量化残留方向和热应力对聚乙烯材料挤出中的双断率的贡献
Anthony P Kotula1, Benjamin E Dolata1, Yoontae Kim1,2,3
1Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
Additive manufacturing
|February 19, 2025
概括
这项研究用双折射成像在3D打印的多聚化物中量化了剩余链的方向. 较低的温度和更快的速度增加了接区附近的方向,影响了机械性能.
科学领域:
- 增材制造 增材制造 增材制造
- 聚合物科学 聚合物科学
- 材料科学 材料科学 材料科学
背景情况:
- 与注塑成型相比,材料挤出3D打印往往会产生较弱的部件,特别是在层间的接区域.
- 3D打印零件的故障通常归因于链条的方向和线上的残余应力.
- 量化剩余链方向对于理解和改进3D打印聚合物的机械性能至关重要.
研究的目的:
- 为了在3D打印的多聚化物中空间描述残余应力和链条方向.
- 为了研究印刷条件对双折度的影响,测量链条方向和应力.
- 为了区分压力诱导和定向诱导的双断,并探索放松方法.
主要方法:
- 使用双折射成像与延迟和样品厚度测量相结合.
- 分析了印刷和冷却的多聚化物样本中双折度的空间变化.
- 与打印参数 (喷嘴温度,打印速度) 和回火处理相关的双断率.
主要成果:
- 作为打印的聚乙烯呈现出均的双断层背景,在接区附近的价值较高,特别是在较低的喷嘴温度和更快的打印速度下.
- 双重违规性归因于剩余链的方向和不均的冷却引起的剩余应力.
- 在65°C的火缓解了剩余应力,同时保持了基于方向的双断,表明不同的起源.
结论:
- 双断层成像有效量化3D打印聚合物中的残余链方向和应力.
- 打印条件显著影响剩余链方向的大小和分布.
- 这些发现为优化3D打印工艺提供了一条途径,通过管理残余应力和链条方向来提高机械性能.
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