Development of Supersonic Interference VSM for detecting initial degradation on Nickel based Alloy

提出了一种新的磁性无损检测方法——超声干涉VSM，用于镍基合金的初始降解检测。该测量方法是基于在原始合金无磁性的情况下，降解区表现出微小的磁性。实验结果表明，用实验装置测量了两种不同频率的超音速波交点处微小磁性材料的磁性能。此外，利用蒙特卡罗方法模拟了磁化过程与降解区周围小磁性材料分布的关系。仿真结果表明，剩磁和矫顽力与降解程度有较好的对应关系。结果表明，超声速干涉VSM有可能成为一种非常有用的新型无损评价方法。

A new magnetic non-destructive evaluation method named as a supersonic interference VSM was developed for detecting initial degradation on Nickel based alloy, which is widely used as structural materials. The measurement method is based on the fact that degradation area shows tiny magnetic property, although original alloy has no magnetism. As the experimental results, the magnetic properties of tiny magnetic materials were measured at the cross points of two supersonic waves which have different frequencies by a trial equipment.Moreover, magnetization processes depending on the distribution of small magnetic materials around degradation region were simulated by Monte Carlo method. The simulation results show the magnetic remanence and coercivity are good correspondences with degradation degrees.The results show the hopeful possibility that the supersonic interference VSM becomes a very useful tool as a new non-destructive evaluation method.