Nickel base superalloys are widely used to manufacture turbine blades, and overheating poses a serious threat to the safe service of turbine blades. In this study, a second-generation nickel base single crystal superalloy was taken as the research object, and we carried out the overheating treatment at 1100 °C and 1300 °C, and then tested the creep properties at 1000 °C/300 MPa and 1100 °C/130 MPa. Through systematic analysis of creep properties, γ/γ’ phases, and creep voids, the effects of overheating on the microstructures and creep properties of the experimental superalloy were revealed. The results demonstrate that the effect of overheating at 1100 °C on the microstructure of the experimental superalloy can be ignored, and the effect on the creep property is limited. The degree of γ’ dissolution is gradually increased and the creep property is reduced with overheating time extending at the overheating temperature of 1300 °C.

A heterostructure α-Fe₂O₃/SiC (FS) was designed by depositing α-Fe₂O₃ nanotubes on the surface of SiC through a facile hydrothermal method. Microstructure and photocatalytic activity of the hybrid were analyzed via various characterization techniques including XRD, TEM, UV–Vis DRS, PL, XPS, and electrochemical tests. The photocatalytic efficiencies of the α-Fe₂O₃/SiC heterojunction, individual SiC, and α-Fe₂O₃ were evaluated by measuring photo-Fenton degradation and photocatalytic hydrogen production. The FS hybrid exhibited a much higher photocatalytic efficiency than the individual ones. The results revealed that the cooperation of α-Fe₂O₃ and SiC led to synergy effects of the two separate semiconductors. The photocatalytic enhancement can be attributed to the strong light-harvesting capability, close contact interface, improved dispersion and predominant (104) active facet exposure of α-Fe₂O₃, as well as efficient electron-hole transfer and separation. The photocatalytic mechanism analysis reveals that the charge-carrier transportation of the α-Fe₂O₃/SiC heterojunction follows a direct Z-scheme preserving the high-energy electrons and holes. Graphical Abstract The photocatalytic charge-carrier transportation of the constructed α-Fe₂O₃/SiC heterojunction follows a direct Z-scheme preserving the high-energy electrons and holes.

In deep space exploration the exploration equipment will inevitably experience the harsh environment of cryogenic temperature. Solder joints belong to the most vulnerable parts of electronic equipment, and the harsh environment of extreme cryogenic temperature will seriously threaten the reliability of solder joints. In this paper, Sn3.0Ag0.5Cu/Cu solder joints were prepared and stored at cryogenic temperatures (−50 °C, −100 °C, and −196 °C) for up to 960 h, whilst studying the microstructural evolution and deterioration of shear properties. The results showed that the influence of cryogenic temperature on microstructure deterioration was greater than that of storage time. With the decrease of storage temperature and the extension of storage time, the Ag₃Sn intermetallic compounds (IMCs) were uniformly dispersed in the β-Sn matrix; the size decreased and the number increased. After being stored at −196 °C for 960 h, some microcracks appeared at the interface of the solder joints. Meanwhile, the shear force of the solder joints was reduced by 19.02%, and the fracture mode changed from ductile fracture to ductile–brittle mixed fracture. Therefore, it is of great scientific significance to reveal the microstructural evolution and deterioration of shear properties of the solder joints under long-term storage at cryogenic temperatures.

A Ti-based metallic glass matrix composite (MGMC), which contains abundant primary α′ and ω phases in dendrites, has a strong work-hardening ability. A significant martensitic transformation occurred during plastic deformation at 298 K, and deformation twins were produced at 77 K. Transformation-induced plasticity and twinning-induced plasticity enable MGMC to achieve prominent strength–plasticity synergy. At 298 K, the alloy exhibits a yield strength (YS) of 1140 MPa and a uniform elongation (UE) of 8.1%, while at 77 K, the YS increases to 1520 MPa, still maintaining a UE of 4.6%. The prediction models of the temperature dependent YS and martensite trigger stress $({\sigma }_{SIM})$ in MGMC were established. The strengthening and toughening mechanisms provide a great theoretical guidance for the development of low-temperature high-performance MGMCs.