SBIR Phase II: Eddy Current Condition Monitoring of Metallic Flaws Under Surface Coatings Using Giant Magnetoresistance (GMR) Sensors

这个小型企业创新研究(SBIR)二期项目将开发带有GMR和SDT传感器的可现场涡流系统的原型，即使由于热障涂层等原因导致被检查材料出现显著偏离，该系统也可以检测金属中的缺陷。在这个项目中，还将开发在电涡流探头和导电表面之间保持恒定距离的技术，尽管有涂层的介入。这种系统可以用来延长飞机轴承等关键任务部件的寿命，目前必须按相当保守的寿命估计按计划更换这些部件。这些系统的主要商业应用将是军用和商用飞机。一个能够快速扫描区域的简单系统需要涡流探头，可以在一次通过中检测到较大的表面。为该计划开发的GMR和自旋相关隧道(SDT)传感器的紧凑和低功率阵列可用于该应用以及其他应用，如纳米技术读取头，以读取极难妥协的植入磁噪声。对于9/11事件后的世界来说，更安全的身份识别形式的影响是显而易见的。

This Small Business Innovation Research (SBIR) Phase II project will develop prototypes of fieldable eddy-current systems with GMR and SDT sensors that can detect defects in metals even with significant lift off from the material under inspection due to such things as thermal barrier coatings. Techniques for maintaining the a constant distance between the eddy-current probe and the conductive surface despite intervening coatings will also be developed in this project. Such a system can be used to lengthen the lifetime of mission critical components such as aircraft bearings, which at present have to be replaced on schedule using rather conservative lifetime estimates. The main commercial application of these systems would be military and commercial aircraft. A simple system capable of rapidly scanning an area would require eddy-current probes that can inspect a large surface in a single pass. Compact and low-power arrays of GMR and Spin Dependent Tunneling (SDT) sensors developed for this program can be used in this application as well as other applications such as nanotechnolgy read heads to read implanted magnetic noise that is extremely difficult to compromise. The implications for more secure forms of identification are clear for the post 9/11 world.