Predictive Thermal Modeling and Characterization of Ultrasonic Consolidation Process for Thermoplastic Composites
Predictive Thermal Modeling and Characterization of Ultrasonic Consolidation Process for Thermoplastic Composites
复制标题
热塑性复合材料超声波固结过程的预测热建模和表征
DOI：
10.1115/1.4056147
复制
发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Palardy, Genevieve
中科院分区：
文献类型：
--
作者：
Kirby, Madeline;Naderi, Armaghan;Palardy, Genevieve
热塑性复合材料的超声固化是一种极具吸引力和发展前景的高性能复合材料制备方法。本工作的重点是干碳纤维（CF）织物与高温聚苯硫醚（PPS）薄膜的超临界。评估该过程可行性的实验性试验是耗时的。因此，预测热模型将有助于工艺参数选择，以减少昂贵的试错方法。本文提出了一个二维有限元模型的样品固结，纳入方程的粘弹性加热，基质相变，和材料性能。将感兴趣的节点的理论温度曲线与各种控制参数（即，焊接时间和超声焊极的垂直位移），并且在加热阶段显示出良好的一致性。发现低于1750 ms的焊接时间值不足以达到熔化温度，而高于3000 ms的焊接时间导致最低的平均空隙含量（2.43 ± 0.81%）。更具体地，材料在熔融温度以上所花费的时间，即，停留时间被确定为可以估计导致更好的固结和更低的空隙含量（空隙含量低于2.5%的时间高于2600 ms）的情况的参数。X射线衍射（XRD）表征显示，由于高冷却速率（70 °C/s至108 °C/s），USC工艺导致大部分无定形PPS。总的来说，热模型和微观结构的结果证实了由干织物和高温热塑性薄膜制成的层状复合材料的USC工艺的可行性。
Ultrasonic consolidation (USC) of thermoplastic composites is a highly attractive and promising method to manufacture high-performance composites. This work focuses on USC of dry carbon fiber (CF) fabrics with high-temperature polyphenylene sulfide (PPS) films. Experimental trials to assess feasibility of the process are time-consuming. Consequently, a predictive thermal model would facilitate process parameters selection to reduce expensive trial-and-error approaches. This paper presents a 2D finite element model of samples under consolidation, incorporating equations for viscoelastic heating, matrix phase change, and material properties. Theoretical temperature profiles for nodes of interest were compared to the corresponding experimental temperature curves for various control parameters (i.e., weld time and vertical displacement of sonotrode) and showed good agreement during heating phase. It was found that welding time values below 1750 ms were insufficient to reach melting temperature, whereas weld times above 3000 ms led to the lowest average void content (2.43 ± 0.81%). More specifically, the time the material spent above melting temperature, i.e., residence time, was established as a parameter that could estimate cases resulting in better consolidation and lower void content (time above 2600 ms for void content below 2.5%). X-ray diffraction (XRD) characterization revealed that the USC process led to mostly amorphous PPS, due to the high cooling rates (70 °C/s to 108 °C/s). Overall, the thermal model and micro-structural outcomes confirmed the feasibility of the USC process for layered composites made from dry fabric and high-temperature thermoplastic films.