大尺寸增材制造中的工艺-结构-属性关系发展:纤维对齐和最终拉力强度
Lucinda K Slattery1,2, Zackery B McClelland1, Samuel T Hess2
1Engineer Research and Development Center, U.S. Army Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, MS 39180, USA.
Materials (Basel, Switzerland)
|April 13, 2024
概括
增材制造 (AM) 部件表现出机械异质性. 在聚合物挤出中增加挤出速率会减少纤维对齐,并改善碳纤维增强PLA的最终抗拉强度 (UTS) 一致性.
科学领域:
- 材料科学 材料科学 材料科学
- 制造业 工程 制造工程
- 聚合物科学 聚合物科学
背景情况:
- 增材制造 (AM) 通常会导致印刷零件的机械异构性.
- 聚合物材料挤出 (MEX) 零件在层接口上表现出弱点.
- 纤维对齐显著影响复合AM部件的机械性能.
研究的目的:
- 研究大型MEX零件的挤出速度,纤维对齐和最终抗拉强度 (UTS) 之间的关系.
- 开发和验证用于量化3D打印复合材料中的纤维对齐的方法.
- 为了建立增材制造的工艺结构和属性关系.
主要方法:
- 用切碎的碳纤维打印的聚乳酸) 使用大尺寸颗粒打印机以不同的挤出速度打印.
- 使用X射线显微镜 (XRM) 来重建内部微观结构并分析纤维的长度和方向.
- 使用图像分析技术来确定相对于沉积方向的纤维对齐.
- 进行了拉力测试,以测量最终拉力强度 (UTS).
主要成果:
- 无论是XRM 3D对象分析还是离散图像分析,都显示了挤出速率和纤维对齐之间的负相关性.
- 较高的挤出速度导致纤维对齐度下降,每个挤出乘数的斜率分别为-34.64%和-53.43%.
- 增加挤出乘数减少了UTS的变化,最小百分比差异为8.12 ± 14.40%.
结论:
- 挤出率是影响MEX中纤维对齐的关键参数.
- 图像分析提供了一种可行的方法,用于在AM部件中将微观结构与 meso-properties 相对应.
- 该研究建立了大型增材制造的关键过程结构和属性关系.
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