磁気センサを用いたアルミ部品内部の工具破片検出

抄録

A thin-film magnetic field sensor is useful for detecting foreign matters included in industrial and medical products. It can detect a small piece of tool steel chip or breakage inside the products nondestructively. An inspection of all items in the manufacturing process is desirable for the smart manufacturing system. The thin film magneto-impedance sensor is useful for detecting a magnetic material nondestructively using a strong magnetic field. The sensor made by single layer amorphous thin film has a tolerance against surface normal magnetic field because of its demagnetizing force in the thickness direction. A proposal of nondestructive inspection system for how detecting a contaminant of small tool steel chip in aluminum casting specimen had been carried out. A prototype system was fabricated and experimentally showed a detection of low remanence magnetic contaminant in a bulk aluminum casing specimen. A method of numerical estimation of contaminant position in bulk work piece is also proposed.