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The metal magnetic memory (MMM) technique relies on the measurement of stress-induced self-magnetic leakage fields (SMLFs) at the stress concentration zones (SCZs) of ferromagnetic materials during mechanical loading. However, there is an associated change in geometry of the specimen along with the stress due to plastic deformation. This paper presents a three-dimensional finite element (3D-FE) analysis of the stress-induced geometry effect on SMLFs in notched specimens during tensile deformation. The tangential (Hx) and normal (Hy) components of the SMLF signals have been predicted from the deformed specimens caused by different levels of tensile stress. Key parameters from the SMLF signals are determined for the possible estimation of damage in the specimen under tension. Studies reveal that the stress-induced geometry effect has a great influence (about 20%) on the SMLF signals, especially in the plastic deformation stage. The results show that the peak amplitude could be used for the estimation of different deformation stages under tension. The study also reveals that the SMLF signal is influenced by the thickness of the tensile specimen. The model-predicted thickness profile has also been experimentally validated.
We report a two-step process for the immobilization of gold nanocubes (Au-NCs) on a glass surface using a combination of extraction and exchange reaction using poly (sodium 4-styrenesulfonate) (PSS) and trisodium citrate (TSC). Cetyltrimethylammonium chloride (CTAC) stabilized gold nanocubes (CTAC/Au-NCs) synthesized by a microfluidic synthesis procedure were successfully deposited on silane-modified glass substrate after extraction of excess CTAC using chloroform followed by exchange of CTAC to TSC on the surface of Au-NCs. Further, TSC/Au-NCs were found to be highly stable and suitable for microfluidic sensing of different glucose concentrations using localized surface plasmon resonance (LSPR) spectroscopy offering an improved sensitivity (126.37 nm/RIU).
Shape memory alloy structures for actuator and vibration damper applications may be manufactured using wire arc additive manufacturing (W AAM), which is one of the additive manufacturing technologies. Multilayer deposition causes heat accumulation during W AAM, which rises the preheat temperature of the previously created layer. This leads to process instabilities, which result in deviations from the desired dimensions and mechanical properties changes. During W AAM deposition of the wall structure, a systematic research is carried out by adjusting the interlayer delay from 10 to 30 s. When the delay period is increased from 10 to 30 s, the breadth decreases by 45% and the height increases by 33%. Grain refinement occurs when the interlayer delay duration is increased, resulting in better hardness, phase transformation temperature, compressive strength, and shape recovery behavior. This study shows how the interlayer delay affects the behavior of W AAM-built nickel-titanium alloy (NiTi) structures in a variety of applications.