Determination of robust material qualities and processing conditions for laser sintering of polyamide 12
Determination of robust material qualities and processing conditions for laser sintering of polyamide 12
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确定聚酰胺 12 激光烧结的坚固材料质量和加工条件
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
J. Wortberg
中科院分区：
文献类型：
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作者：
A. Wegner;Christoph Mielicki;T. Grimm;Burkhard Gronhoff;G. Witt;J. Wortberg
聚酰胺12（月桂内酰胺）的材料老化是激光烧结（LS）中非常常见的问题。为了稳定的工艺条件，以前工艺中使用的回收材料应使用30-50%的原始粉末材料进行更新。然而，即使遵循这些更新策略，材料质量在几个处理循环之后也下降到不足的水平，这导致在处理时显示出橙子皮或差的机械性能的差的部件质量。为了避免这种情况，建立了质量保证体系，为稳健的工艺条件和材料质量提供建议。对LS中的老化过程进行了详细的研究，比较了两种不同的机器，以分析材料质量，工艺参数和零件性能之间的相关性。允许稳健加工条件的能量输入应在0.325和0.42 J/mm 3之间的范围内，这表明两种机器的值几乎相同。最佳的材料质量范围被认为是机器特定的，而下限位于20和25立方厘米/ 10分钟之间的两台机器使用。此外，材料在烘箱和LS机老化特性进行了比较，为了模拟材料老化在LS过程中，在烘箱中通过简单的实验。
Material aging of Polyamide 12 (Laurinlactam) is a very common problem in laser sintering (LS). For stable process conditions, recycled material used in previous processes should be refreshed with 30–50% virgin powder material. However, even by following these refreshing strategies, material quality drops to an insufficient level after several process cycles which leads to poor part quality showing orange peel or poor mechanical properties when processed. In order to avoid this, a quality assurance system has been established to provide recommendations for robust process conditions and material qualities. A detailed study on aging processes in LS comparing two different machines was performed in order to analyze correlations between material quality, process parameters and part properties. Energy input allowing for robust processing conditions should be in a range between 0.325 and 0.42 J/mm3 showing almost identical values for both machines. Optimal material quality ranges was found to be machine specific, while the lower limit lies between 20 and 25 cm3/ 10 min for both machines used. Additionally, material aging characteristics in an oven and a LS machine were compared, in order to simulate material aging in the LS process by simple experiments in an oven.