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Abstract

Magnetic shape memory effect exhibited by certain alloys at room temperature is known for almost 20 years. The most studied MSM alloys are Ni-Mn-Ga alloys which exhibit up to 12% magnetic field-induced strain (change in shape) depending on microstructure. A multibillion cycle operation without malfunction along with their "smart" properties make them very promising for application in electromagnetic (EM) actuators and sensors. However, considerable twinning stress of MSM crystals resulting in magneto-mechanical hysteresis decreases the efficiency and output force of MSM actuators. Whereas twinning stress of conventional MSM crystals has been significantly decreased over the years, novel crystals with Type II twin boundaries (TBs) possess even lower twinning stress. Unfortunately, the microstructure of MSM crystals with very low twinning stress tends to be unstable leading to their rapid crack growth. Whilst this phenomenon has been studied experimentally, the magnetic field distribution in anisotropic single twin-boundary MSM elements has not been considered yet. This paper analyses the magnetic field distribution in two-variant single twin-boundary MSM elements and discusses its effects on magnetic field-induced stress acting on the twin boundary.

Publication Type:	Conference or Workshop Item (Paper)
Additional Information:	Journal of Physics: Conference Series, vol. 903.
Departments:	School of Science & Technology > Engineering

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