Zhaozhi Wu

In the context of high-temperature working conditions, the surface of H13 alloy steel exhibits a propensity for high-temperature erosion and wear. The advent of laser cladding repair technology has led to significant advancements in the field of surface restoration. Nevertheless, laser cladding repair may result in microcracks on the repaired surface. To solve this problem, an innovative approach to enhancing the surface integrity of molds through the application of laser shock peening was explored. This method aims to address surface imperfections by introducing residual compressive stress. The microhardness increased from 443 HV1.5 to 605 HV1.5. Residual compressive stress of −158 MPa was introduced. The surface corrosion resistance and wear performance were enhanced after laser shock peening. The corrosion current density was reduced, and the polarization resistance was increased.

Micro-electrochemical machining (micro-ECM) is a non-contact subtractive process in which material is removed by anodic dissolution. This review examines 150 publications from 1992 to 2026 on hybrid and assisted machining, tool electrode design and fabrication, and electrolyte flow control. The literature was drawn from major scientific databases and includes journal articles, conference papers, and book chapters, with an emphasis on precision machining of difficult-to-machine materials. In contrast to previous reviews, this work compares the reported performance ranges, limitations, and application scenarios of five principal micro-ECM strategies: vibration-assisted, laser-assisted, jet-based, magnetic-field-assisted, and through-mask machining. It also evaluates tool electrode materials, structural designs, and fabrication methods, including abnormal wear mechanisms in silicon electrodes. Different electrolyte systems and approaches to controlling the inter-electrode flow field are discussed. The review highlights unresolved challenges, including limited understanding of multiphysics interactions, the trade-off between machining localization and mass transport, wear of non-metallic conductive electrodes, and the limited maturity of industrial applications. Priorities for future research include multiscale modeling, in situ measurement, closed-loop process control, and the development of more sustainable electrolytes. These insights may support further advances in micro-ECM and its industrial implementation.

Electrochemical machining is widely recognized as a high-efficiency, low-cost and high-precision non-traditional machining technology for the manufacturing of turbine blade components. Nevertheless, in the practical electrochemical machining of turbine blades, the uneven spatial distribution of electric field intensity within the inter-electrode machining gap inevitably causes inconsistent anodic dissolution, which significantly deteriorates the final surface quality of machined blades. A set of comparative machining experiments were conducted on Inconel 625 superalloy. The experimental results fully verified that pulsed current machining could effectively improve the surface integrity and surface quality, and the optimal matching electrical parameters were successfully determined through systematic data analysis. The essential improvement mechanism lied in the effective suppression of stray current-induced scattered dissolution under pulsed power supply, which was highly consistent with the numerical simulation conclusions.

The advanced manufacturing of metal micro-holes is of great significance in various fields of industrial production, including aerospace, automotive, electronics, and healthcare. New technologies are constantly emerging, including various multi-energy field manufacturing technologies, and the knowledge system is complex and intricate. The present article summarizes recent advancements in metal micro-hole manufacturing technologies, drawing parallels with existing laser processing and electrochemical processing technologies. The present systematic review has been conducted with the objective of providing a comprehensive overview of the latest methodologies. The present review paper is of particular significance in that it encompasses not only the fundamental principles and innovative process methods, but also the most recent research progress and current problems. Furthermore, a synopsis of the developmental trajectory of advanced sustainable manufacturing technology for micro-holes was furnished.

This work reports on a systematic investigation of the microstructure and comprehensive performance of Cu–Fe immiscible composite coatings prepared through the combination of mechanical alloying and laser cladding. The samples were characterized by scanning electron microscopy with an energy dispersive analysis, X-ray diffraction, a digital microhardness tester, a current tester, an electrochemical analyzer, and a magnetometer. The results show that the immiscible composite coatings are mainly composed of α-Fe particle dispersion in the ε-Cu matrix due to liquid phase separation, and this is exacerbated by the addition of more Fe content. Concentrated distribution of Fe-rich particles at either the top or bottom of the immiscible composite coatings is driven by the dominant mechanism of Marangoni and Stokes motion. With the increased fraction of Fe content, the microhardness and electrical resistivity increased, but with a degradation in corrosion resistance. With the increased ball milling time, the electrical resistivity increased, and the corrosion resistance improved. Compared to the medium-carbon steel substrate, the immiscible composite coatings can achieve an improved corrosion resistance, as well as a maximum saturated magnetization of 10.172 emu/g and the lowest coercivity at 17.249 Oe.

This work reports on systematic investigation of the microstructure and comprehensive performances of Cu–Fe immiscible composite coatings prepared through the combination of mechanical alloying and laser cladding. The samples were characterized by scanning electron microscopy with an energy dispersive analysis, X-ray diffraction, a digital microhardness tester, current tester, electrochemical analyzer and magnetometer. Results show that the immiscible composite coatings are mainly composed of α-Fe particles dispersion in the ε-Cu matrix due to liquid phase separation, and this is exacerbated in addition of more Fe contents. Concentrated distribution of Fe–rich particles at either the top or bottom of the immiscible composite coatings are driven by the dominant mechanism of Marangoni and Stokes motion. With the increased fraction of Fe content, the microhardness and electrical resistivity increased, but a degradation in corrosion resistance. With the increased ball milling time, the electrical resistivity increased and the corrosion resistance is improved. Compared to the medium-carbon steel substrate, the immiscible composite coatings can achieve an improved corrosion resistance, as well as a maximum saturated magnetization of 10.172 emu/g and lowest coercivity of 17.249 Oe.

Bioreactors are crucial for biopharmaceutical engineering, and their properties have an important impact on cell cultivation. Orbitally shaken bioreactors (OSRs) are gradually gaining more and more attention because of their special operational advantages and suitability for disposable cultivation. In this paper, the performance of OSRs is analyzed in comparison to stirred tank bioreactors (STRs). CFD models were established to investigate the difference in fluid dynamics between OSRs and STRs at the same power input levels. The CFD and experiment data showed that mixing and oxygen transfer needed less energy in OSRs than in STRs. Moreover, the shear stress was still at a low level for agitation behaviors in both OSRs and STRs.

Functional wetting surfaces have excellent prospects in applications including self-cleaning, anti-fog, anti-icing, corrosion resistance, droplet control, and friction power generation. Laser micromachining technology is an advanced method for preparing such functional surfaces with high efficiency and quality. To fully exploit the potential of laser micromachining and the related hybrid methods, a wide spectrum of knowledge is needed. The present review systematically discusses the process capabilities and research developments of laser micromachining and its hybrid methods considering the research both in basic and practical fields. This paper outlines the relevant literature, summarizes the characteristics of functional wetting surfaces and also the basic scientific requirements for laser micromachining technology. Finally, the challenges and potential applications of superhydrophobic and superoleophobic surface are briefly discussed. This review fills the gap in the research literature by presenting an extended literature source with a wide coverage of recent developments.