicate that the free-ions parameters are similar to those of the Nd3+ in LuTaO4 and YAlO3 hosts except for the values of two-body electrostatic parameter γ, and the 2-rank crystal-field parameters of two hosts have relatively large differences while other crystal-field parameters have been similar to each other. Moreover, the crystal-field interaction of Nd3+ in LuTaO4 is stronger than that in YAlO3.

A novel synchronous rolling-casting for metal (SRCM) process for producing metal components is developed. In this paper, the microstructure evolution and mechanical property of ZLl04 alloy with different pouring temperatures by SRCM are investigated. In the process, the pouring temperature has great effects on the microstructure and mechanical property primarily through the crystal change in the rolling-casting area. Temperature of liquids and solids of ZL104 alloy is measured by differential scanning calorimetry. Distribution and characteristics of the microstructure of samples are examined by optical microscopy, scanning electron microscopy equipped with energy dispersive spectrometer. The results show that the samples fabricated by SRCM present uniform structure and good performance with the pouring temperature at 620 °C when the velocity of the substrate is at 10 cm/s. The tensile strength of ZLl04 alloy reaches 211.89 Mpa, while the average vickers hardness is 81.5 HV.

Different volume fractions (0.5–4.5 vol%) of carbon nanotubes (CNTs) were used to reinforce a binary Fe50Co soft magnetic alloy. The first method for dispersion involved dry mixing and ball milling of the powder, while the second included wet mixing in dimethylformamide under ultrasonic agitation, drying and then dry ball milling. The powders were consolidated using spark plasma sintering. Tensile test and SEM analyses were performed to characterize the mechanical properties and the fracture surface of the sintered materials. The best magnetic and mechanical properties were achieved using the first method. A maximum enhancement in tensile strength of around 20% was observed in the 0.5 vol% CNT composite with improved elongation compared to the monolithic Fe50Co alloy. In addition, the magnetic properties were enhanced by adding CNTs up to 1 vol%, and an improvement in densification was observed in composites up to 1.5 vol% CNT with respect to monolithic Fe50Co alloy.

The ground state properties of Fe3−x Crx O4 (x = 0–3) compounds were studied using first principles calculation. Stress–strain methods were used to evaluate elastic constants of these compounds. These compounds are mechanically stable structures, because they satisfy the mechanical stability criteria. The mechanical moduli were estimated using the Voigt–Reuss–Hill approximation. The calculated bulk moduli of Fe3O4, Fe2CrO4, FeCr2O4, and Cr3O4 are 190.9 GPa, 135.5 GPa, 180.1 GPa, and 235.6 GPa, respectively. Both of anisotropic indexes and 3-D surface contour were used to illustrate the elastic anisotropy. Debye temperature and anisotropy of acoustic velocity of Fe3−x Crx O4 compounds were also investigated. The maximum Debye temperature is attributing to Cr3O4 with 507.6 K among Fe3−x Crx O4 compounds. The minimum thermal conductivity of Fe3−x Crx O4 compounds was estimated by both Clarke's model and Cahill's model. Moreover, 3-D surface contour of the anisotropic thermal conductivity of Fe3−x Crx O4 compounds was obtained based on the Clarke's model and anisotropic Young's modulus.

The microstructure evolution of a typical nickel-based superalloy was studied in the temperature range of 960–1160 °C with the strain rate of 0.001 s−1 by using electron backscattered diffraction technique. Based on the grain orientation spread method, the dynamic recrystallization (DRX) grains were distinguished from the deformed grains. The results revealed that the volume fraction and the size of DRX grains increased with the increasing deformation temperatures. Most of the original Σ3 boundaries lost their twin characteristics due to crystal rotations during hot deformation. Meanwhile, lots of new Σ3 boundaries were formed in the DRX grains mainly by growth accidents. Moreover, the deformation temperature had a similar effect on the fraction of Σ3 boundary and the Σ3 boundary density in the DRX domains, which increased firstly and then decreased with the increasing deformation temperature. The Σ3 boundary density was analyzed as a function of grain size, and the critical grain size below which no twin forms was calculated to be 2.06 µm. In addition, the coherent Σ3 boundaries were easier to form at the higher deformation temperature due to their lower boundary energy.

