Direct writing of continuous carbon fibers/epoxy thermoset composites with high-strength and low energy-consumption
Direct writing of continuous carbon fibers/epoxy thermoset composites with high-strength and low energy-consumption
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DOI：
10.1016/j.addma.2021.102348
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发表时间：
2021-09
影响因子：
11
通讯作者：
Zimeng Zhang;Ruochen Liu;Wei Li;Yuchen Liu;Haochen Luo;Li Zeng;Jingjing Qiu;Shiren Wang
中科院分区：
文献类型：
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作者：
Zimeng Zhang;Ruochen Liu;Wei Li;Yuchen Liu;Haochen Luo;Li Zeng;Jingjing Qiu;Shiren Wang
环氧树脂基热固性复合材料广泛应用于每年收入数十亿美元的行业。高速制造工艺是生产具有几何柔性和低能耗的复杂复合材料结构的非常受欢迎的方法。这项工作演示了印刷和原位固化环氧树脂基热固性材料和复合材料通过自我维持的正面传播。具体地，将树脂制剂中的潜在引发剂从2mol%调整至0.05mol%，以将正面传播温度从约290 °C降低至约240 °C，而不降低反应速率。将环氧树脂浸渍到连续碳纤维（CF）丝束中，然后通过改进的直接墨水书写系统印刷。同步印刷过程和原位正面固化导致连续CF/热固性复合材料（c-CFTC）。使用单喷嘴和双喷嘴打印头来打印具有可调纤维体积分数的c-CFTC。印刷样品表现出优异的拉伸强度，在48体积%的纤维和0.42 GPa在18体积%的纤维在纤维方向和约35.5 MPa的横向方向。还计算了印刷工艺的能耗，与使用数小时高温烘箱固化的传统制造工艺相比，显示出36亿千瓦时（kWh）/年的节能，相当于36万个美国家庭每年的能耗（单个美国家庭的用电量：10，000 kWh/年）。印刷速度为7.5- 13.8cm/min，取决于纤维分数，因此生产速率估计为400-800 cm 3/小时。这种高速率和节能的方法可以彻底改变c-CFTC行业以及航空航天，汽车和海洋行业的环境和能源可持续性。
Epoxy resin-based thermoset composites are extensively used in industries with billions of dollars in revenue every year. High-rate manufacturing process is highly sought-after to produce complex composite structures with geometric flexibility and low energy-consumption. This work demonstrates printing and in-situ cure of epoxy resin-based thermosets and composites via self-sustaining frontal propagation. Specifically, latent initiator in the resin formulation was tuned from 2 mol% to 0.05 mol% to lower the frontal propagation temperature from ~290 °C to ~240 °C without decreasing the reaction rate. The epoxy resin was soaked into continuous carbon fiber (CF) tows and then printed through a modified direct ink writing system. Synchronization of the printing process and in-situ frontal curing resulted in continuous CF/thermoset composites (c-CFTC). Both single and dual nozzle print-heads were used to print c-CFTC with tunable fiber volume fractions. As-printed specimens exhibited exceptional tensile strength, 1.15 GPa at 48 vol% fibers and 0.42 GPa at 18 vol% fibers in fiber direction and ~35.5 MPa in transverse direction. The energy consumption of the printing process was also calculated, indicating 3.6 billion kilowatt-hours (kWh)/year energy-saving in comparison to conventional manufacturing processes with hours of high-temperature oven curing, equivalent to the energy consumption of 360,000 US families per year (single US family electric consumption: 10,000 kWh/year). The printing speed was 7.5–13.8 cm/min dependent on the fiber fraction, and thus the production rate was estimated to be 400–800 cm3/hour. Such a high-rate and energy-saving approach could revolutionize the c-CFTC industry and aerospace, automobile, and marine industries with environmental and energy sustainability.