Zhao Yuzhu, Zhang Shijing, Li Jing, Deng Jie, Liu Yingxiang
State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001, China.
Adv Sci (Weinh). 2025 Mar;12(11):e2415138. doi: 10.1002/advs.202415138. Epub 2025 Jan 30.
The wetting and spreading behaviors of metal droplets on solid substrates are critical aspects of additive manufacturing. However, the inherent characteristics of metal droplets, including high surface tension, elevated viscosity, and extreme temperatures, pose significant challenges for wetting and spreading on nonwetting substrates. Herein, this work proposes a strategy that employs a two-dimensional (2D) orthogonal ultrasonic field to construct a vibration deposition substrate with radial vibration amplitude gradient, thereby enhancing the wettability and adhesive strength of impacting metal droplets ejected by a piezoelectric micro-jet device. First, a 2D ultrasonic vibration device is designed based on the combination of longitudinal vibration modes. Additionally, oblique and circular vibration trajectories are synthesized. The vibration amplitude distributions and trajectories of the deposition substrate are verified utilizing the finite element method. Subsequently, the experimental results demonstrate that the contact angle is decreased by 24.7%, the spreading diameter is increased by 10.3%, and the adhesive strength is enhanced by 5.4 times compared to deposition on a static substrate. The 2D ultrasonic field facilitates the transition of metal droplets from a non-wetting state to a wetting state on the nonwetting substrate, which highlights the versatility and adaptability of ultrasonic strategy for expanding the applications of metal droplets.
金属液滴在固体基板上的润湿和铺展行为是增材制造的关键方面。然而，金属液滴的固有特性，包括高表面张力、高粘度和极端温度，对在非润湿基板上的润湿和铺展构成了重大挑战。在此，本工作提出了一种策略，即采用二维（2D）正交超声场来构建具有径向振动幅度梯度的振动沉积基板，从而提高由压电微喷射装置喷射出的冲击金属液滴的润湿性和粘附强度。首先，基于纵向振动模式的组合设计了一种二维超声振动装置。此外，合成了倾斜和圆形振动轨迹。利用有限元方法验证了沉积基板的振动幅度分布和轨迹。随后，实验结果表明，与在静态基板上沉积相比，接触角降低了24.7%，铺展直径增加了10.3%，粘附强度提高了5.4倍。二维超声场促进了金属液滴在非润湿基板上从非润湿状态转变为润湿状态，这突出了超声策略在扩展金属液滴应用方面的通用性和适应性。
