MXenes， with the general formula M{}_{n+\mathrm{1}}^{}X_nT_x， are a novel class 2D nanomaterials composed of transition metallic compounds with nitrogen or carbon. Due to the rich functional groups on its surface， MXenes have been widely used in biosensing， tumor therapy， tracer imaging， and other biological fields. MXenes exhibit strong antibacterial activity and certain active oxygen-scavenging ability， and these biological characteristics closely align with the required properties of wound dressings， making MXenes a popular material for wound dressing modification in recent years. In this review， the structure， properties， and preparation methods of MXenes are introduced in detail， and the latest research progress of MXenes and their composites in the field of wound repair， bone defect repair， and muscle repair are reviewed.

MXene is a graphene-like two-dimensional transition-metal carbide，nitride，or carbonitride nanomaterial，typically exhibiting quasi-metallic or narrow-bandgap semiconductor characteristics. Recently，MXene has garnered significant interest in the photothermal conversion field owing to its remarkable attributes，including outstanding broad-spectrum light absorption performance，ultrahigh specific surface area，varied and adjustable surface functional groups，versatile imaging modes， biocompatibility，low toxicity，and more. This review offers a comprehensive look at the preparation techniques，underlying principles， and surface functional group attributes of MXene， focusing on the latest advancements of MXene，especially the MXene-based composite materials， in the fields of photothermal water evaporation， catalysis， sterilization， and therapy. Besides，leveraging the full-spectrum and near-infrared absorption properties of MXene，this review also delves into the design principles of MXene-based photothermal materials. It explores the synergistic effects of their photothermal effects in the photocatalysis and enzyme catalysis applications. Finally，the challenges and prospects of MXene used in the photothermal field are summarized briefly.

As electronic components become increasingly intelligent， lightweight， and integrated， the power density of electronic equipment increases dramatically. The development of high-performance thermally conductive composites has thus become critically important. One-dimensional polymer nanofibers are conducive to the effective connection of thermally conductive fillers in the axial direction and promote the formation of effective thermal conductivity paths between adjacent thermally conductive fillers. Consequently， when the same content of fillers is added in polymer matrix， these kind of anisotropic composites usually exhibit superior thermal conductivity， which has attracted widespread attention from researchers. This paper systematically summarizes the research progress of polymer nanofiber-based anisotropic thermally conductive composites including cellulose nanofibers， aramid nanofibers， poly-paraphenylene benzobisoxazole nanofibers， and electrospun nanofibers， and discusses the regulation effect of low-dimensional thermally conductive fillers on the properties of polymer nanofiber-based composites. Finally， the challenges and future development directions of nanofiber-based thermally conductive composites are prospected.

CrCoNi-based medium-entropy alloys have garnered substantial research attention as high-performance metallic materials， owing to their exceptional synergy between strength and toughness. This review provides a systematic overview of the core strengthening-toughening mechanisms and pivotal performance-regulation strategies. At the atomic scale， chemical short-range order （CSRO） promotes the formation of locally ordered clusters， which impede dislocation motion. Moreover， the dynamic evolution of CSRO interacts with stacking fault energy， facilitating the generation of stacking faults and deformation twins. On the nanoscale， a three-dimensional twin network not only restricts dislocation glide but also provides channels for slip. Additionally， the introduction of nanoscale precipitates modifies the dominant deformation mechanism， enabling the simultaneous enhancement of strength and ductility. Further research reveals that precise control over heat treatment， additive manufacturing， and plastic deformation processes can effectively tailor strengthening phases and gradient structures， thereby improving mechanical properties. The alloy demonstrates a distinct advantage at cryogenic temperatures， where multiple deformation mechanisms are activated， resulting in the concurrent enhancement of strength and toughness. Future research endeavors should concentrate on elucidating the dominant mechanisms at room temperature and enhancing environmental adaptability to facilitate engineering applications.

Aluminum bronze alloys are widely used in marine industrial fields such as ship propellers， high-pressure pump bodies， and valves due to their excellent mechanical properties， cavitation resistance， and corrosion resistance. However， traditional casting processes have drawbacks in the preparation of aluminum bronze alloys， including long production cycles， high costs， and low part precision， and the as-cast alloys are prone to internal porosity， shrinkage cavities， and surface slag inclusions. As a novel advanced manufacturing technology， laser additive manufacturing enables rapid forming of metal components， and its rapid cooling process facilitates the formation of fine grains， thereby improving alloy performance， demonstrating great potential and broad prospects in the preparation of aluminum bronze alloys. This paper focuses on two processes， selective laser melting and laser melting deposition， introduces the laser additive manufacturing processes for aluminum bronze alloys and the associated challenges， reviews recent research achievements both domestically and internationally on process characteristics， microstructure， and properties， analyzes the main existing problems and research gaps， and finally points out that expanding the variety of aluminum bronze alloy materials for laser additive manufacturing， optimizing laser process parameters， and controlling defects during the forming process are key directions for future research.

The application of laser powder bed fusion （LPBF） on TC4 titanium alloy is an important way to achieve lightweight and integration in aviation， aerospace， medical， electronics，and other fields at present. In this paper， the effects of laser powder bed fusion on microstructure and defects of TC4 titanium alloy and its mechanism are systematically summarized. The research status of the influence of LPBF parameters and heat treatment methods on the tensile properties of TC4 alloy formed by LPBF is reviewed in detail as well. On this basis， in view of the bottleneck on application of LPBF TC4 titanium alloy at the present stage， the research status of fatigue properties and fracture toughness of TC4 alloy formed by LPBF is systematically summarized， and the effective post processing methods to improve the fatigue property and fracture toughness of TC4 titanium alloy fabricated by additive manufacturing are pointed out， and the development trends are also discussed.

