Impedance-based non-destructive evaluation of additively manufactured parts
Impedance-based non-destructive evaluation of additively manufactured parts
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DOI：
10.1108/rpj-03-2016-0046
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发表时间：
2017-01-01
影响因子：
3.9
通讯作者：
Tarazaga, Pablo A.
中科院分区：
文献类型：
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作者：
Albakri, Mohammad I.;Sturm, Logan D.;Tarazaga, Pablo A.
目的：本工作提出利用机电阻抗测量作为增材制造（AM）的无损评估（NDE）手段。研究了该技术对增材制造中常见的各种缺陷类型的有效性和灵敏度。设计/方法/方法-为了评估基于阻抗的增材制造NDE的可行性，作者首先设计并制造了一套具有典型增材制造过程构建误差的测试样品，包括尺寸不准确性、位置不准确性和内部孔隙度。本文研究了两种聚合物增材制造工艺：材料喷射和挤压。然后对所有部件进行基于阻抗的分析，并在监督学习环境中用于识别缺陷部件。新提出的基于阻抗的无损检测技术已被证明是检测几种打印缺陷的有效解决方案。具体来说，研究表明，该技术能够检测挤压尼龙部件和喷射VeroWhitePlus部件中导致质量变化（小至1%）和特征位移（小至1毫米）的打印缺陷。内部孔隙缺陷也可以检测到；然而，这种缺陷类型对测量阻抗的影响并不像尺寸和位置误差那样深刻。独创性/价值——与目前可用的无损检测技术相比，新提出的基于阻抗的无损检测技术是一种基于功能的技术，具有成本效益高、灵敏度高、适合检测复杂几何形状和深埋缺陷的增材制造零件的优点。这项技术有可能弥合当前无损检测实践中的现有差距，从而为更广泛地采用增材制造来生产关键任务部件铺平道路。
Purpose - This work proposes the utilization of electromechanical impedance measurements as a means of non-destructive evaluation (NDE) for additive manufacturing (AM). The effectiveness and sensitivity of the technique for a variety of defect types commonly encountered in AM are investigated.Design/methodology/approach - To evaluate the feasibility of impedance-based NDE for AM, the authors first designed and fabricated a suite of test specimens with build errors typical of AM processes, including dimensional inaccuracies, positional inaccuracies and internal porosity. Two polymer AM processes were investigated in this work: material jetting and extrusion. An impedance-based analysis was then conducted on all parts and utilized, in a supervised learning context, for identifying defective parts.Findings - The newly proposed impedance-based NDE technique has been proven to be an effective solution for detecting several types of print defects. Specifically, it was shown that the technique is capable of detecting print defects resulting in mass change (as small as 1 per cent) and in feature displacement (as small as 1 mm) in both extruded nylon parts and jetted VeroWhitePlus parts. Internal porosity defects were also found to be detectable; however, the impact of this defect type on the measured impedance was not as profound as that of dimensional and positional inaccuracies.Originality/value - Compared to currently available NDE techniques, the newly proposed impedance-based NDE is a functional-based technique with the advantages of being cost-effective, sensitive and suitable for inspecting AM parts of complex geometry and deeply embedded flaws. This technique has the potential to bridge the existing gaps in current NDE practices, hence paving the road for a wider adoption of AM to produce mission-critical parts.