Teliban I, Thede C, Chemnitz S, Bechtold C, Quadakkers W J, Schütze M, Quandt E
Institut für Materialwissenschaften, Christian-Albrechts-Universität zu Kiel, Kaiserstr. 2, 24143 Kiel, Germany.
Rev Sci Instrum. 2009 Nov;80(11):115106. doi: 10.1063/1.3248359.
Gas turbines and other large industrial equipment are subjected to high-temperature oxidation and corrosion. Research and development of efficient protective coatings is the main task in the field. Also, knowledge about the depletion state of the coating during the operation time is important. To date, practical nondestructive methods for the measurement of the depletion state do not exist. By integrating magnetic phases into the coating, the condition of the coating can be determined by measuring its magnetic properties. In this paper, a new technique using frequency mixing is proposed to investigate the thickness of the coatings based on their magnetic properties. A sensor system is designed and tested on specific magnetic coatings. New approaches are proposed to overcome the dependency of the measurement on the distance between coil and sample that all noncontact techniques face. The novelty is a low cost sensor with high sensibility and selectivity which can provide very high signal-to-noise ratios. Prospects and limitations are discussed for future use of the sensor in industrial applications.
燃气轮机和其他大型工业设备会遭受高温氧化和腐蚀。高效防护涂层的研发是该领域的主要任务。此外，了解涂层在运行期间的损耗状态也很重要。到目前为止，尚不存在用于测量损耗状态的实用无损方法。通过将磁性相整合到涂层中，可以通过测量其磁性来确定涂层的状况。本文提出了一种利用频率混合的新技术，基于涂层的磁性来研究涂层厚度。设计了一种传感器系统并在特定磁性涂层上进行了测试。提出了新的方法来克服所有非接触技术都面临的测量对线圈与样品之间距离的依赖性。其新颖之处在于一种低成本、高灵敏度和高选择性的传感器，它可以提供非常高的信噪比。讨论了该传感器在工业应用中的未来使用前景和局限性。
