Graphene nanoplatelets (GNPs)-reinforced titanium matrix composites (GNPs/Ti) have been found in extensive applications in aerospace and deep-sea industries, owing to their exceptional properties, including low density, high specific strength, and superior plasticity. GNPs are often incorporated into titanium matrix composites because of their excellent properties. GNPs/Ti matrix composites have strong deformation resistance at room temperature and need to be manufactured at high temperatures. However, high temperatures could result in an interfacial reaction between Ti and GNPs, forming large TiC particles and damaging the GNPs structure, hindering the enhancement effect. Therefore, controlling the interface reaction is crucial for addressing these challenges. This study thoroughly explores existing literature on GNPs/Ti matrix composites, focusing on preparation techniques, interface structure, and interface management. At the same time, the properties of some graphene nanoplatelets or the borides nanowires-reinforced metal matrix composites are also analyzed. It particularly emphasizes challenges in interface control, encompassing the surface modification of GNPs and its effects on microstructure and mechanical properties, control of the interface reaction, and the structure design of a 3D network interface and its effects on mechanical properties. Currently, optimizing the performance of GNPs/Ti matrix composites remains elusive. However, by improving the preparation method, modifying the surface of graphene, controlling the interface reaction and adjusting the interface structure, the interface characteristics can be improved, thereby improving the performance of GNPs/Ti composites.

To investigate the thermal stability of a shot-peened specimen and ensure the reliability operation under high temperatures, CNT/Al-Cu-Mg composites were treated by shot peening (SP) and the isothermal aging treatment. The heating temperatures were 100, 150, 200, and 250 °C. Changes in surface residual stress and the distribution along the depth were investigated. The microstructure changes were analyzed by XRD and observed by TEM. Changes in mechanical properties were characterized by microhardness. The results show that the compressive residual stress (CRS) release and the microstructure changes mainly occurred at the initial stage of heating treatment. After 128 min of isothermal aging treatment at 250 °C, the surface CRS released 91.9% and the maximum CRS released 80.9%, the surface domain size increased by 222%, and the microstrain and microhardness decreased by 49% and 27.3%, respectively. The reinforcement effect introduced by SP basically disappeared. A large number of second-phase particles, such as CNT, Al₂Cu, and Al₄C₃, were anchored at grain boundaries, hindering dislocation movement and enhancing the thermal stability of the material. Isothermal aging treatment at 100 °C and 150 °C for a duration of 32 min is a reliable circumstance for maintaining SP reinforcement.

The effects of different heat treatment regimes on the microstructure and corrosion behavior of selectively laser melted (SLM) Corrax (CX) stainless steel were systematically investigated. Three distinct thermal processing approaches solution treatment (ST), aging treatment (AT), and combined solution aging treatment (ST + AT) were comparatively examined to assess their microstructural evolution and corrosion performance. The results demonstrated that the SLM-processed CX sample initially consisted of martensite and retained austenite. After solution treatment at 900 °C for 0.5 h, microsegregation was eliminated, and the retained austenite fully transformed into martensite. During direct aging at 525 °C for 3 h (AT), a portion of the martensite reverted to austenite, accompanied by grain refinement that reduced the average grain size to 1.79 μm. When the CX was solution-aged at 900 °C for 0.5 h and then 525 °C for 4 h (ST + AT), the retained austenite transformed completely into martensite. The results of potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) revealed that the aged specimen demonstrated comparatively superior corrosion resistance with reduced surface accumulation of corrosion products relative to both ST and ST + AT specimens. The electrochemical test results indicate that the selection of heat treatment parameters has a significant impact on the corrosion resistance of SLM-formed CX samples. Compared to ST and ST + AT, the corrosion performance of AT-treated samples is improved to a certain extent, with the highest E_pit (322 mV) and the largest ΔE (742). The corrosion potential is relatively high (E_corr, −414 mV vs. SCE), and the corrosion current density is relatively low (I_corr, 0.405 μA·cm⁻²). This indicates that the AT samples exhibit good corrosion resistance.

The microstructural evolution and strain-hardening mechanisms of a serviced 304 stainless steel during tensile deformation are investigated using quasi in situ EBSD measurements. This steel exhibits a high ultimate tensile strength of about 652 MPa alongside an exceptional fracture elongation of 83.4%. Its strain hardening behavior can be divided into three distinct stages. Deformation induces heterogeneous lattice rotation, which is dominated by the preferential activation of slip systems with the top two Schmid factors. With increasing strain, the deformation mechanism evolves sequentially from dislocation slip to mechanical twinning and then strain-induced martensite transformation. Mechanical twins act as the preferential nucleation sites for strain-induced martensite. In the latter two deformation stages, mechanical twinning serves as the primary driver of strain hardening, while strain-induced martensite merely contributes auxiliary hardening due to its limited volume fraction. This work elucidates the full-chain deformation mechanism of serviced 304 stainless steel. It provides experimental fundamentals for evaluating the residual ductility and failure risk of serviced austenitic stainless steel components.

To address severe wear of tunnel boring machines cutter rings under complex service conditions, a Ni-WC coating (60 wt% WC) was prepared on cutter rings by laser cladding. The results indicated that the formation of WC, W ₂ C, and M ₂₃ C ₆ hard phases in the coating increased its microhardness by 2.90 times that of the substrate. The coating exhibited a charge transfer resistance ( R _ct ) of 8.396 × 10 ³ Ω·cm ² , nearly one order of magnitude higher than that of the substrate, indicating significantly improved corrosion resistance. The tribological performance is investigated and compared under dry, groundwater, and 3.5% NaCl environments. In the dry environment, the coating surface exhibited the most severe wear, and the wear mechanism involved abrasive, fatigue, oxidation, adhesive wear, and slight spalling. By contrast, in the groundwater environment, owing to the combined effects of water film lubrication and the formation of a protective lubricating friction film composed of CaCO ₃ and Mg(OH) ₂ , only shallow scratches and minor fatigue cracks are observed on the worn surface. In the 3.5% NaCl environment, Cl ^– ions penetrate the micro-pores to initiate pitting and accelerate crack propagation, ultimately leading to severe spalling of the coating surface.