Manufacture of magnetic scaling rod with transformation-induced plasticity

Intelligent actuators have contributed to constructing products such as machines, robotic systems and to factory automation. The stroke is measured by using a sensor located on one end of an actuator. This stroke sensing system is not only very complex but also sensitive to vibration, dust and fumes. To solve this problem, a new actuator has already been developed. This actuator's piston rod has highly accurate magnetic scales made by laser beam irradiation. This allowed the development of a scaling rod, which satisfies both accuracy and intensity. Manufacturing cost is, however, very high, and the applications are restricted to special use. Therefore, the purpose of this paper is the development of a new manufacturing process with plastic forming in order to improve productivity. In this method, magnetic scales are made by rotary forming. Only the plastic deformation parts become ferromagnetic because of transformation-induced martensite by transformation-induced plasticity (TRIP) effect on the surface of a nonmagnetic rod. Using this method, a reasonable and accurate regular magnetic interval and the stroke's high degree of accuracy is achieved.