Metainterfaces with mechanical, thermal, and active programming properties based on programmable orientation-distributed biometric architectonics.

Interfaces between different materials crucially determine the performance of multi-material systems, impacting a wide range of industries. Currently, precisely programming interfaces with distinct properties at different localized interface positions remains a challenge, leading to limited interface adaptability and unpredictable interface failures, thus hindering the development of next-generation materials and engineering systems with highly customizable multiphysical interface performances. Our research introduces programmable "metainterfaces" for the first time, featuring engineerable biometric architectonics that allows for mechanically, thermally, and actively programmed distribution of interfacial effects by its orientation, driven by artificial intelligence. Enabled by metainterfaces, we showcased improved mechanical properties of future composite metamaterials by programming interface resistance customized to the decoupling modes of distinct lattice topologies. Additionally, we demonstrate enhanced and programmable impact mechanics in fish scale assemblies equipped with pre-programmed metainterface sheets. The proposed metainterface also allows for coolant flow programming in thermal management systems, opening new avenues for development of highly customizable thermos-mechanical systems. Additionally, we introduce digitally controlled "metadisks" enabled by metainterfaces as novel solutions for actively programmable interface systems in robotics, offering real-time adaptive and intelligent interfacial mechanics. This research sets the foundation for next-generation multi-material systems with precisely programmed interfacial effects, offering broad applicability in areas such as smart materials, advanced thermal management, and intelligent robotics.

Progress in in situ x-ray imaging of welding process.

Welding has been widely used in industry for hundreds of years, and pursuing higher weld quality requires a better understanding of the welding process. The x-ray imaging technique is a powerful tool to in situ observe the inner characteristics of the melt pool in the welding process. Here, current progress in in situ x-ray imaging of the welding process is concluded, including the experiments based on the laboratory-based single x-ray imaging system, the laboratory-based double x-ray imaging system, and the synchrotron radiation tomography system. The corresponding experimental results with the in situ x-ray imaging technique about the formation and evolution of the keyhole, melt pool, pore, solidification crack, etc., have been introduced. A new understanding of welding based on the current progress in in situ x-ray imaging of additive manufacturing is concluded. In addition, the future development trend of applying x-ray imaging technology in the field of monitoring the welding process is proposed.