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Abstract: This research mainly explores the influence of various mixed dielectric fluids on the performance of electrical discharge machining of AISI D2 hardened steels. In this investigation, four types of dielectric fluids such as pure kerosene, kerosene and chromium powder mixed, kerosene and Span‐20 surfactant and the combination of kerosene with chromium powder and Span‐20 surfactant were studied. The obtained results illustrated that the addition of chromium powder and Span‐20 surfactant in the dielectric fluid obtained high material removal rate, low electrode wear rate and good surface finish. The presence of chromium powder will stabilize the gap distance between electrodes which promotes the occurrence of multiple discharges in one input pulse and particle agglomeration is reduced after Span‐20 surfactant molecules cover the surface of debris and carbon dregs in kerosene solution. Combination of kerosene with chromium and Span‐20 surfactant were found significant to improve the effects of carbon accumulation and drag discharge, and reduce unstable concentrated discharge. [ABSTRACT FROM AUTHOR]

It is well known that the magnetic properties of electrical steel sheets are influenced strongly by mechanical stress. We have measured the residual stress distribution with an X-ray stress measurement device and clarified not only the tensile and compressive stress but also the shear stress in a rotating machine core. In particular, the influence of the shear stress on the magnetic properties has not previously been reported. We attempt to develop a new system for measurement of vector magnetic properties under shear stress. This paper presents a mechanism for applying shear stress and the measured vector magnetic properties of nonoriented electrical steel sheet under shear stress. These results indicate that the difference in the vector magnetic properties of the nonoriented electrical steel sheets depended on the shear stress. [ABSTRACT FROM AUTHOR]

Soft devices can be bent, stretched, and compressed reversibly, but conventional wires are rigid. This work describes stretchable composites that are easily fabricated with simple tools and commodity materials, and that can provide a strategy for electrical wiring that meets certain needs of soft devices. These composites are made by combining metal wool and elastomeric polymers. Embedding fine (average fiber width ≈25 μm) steel wool (or other metal wools) in a silicone polymer creates an electrically conductive path through the nonconductive elastomer. This composite is flexible, stretchable, compressible, inexpensive, and simple to incorporate into the bodies of soft devices. It is also electrically anisotropic, and shows maximum conductivity along the majority axis of the fibers, but maximum extension perpendicular to this axis. The utility of this composite for creating an electrically conductive path through an elastomer was demonstrated in several devices, including: a soft, solderless breadboard, a soft touch sensor, and a soft strain gauge. [ABSTRACT FROM AUTHOR]