Gutmann Florian, Stilz Maximilian, Patil Sankalp, Fischer Frank, Hoschke Klaus, Ganzenmüller Georg, Hiermaier Stefan
Department of Sustainable Systems Engineering-INATECH, Albert-Ludwigs-University Freiburg, Emmy-Noether-Straße 2, 79110 Freiburg, Germany.
Fraunhofer Institute for High-Speed Dynamics (EMI), Ernst-Zermelo-Str. 4, 79104 Freiburg, Germany.
Materials (Basel). 2023 Feb 22;16(5):1797. doi: 10.3390/ma16051797.
This work introduced additively manufactured non-assembly, miniaturized pin-joints for pantographic metamaterials as perfect pivots. The titanium alloy Ti6Al4V was utilized with laser powder bed fusion technology. The pin-joints were produced using optimized process parameters required for manufacturing miniaturized joints, and they were printed at a particular angle to the build platform. Additionally, this process optimization will eliminate the requirement to geometrically compensate the computer-aided design model, allowing for even further miniaturization. In this work, pin-joint lattice structures known as pantographic metamaterials were taken into consideration. The mechanical behavior of the metamaterial was characterized by bias extension tests and cyclic fatigue experiments, showing superior levels of performance (no sign of fatigue for 100 cycles of an elongation of approximately 20%) in comparison to classic pantographic metamaterials made with rigid pivots. The individual pin-joints, with a pin diameter of 350 to 670 µm, were analyzed using computed tomography scans, indicating that the mechanism of the rotational joint functions well even though the clearance of 115 to 132 µm between the moving parts is comparable to the nominal spatial resolution of the printing process. Our findings emphasize new possibilities to develop novel mechanical metamaterials with actual moving joints on a small scale. The results will also support stiffness-optimized metamaterials with variable-resistance torque for non-assembly pin-joints in the future.
这项工作介绍了用于缩放形超材料的增材制造非组装小型销关节，作为理想的枢轴。采用激光粉末床熔融技术使用钛合金Ti6Al4V。销关节是使用制造小型关节所需的优化工艺参数生产的，并以特定角度打印到构建平台上。此外，这种工艺优化将消除对计算机辅助设计模型进行几何补偿的需求，从而实现进一步的小型化。在这项工作中，考虑了被称为缩放形超材料的销关节晶格结构。通过偏置拉伸试验和循环疲劳实验对超材料的力学行为进行了表征，与采用刚性枢轴制成的经典缩放形超材料相比，其表现出卓越的性能水平（在伸长约20%的情况下进行100次循环无疲劳迹象）。使用计算机断层扫描对直径为350至670 µm的单个销关节进行了分析，结果表明，尽管运动部件之间115至132 µm的间隙与打印过程的标称空间分辨率相当，但旋转关节的机制运行良好。我们的研究结果强调了开发具有实际小型活动关节的新型机械超材料的新可能性。这些结果也将为未来用于非组装销关节的具有可变阻力扭矩的刚度优化超材料提供支持。
