Ultrahigh-temperature ceramic matrix composites are currently among the most promising high-temperature-resistant materials, owing to their high-temperature strength, high-toughness and excellent corrosion resistance; they are widely used in national defense and aerospace fields. However, it is a difficult material to machine, and high precision is difficult to achieve using traditional machining methods. Nontraditional machining methods are not constrained by material physical and mechanical properties, and good surface quality is easily obtained, which is an important direction in the field of ultrahigh-temperature ceramic matrix composites. This paper summarizes the recent nontraditional machining methods utilized in the fabrication of ultrahigh-temperature ceramic matrix composites. Firstly, various nontraditional machining methods for ultrahigh-temperature ceramic matrix composites based on borides, carbides and nitrides are reviewed, and the machining performances under different machining conditions are compared. Subsequently, the problems and challenges of ultrahigh-temperature ceramic matrix composite nontraditional machining are summarized and discussed. Lastly, the future development path of nontraditional machining methods for ultrahigh-temperature ceramic matrix composites is summarized and predicted.

An ultra-narrow precision slit with a width of less than ten micrometers is the key structure of some optical components, but the fabrication of these structures is still very difficult to accomplish. To fabricate these slits, this paper proposed a periodically reducing current over-growth electroforming process. In the periodically reducing current over-growth electroforming, the electric current applied to the electrodeposition process is periodically stepped down rather than being constant. Simulations and experimentation studies were carried out to verify the feasibility of the proposed process, and further optimization of process parameters was implemented experimentally to achieve the desired ultra-narrow precision slits. The current values were: $I_1=I_{initial}, I_2=0.75I_{initial} at Q_c=0.5Q_t, I_3=0.5I_{initial} at Q_c=0.75Q_t,\mathrm{r}\mathrm{e}\mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}\mathrm{t}\mathrm{i}\mathrm{v}\mathrm{e}\mathrm{l}\mathrm{y}.$It was shown that, compared with conventional constant current over-growth electroforming, the proposed process can significantly improve the surface quality and geometrical accuracy of the fabricated slits and can markedly enhance the achievement of the formed ultra-narrow slits. With the proposed process, slits with a width of down to 5 ± 0.1 μm and a surface roughness of less than 62.8 nm can be easily achieved. This can improve the determination sensitivity and linear range of the calibration curves of spectral imagers and food and chemical analysis instruments. Periodically reducing current over-growth electroforming is effective and advantageous in fabricating ultra-narrow precision slits.

During the process of internal cylindrical ultrasonic-assisted electrochemical grinding (ICUAECG), both the workpiece and the conductive grinding wheel are rotating, the machining space is closed and narrow, the electrolyte is difficult to spray into the machining area, and the insulation between the workpiece and the machine bed is challenging. According to the machining characteristics of ICUAECG, the structure of a special machine tool was designed to mitigate these problems. In particular, the rotation, electrolyte supply, electric connection, and insulation modes of the workpiece clamping parts were studied, yielding a novel workpiece clamping- and rotating-device design. This structure can fully use the internal space of the hollow spindle of the machine tool, effectively reduce the external moving parts, and achieve the appropriate liquid injection angle of the electrolyte. The ultrasonic vibration system and its installation mechanism, the dressing device of the conductive grinding wheel, and the electric grinding spindle-mounting and -fixing device were analyzed in detail. Then, a special machine tool for ICUAECG was designed, the operability and feasibility of which were verified by experiments involving conductive grinding wheel dressing and ICUAECG.

