In order to meet the growing design demands for shape and structure of magnetic functional materials, particularly Magnetorheological Elastomers (MREs), additive manufacturing technology has been introduced into MRE production. Reported works of printable MRE (-MRE) have successfully obtained high relative magnetorheological (MR) performance comparable to traditional MRE. However, there are still few studies on -MRE with both high relative and absolute MR effects that is required for some applications such as intelligent dampers in automotive industry. In this study, polyurethane (TPU) and carbonyl iron powder (CIP) were utilized as raw materials to formulate -MRE with high printability and high comprehensive MR performance. Based on the fused deposition modeling (FDM) process, a printing strategy suitable for this -MRE material was determined through experimental design (DOE). The test result showed that the comprehensive MR performance of the -MRE sheet samples obtained through linear printing path exceeded the majority of previously reported -MRE materials. In addition, based on the analysis of the correlation between magnetic hysteresis like effect and MR effects, a circular printing path that may be beneficial for improving MR performance was proposed and corresponding -MRE sheet sample was printed. The test results showed that compared with the linear printing path, the circular printing path further increases the comprehensive MR effect of the sheet sample to a maximum absolute MR effect of 4.2 MPa and a maximum relative MR effect of 620 %, which is comparable to most conventional MRE materials. Additionally, a theoretical framework associating magnetic field strength and filling density was proposed to explain peculiar phenomena observed in the experiments. On the basis of previous research on MREs and filler modified elastomers, a hypothesis was proposed to link magnetic field intensity with filler density, allowing the existing theory of filler modified elastomers to be used to explain the special phenomena observed in our experiments.

中文翻译：

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新型3D打印磁流变弹性体（MRE）的制造和性能研究


为了满足磁性功能材料，特别是磁流变弹性体（MRE）形状和结构日益增长的设计需求，增材制造技术已被引入MRE生产中。可打印磁流变（-MRE）的报道工作已成功获得与传统磁流变（MRE）相当的高相对磁流变（MR）性能。然而，对于汽车工业中的智能阻尼器等某些应用所需的具有高相对和绝对磁流变效应的-MRE的研究仍然很少。本研究以聚氨酯（TPU）和羰基铁粉（CIP）为原料，配制出具有高印刷适性和高综合MR性能的-MRE。基于熔融沉积成型（FDM）工艺，通过实验设计（DOE）确定了适合这种-MRE材料的打印策略。测试结果表明，通过线性打印路径获得的-MRE片材样品的综合MR性能超过了之前报道的大多数-MRE材料。此外，基于类磁滞效应与MR效应之间相关性的分析，提出了可能有利于提高MR性能的圆形打印路径，并打印了相应的-MRE片材样本。测试结果表明，与直线打印路径相比，圆形打印路径进一步提高了片材样品的综合MR效果，最大绝对MR效果为4.2MPa，最大相对MR效果为620%，与大多数纸张样品的MR效果相当。传统的 MRE 材料。此外，提出了一个将磁场强度和填充密度相关联的理论框架来解释实验中观察到的特殊现象。 在之前对MRE和填料改性弹性体研究的基础上，提出了将磁场强度与填料密度联系起来的假设，使得现有的填料改性弹性体理论可以用来解释我们实验中观察到的特殊现象。