Arc heat sources are extensively employed in welding and additive manufacturing， emerging as an indispensable core energy medium for the joining and forming of metal components. Nevertheless， traditional arc heat sources are plagued by inherent flaws， such as the highly-coupled heat and mass transfer behaviors that are difficult to control independently. This results in a profound coupling between the heat input to the workpiece and the wire deposition rate， posing a significant challenge in simultaneously satisfying the dual demands of high-efficiency deposition and high-quality forming. Consequently， it severely restricts the high-performance manufacturing process of large and complex structural components. Therefore， conducting research on the decoupling of heat and mass transfer in arc heat sources is of immense theoretical value and urgent engineering significance for transcending traditional arc manufacturing technology. This paper presents a systematic review of the research progress in the decoupling technology of heat and mass transfer in arc heat sources， with a particular focus on the state-of-the-art cross-arc configuration. From a physical perspective， this technology achieves orthogonal decoupling of heat input and mass transport through the coordinated arrangement of independent heat sources and independent mass sources. The article offers an in-depth examination of key aspects， including the stability control， droplet transfer behavior， and development challenges of cross-arc heat sources. Its objective is to provide a robust theoretical foundation and feasible technical route support for constructing a new generation of intelligent arc manufacturing systems with independent and controllable heat and mass.

In the field of electronic packaging， Au-Sn eutectic alloy （AuSn20） serves as key solder materials， and its preparation process directly affects the packaging performance and reliability. However， due to the brittleness of AuSn20， there is currently no efficient method for the preparation of AuSn20 solder balls. This study uses pulsated orifice ejection method to achieve the high precision and consistency of the on-demand preparation of AuSn20 solder balls. The results show that various specifications of AuSn20 solder balls are prepared under optimal process conditions， with the smallest specification being 50 μm， and the maximum standard deviation of the target particle size being 1.58 μm， significantly improving the preparation accuracy. Microstructural analysis reveals that the solder balls are mainly composed of δ-AuSn and ζ'-Au₅Sn eutectic phases， with no abnormal new phases observed. After reflow treatment， the composition distribution inside the solder ball tends to be uniform.Interface reaction studies show that due to the synergistic diffusion of Ni atoms in the diffusion barrier layer， a complex intermetallic compounds （Au，Ni）Sn and （Au，Ni）₃Sn₂ are formed at the interface joint. The AuSn20 solder balls prepared in this study not only achieve precise control of particle size and consistent thermal history， but also show excellent interface stability and structural integrity under simulated service conditions， opening up new application avenues for Au-Sn alloy brazing materials in advanced electronic packaging.

To solve the problem that the brazing temperature of existing filler metals for joining the superalloy GH4169 exceeds its δ phase solid solution temperature， which leads to the dissolution of the δ phase during brazing and consequently degrades the high-temperature performance of the alloy， this work conducts a study on a novel low-temperature Ni-based brazing filler for GH4169 and optimizes the brazing process. The brazing temperature is set at 980 ℃， which is comparable to the solid solution temperature of the alloy， in order to achieve a good match between brazing and heat treatment temperatures. Based on the binary phase diagrams， with Pd as the primary melting point depressant and B and Si as the secondary melting point depressants， a novel Ni-based brazing filler of 36Pd-10Cr-3B-1Si-Ni is configured and smelted. The melting point， wettability， and weldability of the novel filler on GH4169-GH536 butt joints are investigated. The results show that the solidus and liquidus temperatures of the novel filler are in the range of 828.82-961.43 ℃， and the wetting angle is 7.8°at 980 ℃ for 15 min， demonstrating excellent wettability， thereby optimizing the brazing process parameters. Under the process conditions of 980 ℃ for 60 min and a joint clearance-free assembly， the maximum room-temperature tensile strength of the brazed joint reaches 586 MPa， which exceeds that of the conventional BNi-2 brazing filler； the high-temperature creep rupture performance at high temperature exceeds 10 h， and the joint is free of obvious defects. Therefore， the novel low-melting Ni-based brazing filler of 36Pd-10Cr-3B-1Si-Ni can be used to achieve effective brazing of GH4169 while preserving its original microstructure and properties.

Traditional cemented carbides typically use Co as the binder. In recent years， novel cemented carbides employing high-entropy alloys as substitutes for Co have demonstrated significant advantages in improving hardness， fracture toughness， high-temperature oxidation resistance， and corrosion resistance. In cemented carbides with Cr- and Mo-containing high-entropy alloy binders， the strong carbide-forming elements Cr and Mo influence the carbon content in the binder phase and the existing form of carbon in the alloy， thereby affecting the mechanical properties. This work aims to investigate the influence mechanism of carbon addition on the microstructure and grain growth of WC-CoNiFeCrMo cemented carbides， and to explore the variation patterns of their mechanical properties. The results show that with increasing carbon addition， the WC grain size in the WC-CoNiFeCrMo alloy changes slightly， the coercive force gradually decreases， and the hardness decreases slightly. The fracture toughness and transverse rupture strength of the alloy first increase and then decrease， reaching peak values when the total carbon content of the alloy increases to 5.73%（mass fraction）， with a fracture toughness of 18.52 MPa·m^1/2 and a transverse rupture strength of 2991 MPa. With further increase in carbon addition， carburized phases appear in the alloy， and the fracture toughness and transverse rupture strength decrease significantly.