The extreme thermal loads encountered in fourth-generation synchrotron radiation sources and X-ray free-electron lasers (XFEL) impose stringent requirements on X-ray optical components. Conventional materials such as beryllium and silicon increasingly exhibit limitations under high-energy conditions, including insufficient thermal conductivity, limited radiation stability, and significant absorption losses, rendering them inadequate for next-generation high-energy X-ray optics. In this context, single-crystal diamond, with its high thermal conductivity, low absorption coefficient, and excellent mechanical strength and radiation resistance, has emerged as a promising candidate for high-energy X-ray refractive optics. This review systematically summarizes recent advances in the fabrication and performance optimization of diamond X-ray refractive lenses for high-energy applications. Starting from the evolving demands of modern synchrotron radiation facilities and XFEL, the fundamental requirements for materials and structural design in high-energy X-ray optics are analyzed. Through comparisons with representative materials, the advantages of diamond in thermal management and transmission performance are highlighted. Major micro- and nanofabrication techniques, including femtosecond laser processing, focused ion beam milling, and plasma etching, are comprehensively reviewed, with emphasis on their respective characteristics in terms of processing efficiency, precision control, and damage introduction. The emerging trend of hybrid fabrication strategies is also discussed. Furthermore, the effects of surface roughness, subsurface damage, and crystal defects on wavefront quality and focusing performance are examined, along with corresponding post-processing and surface correction methods. Finally, current challenges related to large-size single-crystal growth, high-precision low-damage fabrication, and long-term operational stability are discussed, and future development directions for diamond-based X-ray refractive optical components are outlined.

Programmable hollow metallic microdevices with lateral outlets are attractive for distributed fluid handling, but integrating an axial lumen, side channels, and a sealed distal tip remains fabrication-intensive. Here, a core-filament jet electrodeposition (CF-JED) strategy combines segmented electrolyte-jet operation with sacrificial nylon-fiber templating to fabricate multichannel nickel microtubes. An 80 μm nylon core defines the axial lumen, whereas 50 μm transverse and helical fibers prescribe lateral channels. Interrupting the jet creates the in situ assembly interval for template placement; resumed localized electrodeposition encapsulates the fibers and can close the distal tip, and physical pull-out releases the channels without chemical dissolution or drilling. Stable growth was obtained at 2.5 mA with an axial growth rate of approximately 15 μm·min⁻¹. Micro-computed tomography revealed a 50 ± 5 μm radial channel and a 76 ± 6 μm axial lumen interconnected within the sealed-tip structure. SEM/EDS confirmed open lateral apertures and nickel-rich walls, while water-immersion gas testing provided qualitative evidence of channel interconnectivity. CF-JED therefore provides a template-defined route to programmable multichannel hollow-metal microstructures; direct liquid-flow, mechanical, and biological validation remain necessary for application-specific use.

The automotive panoramic roof exhibits a large-size and thin-wall geometry, with a length-to-thickness ratio approaching the thousand level. This geometric feature makes its forming quality highly sensitive to forming conditions. During the glass molding process, variations in temperature evolution, loading, and cooling parameters may lead to residual stress accumulation and springback deformation, thereby affecting dimensional accuracy and final forming quality. In this study, a full-process finite element model was established and combined with an L16(4^5) orthogonal design to investigate the effects of five key process parameters—heating temperature, holding time, quenching air velocity, quenching air pressure, and quenching time—on the mean residual stress and mean springback displacement in the glass molding process (GMP). The results showed that, within the given parameter ranges, heating temperature, holding time, and quenching time had relatively pronounced effects on the mean residual stress; the mean residual stress was relatively low when the heating temperature was 680 °C, the holding time was 3 s, and the quenching time was 12 s. Heating temperature, quenching air velocity, and quenching time had relatively pronounced effects on the mean springback displacement; the mean springback displacement was relatively low when the heating temperature was 677.5 °C, the quenching air velocity was 13 m/s, and the quenching time was 10 s. Based on the orthogonal analysis, regression models for the mean residual stress and mean springback displacement were further developed, and parameter combinations were screened using the NSGA-III method. Experimental validation showed that the relative error of the mean residual stress was controlled within 15%, indicating that the established model could, to some extent, capture the relationship between process parameters and forming quality indicators, thereby providing guidance for precision forming and process optimization of large-scale thin-walled automotive panoramic roofs.