Abstract
In plastic forming, deformation resistance of a material is generically decreased by superimposed ultrasonic vibrations as "Blaha effect". The mechanism of these effects is not cleared entirely. Moreover, there are not many studies for the superimposed ultrasonic vibration technique on tensile and compressive test using several alloys. It is necessary to clear the mechanism of the stress decreasing owing to ultrasonic vibration technology. Therefore, in this study, the stress-strain curves of (AZ31) magnesium alloy were obtained superimposed ultrasonic vibrations on tensile and compression tests. As a result, the effect of superimposed ultrasonic vibrations on compression test was confirmed. the compression stress decreased pronouncedly. On the other hand, superimposed ultrasonic vibrations on tensile test is not so much stress decreasing as compared with compression test.
