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This article presents a novel rotary magnetorheological fluid device with inherently low off-state torque. The working principle of the device is similar to peristaltic pumps except the fluid remains inside the device and circulates continuously. Unlike other continuous rotation magnetorheological fluid devices, which operate in shear mode, the proposed device works in pressure driven flow mode. A proof of concept prototype with arbitrary dimensions is built and experimentally evaluated. Measured off-state torque is as low as 20 N.mm. Analytical model of the resistant torque and finite element simulations of the magnetic circuit are presented and validated with the experimental results. Using these models, an optimal device with similar off-state characteristics can be designed to fulfill specific requirements of size, weight, power and on-state torque. The proposed concept is promising especially for use in high precision haptic interfaces that require stability and transparency at the lower end of force spectrum.

& Dual phase steel has become an important engineering material to be used in structural and automotive applications due to its good combination of strength, ductility, and formability. In this study, hardenability of a low carbon and microalloyed steel was investigated by using the standard Jominy End Quench Test at four different quenching temperatures. Three steel specimens were quenched from the intercritical region at 737 C, 754 C, and 779 C separately, whereas one of them was tested at 900 C, in the fully austenitic region. After finishing the Jominy test, metallographic examination of the samples was carried out to see the variation in the microstructure through the length of the steel. And also, hardness measurements were made through the length of the samples. Results brought out that there was a strong decrease in the hardness of the tested samples after a depth of 5 mm from the quenched end.

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