Hui Huang

Biomachining (BM) is an emerging bio-assisted manufacturing approach that uses microbial metabolism and bioelectrochemical reactions to remove material und

Biomachining, an environmentally friendly technique that utilizes microbial metabolism for material removal, enables surface texturing free from thermal-induced damage. This work presents the fabrication of superhydrophobic nanostructured surfaces on H62 brass through a mask-assisted jet biomachining approach, followed by low-surface-energy modification. The as-prepared surfaces exhibit a water contact angle of ~154° and sustain long-term hydrophobic stability for over 50 days. Key process parameters (machining time, nozzle diameter, jet velocity) were optimized via Response Surface Methodology, establishing highly accurate predictive models for material removal rate, contact angle, and removal depth, with prediction errors controlled within ≤7.8%. Electrochemical measurements in a 3.5 wt.% NaCl solution demonstrate that the superhydrophobic interface significantly enhances corrosion resistance: compared to the untextured brass, the corrosion current density decreases by approximately one order of magnitude, achieving an inhibition efficiency of 89.67%. This improvement is ascribed to the air cushions trapped within the micro/nano-textured interface, which minimize solid-liquid contact and act as a physical barrier against corrosive species. Furthermore, the surface displays excellent anti-adhesion properties. This study provides a sustainable and efficient strategy for the surface modification and interface engineering of metallic components, offering promising prospects for corrosion protection in marine environments.

Multi-robot systems, owing to their parallel operation and cooperative capabilities, have become an important means of improving the efficiency of complex workpiece machining. However, task allocation methods directly determine the overall system performance, which is particularly critical in scenarios with high curvature and stringent stiffness requirements. This study focuses on a Dual-Robot Carving System (DRCS) and proposes a task allocation method that incorporates stiffness performance constraints, using stereoscopic stone carving as a representative application. First, a workstation optimization model is developed based on the average normal stiffness as the evaluation metric, enabling the selection and allocation of high-complexity tasks. This approach not only ensures machining stiffness but also effectively decouples the task allocation problem. Subsequently, two allocation strategies are designed for low-complexity tasks: one based on machinability and the other on machining time balancing. Comparative simulations and physical experiments are conducted to evaluate the efficiency differences between the proposed methods and the single-robot machining mode. The results show that the machining time balancing strategy improves efficiency by 14.33% compared with the machinability-based strategy, and by 84.78% compared with the single-robot mode. These findings demonstrate the effectiveness of the proposed method in enhancing dual-robot collaborative efficiency and provide a novel modeling perspective and technical support for multi-robot task allocation under stiffness constraints in complex workpiece machining.

Electrochemical mechanical polishing is a critical technology for improving the surface quality of silicon carbide (SiC) substrates. However, the fundamental electrochemical corrosion mechanism of the SiC substrate remains incompletely understood. In this study, the electrochemical corrosion behavior of the SiC substrate is explored through comprehensive experiments and molecular dynamics simulations. Key findings demonstrated that the 4H-0° SiC exhibited the highest corrosion rate in a 0.6 mol/L NaCl electrolyte. The corrosion rate increased as the voltage rose within the range of 2 to 20 V. When the voltage was between 20 and 25 V, the system entered the stable passivation region, while when the voltage was 25 to 30 V, partial dissolution of the surface oxide layer occurred. Molecular dynamics simulations further revealed that both amorphization degree and reaction depth on the SiC surface showed a decreasing trend at elevated voltages, suggesting a corresponding reduction in the corrosion rate when the voltage exceeded the optimal range. OH⁻, O²⁻, and •OH generated by the electrolysis of water during electrochemical corrosion would rapidly react with the surface of the SiC anode, and subsequently form a SiO₂ modified layer. Moreover, these atomistic insights establish a scientific foundation for achieving superior surface integrity in large-diameter SiC substrates through optimized electrochemical mechanical polishing processes.