A diamond film was deposited on YT14 cemented carbide cutting tools with a chemical vapor deposition, the surface-interface morphologies, compositions of chemical elements, phases, atomic bonding energies, and structures of the films were analyzed with a scanning electron microscopy, energy dispersive spectrometer, x-ray diffraction, x-ray photoelectron spectroscopy, and Raman, respectively, and the mechanical properties of the film were characterized with a nanoindentation and scratch test, respectively. The results show that the surface of diamond film is continuous and dense, the surface roughness of the film is 79.2 nm, and the average grain size is 478.2 nm. The atomic binding energies of C1s are composed of sp 2 at the Raman shift of 1363.01 cm−1 and sp 3 at the Raman shift of 1556.26 cm−1. The hardness and equivalent elastic modulus of the film is 16.27397 GPa and 166.1791 GPa, respectively, and the binding strength of the film-substrate is 26.2 N, showing a high anti-scratch ability.

The machining of shape memory alloys (SMAs) is fairly essential and integral part in the manufacture of components for utilizing in engineering applications. An effort has been made in the present work to study the effect of wire electro discharge machining process parameters such as pulse on time (Ton), pulse off time (Toff) and servo voltage (SV) have been analyzed on material removal rate and surface roughness. The investigation clearly reveals that an increased pulse on time with decrease in pulse off time as well as SV increases the amount of material removed in machining of SMAs. On the other hand, the surface roughness increases with increased pulse on time and decreases with increased pulse off time as well as SV. The surface topography of the machined surface was analyzed using scanning electron microscope (SEM) and confocal micrographs. Phase changes on the machined surface with respect to pulse on time and SV were evaluated from X-ray diffractometer (XRD) analysis.

Zinc phthalocyanine (ZnPc) thin films were prepared by pulsed laser deposition (PLD) using KrF laser (λ = 248 nm, τ = 5 ns). The effect of laser fluence (in the region from 10 to 100 mJ/cm2) and repetition rate of 50 and 200 Hz to the film growth and its properties was investigated. The growth of ZnPc thin film was in situ monitored using transmission measurement in ultraviolet-visible spectral range. The optical properties in conjunction with density functional theory/time-dependent density functional theory calculations suggested the growth of the film in β-phase. X-ray diffraction also revealed crystalline character of the film. The electrical properties analyzed by van der Pauw method exhibited resistivity ρ ≈ 108–1010 Ω cm. Fourier transform infrared spectroscopy analyses revealed low deterioration of PLD deposited ZnPc films. We demonstrate that, by finely tuning the deposition conditions, PLD is a successful technique for fabrication of ZnPc thin films.

A research was carried out to investigate the microstructures and mechanical properties of high Mn containing Al–5Mg–Mn alloys cast under near-rapid cooling. The results indicated that the mechanical properties of the hot bands and cold rolled sheets were remarkably improved with Mn content increasing to 1.6 wt%. The near-rapid cooling process greatly refined the intermetallic constituents. The intermetallic Al6(Fe,Mn) particles found in the hot bands were rare and small when the content of Mn was hypoeutectic. In the samples with higher Fe and Si content, a large amount of Al6(Fe,Mn) and Mg2Si particles remained in the hot bands. But the hot bands still showed better mechanical properties due to the refinement of the intermetallic constituents by the near-rapid cooling process. The results were of commercial interest to the production of AA5083 alloy via continuous strip casting process.

Semisolid forging is a type of semisolid metal processing with high solid fraction. However, the presence of nanosized particles has strong influences on flow behavior of the composites in the semisolid forging process. In this study, the compression deformation behavior of nanosized Al2O3 particles (Al2O3np) reinforced 7075 aluminum matrix composites with high solid fraction was investigated by conducting semisolid isothermal compression experiment. The microstructures after semisolid compression were characterized. The results showed that the true stress decreased with the increase of the deformation temperature and size of Al2O3np, the decrease of the strain rate and mass fraction of Al2O3np. After semisolid compression, deformation degree in large deformation zone was larger than that in free deformation zone. Besides, the solid grains in large deformation zone showed evidence of having undergone different degrees of plastic deformation under different deformation conditions. Simultaneously, the deformation mechanisms during the semisolid compression process were discussed.

The instability and fracture process during uniaxial tension was observed from load-stop tensile tests and finite element simulation. The results indicate that at the end of instability, the direction of the maximum principle stress near the necking groove turns to being perpendicular to the groove. This tensile stress is critical to the growth of fracture. The fracture initiates from the internal of the sheet at the center of volume where the two local necking grooves intersect. Material here is under triaxial tensile stress state and the principle stresses in all three directions are the largest. Once the initial crack occurs, it propagates along the zero-strain-rate necking groove. Moreover, the final fracture angle between the fracture plane and the tensile axis is always larger than theoretical value. An important reason is the ignorance of the triaxial stress state evolution during instability in theoretical calculation.