The high-quality, high-efficiency micro-hole drilling of structural ceramics to improve the thermal conductivity of hot-end parts or achieve high-density electronic packaging is still a technical challenge for conventional processing techniques. Recently, the laser drilling method (LDM) has become the preferred processing tool for structural ceramics, and it plays an irreplaceable role in the industrialized processing of group holes on structural ceramic surfaces. A variety of LDMs such as long pulsed laser drilling, short pulsed laser drilling, ultrafast pulsed laser drilling, liquid-assisted laser drilling, combined pulse laser drilling have been developed to achieved high-quality and high-efficiency micro-hole drilling through controlling the laser–matter interaction. This article reviews the characteristics of different LDMs and systematically compares the morphology, diameter, circularity, taper angle, cross-section, heat affect zone, recast layer, cracks, roughness, micro–nano structure, photothermal effect and photochemical reaction of the drilling. Additionally, exactly what processing parameters and ambient environments are optimal for precise and efficient laser drilling and their recent advancements were analyzed. Finally, a summary and outlook of the LDM technology are also highlighted.

Aluminum is a kind of metal that we often encounter. It can also be absorbed by the human body invisibly and will affect our bodies to a certain extent, e.g., by causing symptoms associated with Alzheimer’s disease. Therefore, the detection of aluminum is particularly important. The methods to detect metal ions include precipitation methods and electrochemical methods, which are cumbersome and costly. Fluorescence detection is a fast and sensitive method with a low cost and non-toxicity. Traditional fluorescent nanomaterials have a high cost, high toxicity, and cause harm to the human body. Graphene quantum dots are a new type of fluorescent nanomaterials with a low cost and non-toxicity that can compensate for the defects of traditional fluorescent nanomaterials. In this paper, c-GQDs and o-GQDs with good performance were prepared by a bottom-up hydrothermal method using o-phenylenediamine as a precursor and citric acid or boric acid as modulators. They have very good optical properties: o-GQDs exhibit orange fluorescence under UV irradiation, while c-GQDs exhibits cyan fluorescence. Then, different metal ions were used for ion detection, and it was found that Al³⁺ had a good quenching effect on the fluorescence of the o-GQDs. The reason for this phenomenon may be related to the strong binding of Al³⁺ ions to the N and O functional groups of the o-GQDs and the rapid chelation kinetics. During the chelation process, the separation of o-GQDs’ photoexcited electron hole pairs leads to their rapid electron transfer to Al³⁺, in turn leading to the occurrence of a fluorescence-quenching phenomenon. In addition, there was a good linear relationship between the concentration of the Al³⁺ ions and the fluorescence intensity, and the correlation coefficient of the linear regression equation was 0.9937. This illustrates the potential for the wide application of GQDs in sensing systems, while also demonstrating that Al³⁺ sensors can be used to detect Al³⁺ ions.

Due to the rapid development of industrialization, various environmental problems such as water resource pollution are gradually emerging, among which heavy metal pollution is harmful to both human beings and the environment. As a result, there are many metal ion detection methods, among which fluorescence detection stands out because of its rapid, sensitive, low cost and non-toxic characteristics. In recent years, graphene quantum dots have been widely used and studied due to their excellent properties such as high stability, low toxicity and water solubility, and have a broad prospect in the field of metal ion detection. A novel high fluorescence Cu²⁺, Co²⁺ sensing probe produced by graphene quantum hydrothermal treatment is reported. After heat treatment with hydrazine hydrate, the small-molecule precursor nitronaphthalene synthesized by self-nitrification was transformed from blue fluorescent GQDs to green fluorescent amino-functionalized N–GQDs. Compared with other metal ions, N–GQDs are more sensitive to Cu²⁺ and Co²⁺ on the surface, and N–GQDs have much higher selectivity to Cu²⁺ and Co²⁺ than GQDs. The strategy proposed here is simple and economical in design.

Thermal damage to diamonds is a major limitation in laser powder bed fusion (LPBF) processing of metal matrix diamond composites. In this paper, a numerical simulation model was established to describe the thermal effect of the Diamond-CuSn10 composite on the LPBF process. The simulation results show that the temperature of the diamond presents a double-peak structure, and the double-peak temperature curve shape can be modulated by modifying the laser scanning offset and the size of the diamond powder. And it suggests that the heat of the diamond mainly comes from the transfer of the molten pool. Then, combined with the experimental phenomenon, the mechanism of diamond graphitization in the LPBF process is analyzed. It indicates that since the surface defects of the diamond inhibit the heat conduction of the diamond, the temperature accumulates on the surface, leading to the graphitization of the diamond. Finally, based on this model, the potential of Ti-coated diamonds to prevent and reduce thermal damage in the LPBF process has been extensively studied. It is found that a Ti coating with low thermal conductivity can effectively reduce diamond temperature and improve diamond graphitization resistance. This study can provide a good method and basis for the preliminary selection of LPBF process parameters and the understanding of the graphitization mechanism of diamond tools.

High-efficiency and high-quality removal of sulfurized silicone rubber from insulator surfaces is paramount for high-voltage power systems. To address this issue, and aiming to achieve precise and nondestructive cleaning of room temperature vulcanized (RTV) coatings, we selected millisecond laser cleaning technology in this study. Successful and efficient cleaning of the RTV coating was performed by adjusting laser parameters. Characterization techniques, including scanning electron microscopy, energy-dispersive x-ray spectroscopy, and confocal microscopy, were employed to comprehensively assess the cleaning effects and ensure the integrity of the substrate surface. The results indicate that by adjusting the scanning power combination of the high power of the millisecond pulse laser to 200 W and the low power of 150 W, the glass substrate surface maintains excellent roughness and micro-morphological features after laser cleaning, providing optimal conditions for subsequent processing and utilization. This research contributes an efficient and cost-effective solution to the insulation treatment process in high-voltage power systems.

The properties of flux-cored Zn-Al filler metals are prone to deteriorating due to corrosion, making filler metals unusable. In this study, flux-cored Zn-2Al-xGe (x = 0, 0.3, 0.5, and 0.8 wt.%) filler metals are prepared to explore the effect of minor Ge on the corrosion resistance of Zn-2Al filler metals. The salt spray test is carried out on filler metals. A scanning transmission electron microscope is used to identify the phases in filler metals. The electrochemical performance of filler metals was tested by a workstation. The findings indicate that the microstructure of the Zn-2Al filler metal is composed of α-Al and η-Zn. Diamond-Ge forms in the microstructure of the Zn-2Al filler metal due to the introduction of Ge. Zn-2Al-xGe filler metals exhibit pitting corrosion characterized by intergranular corrosion (IGC) in the salt spray environment. Ge improves the IGC resistance of filler metals by changing the distribution of α-Al in the filler metal. The Zn-2Al-0.3Ge filler metal demonstrates the most excellent corrosion resistance. It has 16% elongation after 15 d of corrosion, which is higher than that of Zn-2Al by 13.6%.