New Rosette Tools for Developing Rotational Vibration-assisted Incremental Sheet Forming
New Rosette Tools for Developing Rotational Vibration-assisted Incremental Sheet Forming
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DOI：
10.1016/j.jmatprotec.2024.118311
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发表时间：
2024-01
影响因子：
6.3
通讯作者：
H. Long;W.X. Peng;Z.D. Chang;H. Zhu;Y.J. Jiang;Z.H. Li
中科院分区：
文献类型：
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作者：
H. Long;W.X. Peng;Z.D. Chang;H. Zhu;Y.J. Jiang;Z.H. Li
板料渐进成形（ISF）的一个主要限制是难以制造难成形材料。现有的ISF工艺变体需要额外的系统或设备，这损害了工艺灵活性和简单性，这是ISF的独特优势。在这项研究中，提出了一种新型的玫瑰花形工具，用于开发一种新的ISF工艺，以提高材料的成形性，命名为旋转振动辅助ISF（RV-ISF）。在RV-ISF实验中，通过在250-450 °C范围内的局部成形区产生低频和低振幅振动以及升高温度，成功地成形了一种难以成形的材料，即镁合金AZ 31 B。通过开发新的RV-ISF，它已经实现了60%的断裂深度增加比搅拌摩擦ISF和超过46%的成形力比传统的ISF降低。实验评估和分析预测的温度升高，成形力和流动应力降低的结论是，热效应和振动软化的组合是导致显着的成形性提高的关键机制。结果表明，玫瑰花刀具的设计和刀具转速是决定热产生和传递以及振动频率和振幅的关键因素。对显微组织演变的研究表明，玫瑰花刀具产生的低频低幅振动激活了位错和动态再结晶，细化了晶粒，提高了显微硬度。新开发的RV-ISF具有制造其他难以成形的材料和复杂几何形状的板材产品的潜力，克服了当前ISF技术的成形性限制。
A major limitation of the incremental sheet forming (ISF) is its difficulties to manufacture hard-to-form materials. The existing ISF process variants require additional systems or devices, which compromises the process flexibility and simplicity, the unique advantages of the ISF. In this study, a novel type of rosette tools is proposed for developing a new ISF process to improve material formability, named as Rotational Vibration-assisted ISF (RV-ISF). A hard-to-form material, magnesium alloy AZ31B, has been successfully formed in the RV-ISF experiment by creating low-frequency and low-amplitude vibrations, and elevated temperatures at the local forming zone in the range of 250–450 °C. By developing the new RV-ISF, it has achieved a 60% increase in fracture depth than that by friction-stir ISF and more than 46% reduction in forming force than that by the conventional ISF. Experimental evaluation and analytical prediction of temperature increase, forming force and flow-stress reduction have concluded that the combined thermal effect and vibration softening is the key mechanism leading to the significant formability enhancement. The results show that both the rosette tool design and tool rotational speed are critical factors determining heat generation and transfer as well as vibration frequency and amplitude. Investigation on microstructural evolution has revealed that the low-frequency and low-amplitude vibrations created by the rosette tool have activated dislocations and dynamic recrystallization, and produced refined grains and increased micro hardness. The new RV-ISF developed has potentials to manufacture other hard-to-form materials and complex geometries of sheet products, overcoming the formability limitation of the current ISF technology.