Electrochemical testing techniques，featuring high sensitivity，in-situ real-time monitoring，and multi-scale analysis，have become a core tool for studying corrosion mechanisms and evaluating protective performance of materials. This paper reviews the classification and recent advances of electrochemical testing methods. The characteristics and applicable conditions of traditional and localized electrochemical techniques are analyzed and compared. The role of multi-technique coupling and artificial intelligence data analysis in testing complex corrosion systems and elucidating mechanisms are discussed. The application of electrochemical techniques from the perspectives of corrosion behavior and mechanism research， protective performance evaluation， and online corrosion monitoring are systematically summarized. Finally， it points out that the development of electrochemical testing techniques lies not only in the popularization of single techniques but also in prioritizing the advancement of multi-technique coupling and high-spatiotemporal-resolution in-situ electrochemical characterization， enabling in-depth analysis from the extraction of intrinsic interfacial reaction parameters to the comprehensive understanding of corrosion mechanisms. On this basis，data-driven approaches and intelligent algorithms are integrated to establish quantitative correlations between electrochemical responses and the service life of materials. Furthermore，integrated and lightweight intelligent monitoring systems enable real-time assessment and lifetime prediction under complex engineering conditions，thereby promoting the transition of corrosion electrochemical testing from laboratory-based mechanistic studies to full-life-cycle safety management of engineering materials.
Friction stir welding and its derived solid-state additive manufacturing technologies stand as one of the effective approaches to avoid melting defects and achieve the fabrication of high-performance lightweight alloy components. However，the friction stir welding and solid-state additive manufacturing processes involve complex thermo-mechanical-fluid-microstructure couplings，posing significant challenges to traditional trial-and-error methods for process optimization. The emergence of machine learning provides a transformative solution for process understanding and intelligent control in this field. This paper presents a systematic review of machine learning applications in friction stir welding and additive friction stir deposition. It categorizes and elaborates on the current research status and data processing strategies in aspects such as performance prediction，defect detection，and in-situ control. Addressing the limitations of purely data-driven models，it focuses on investigating different fusion paradigms of physics-informed machine learning and their cutting-edge applications. Finally， it points out that future research should concentrate on further developing generalizable prediction models，achieving real-time closed-loop intelligent control，and integrating active learning for autonomous process exploration，aiming to provide references for advancing these technologies toward intelligent and high-performance development.
China’s medium- and long-term space science development program clearly puts forward the major tasks of rapidly promoting deep space exploration and accelerating the construction of a space power. The increasingly complex and extreme thermal environment in space imposes more stringent requirements on spacecraft thermal control systems. Conventional thermal control materials exhibit limited and static thermoregulatory properties， failing to meet evolving performance demands. In contrast， smart thermal control materials can dynamically modulate their physical characteristics in response to external stimuli， thereby enabling smart regulation of spacecraft heat dissipation and insulation capabilities， and significantly improving the precision and energy efficiency of thermal management systems. As a result， smart thermal control technology has emerged as a critical development direction for next-generation spacecraft thermal control systems. This review systematically outlines the research progress of typical smart thermal control materials， including thermochromic and electrochromic materials， their applications in space missions and the key challenges in this field. To enable the widespread application of smart thermal control coatings， future research work should be carried out in the AI-assisted material design， low-cost fabrication， failure analysis and life prediction under space environments， and system integration. These endeavors are of great significance for driving innovation in aerospace thermal control technology， accelerating the iterative upgrading of thermal management systems， and supporting the steady progression of national space strategy.
Laser cladding uses a high-energy laser to rapidly melt cladding materials with the substrate surface， forming a metallurgically bonded coating upon solidification. It is a key technology for producing high-performance surface coatings and remanufacturing metallic components. Recently， laser cladding has evolved from a surface coating technique into a comprehensive process integrating coating fabrication， repair of damaged parts， and additive manufacturing， showing great potential in new material development. This review first elaborates the metallurgical characteristics of laser cladding metals， then highlights process innovations in four directions： high efficiency， hybridization， specialization， and intellectualization. It further addresses the role of laser cladding in material development and fabrication， systematically reviewing research progress on conventional alloys， high-entropy alloys， amorphous alloys， metal matrix composites， and functionally graded materials， and summarizing their strengthening mechanisms and typical applications. However， challenges remain for laser cladding fabricating materials， including incomplete non-equilibrium solidification theories， lack of quantitative process-microstructure-property models， and inadequate monitoring and evaluation techniques. Future efforts should prioritize data-driven intelligent optimization， novel material system design， extreme-environment adaptability， and integration of multi-energy-field hybrid processes and combined process chains.
As modern high-end manufacturing increasingly trends towards miniaturization and multifunctionality， achieving high-quality joining of dissimilar materials has encountered severe technical bottlenecks. Addressing this challenge， nano-multilayer films have emerged as a highly promising technological pathway for realizing low-temperature， highly reliable bonding， owing to their pronounced size effects and high-density interfacial structures. This review focuses on immiscible nano-multilayer films of the Cu/X （X=W， V， Mo， Ta， Nb） refractory metal systems， systematically elucidating the thermal stability evolution mechanisms governed by interfacial microstructures， as well as the intrinsic mechanisms that modulate mechanical properties and irradiation responses. Furthermore， it summarizes the recent research progress on their applications as high-performance brazing fillers or interlayers in brazing and diffusion bonding， highlighting their critical roles in mitigating residual stress in joints and suppressing the formation of brittle intermetallic compounds. Finally， it points out that future research should focus on the multi-scale computational modeling of spatial interfacial transport mechanisms and interfacial evolution mechanisms under multi-field coupling. Overcoming the high-temperature thermal stability bottleneck of this system is also identified as a key direction to advance its engineering applications.
