In the present research, rapidly solidified Fe85. 3 B11 P3 Cu0. 7 ribbons were prepared by melt spinning process. The microstructural variation, as well as magnetic properties of the as-spun and annealed ribbons, were characterized by X-ray diffraction (XRD), transmission Mossbauer spectroscopy and alternating gradient field magnetometer (AGFM). The results showed two separated distinct exothermic peaks during heating, resulting from the phase tran-sition from amorphous to α-Fe and then to Fe3 B, respectively. The study of magnetic properties in the amorphous and nanocrystalline states revealed that annealing the amorphous ribbons at 440˚ C for 10 minutes gives rise to a significant increase in saturation magnetization (220 emu/g) which makes this alloy a good candidate for power applications.

The effect of length variation on the magnetic properties of NiFe alloy nanowires electrodeposited into the alumina template was investigated. The diameter (45±2.5 nm) and length (~1.9, 7.12, 8.3, 9.5 and 13.3mm) of the nanowires were estimated from scanning electron microscopy images. Energy dispersive spectroscopy results showed Ni3Fe7 composition of the alloy nanowires. The magnetic properties of the samples were investigated by vibrating sample magnetometer. It showed that with increasing the length of the nanowires from 1.9±0.1mm to 13.3±0.66mm, coercivity reduced from 1050 Oe to 705 Oe and squareness reduced from 0.64 to 0.46. The results proved increasing the magnetostatic interaction between the nanowires with length. Progress toward the multi-domain behavior was predicted caused to drastically reduce in the coercivity.

In the current study, nanocrystalline Finemet soft magnetic cores were processed and their thickness was improved by the hot pressing technique. Besides, the effect of hot pressing on the microstructure and soft magnetic properties of the amorphous precursor was compared with the conventional annealing method. First, amorphous Finemet ribbons were produced through the melt-spinning method. Thermal behavior of the amorphous Finemet ribbons and crystallization of the anocrystalline phase was studied by Differential Scanning Calorimetry. Thus, the proper crystallization temperature of the amorphous phase was specified about 550oC. To crystallize the nanocrystallime phase from the amorphous matrix, the produced ribbons were either annealed conventionally at 550oC for 30 min or hot pressed at the same temperature for 60 min, under a controlled H2/Ar atmosphere, a 30% H2, 70% Ar mixture. The formed phases were specified by X-ray diffraction, and microstructure of the formed alloy was evaluated by scanning electron microscopy. It was shown that, both methods result in the formation of a-FeSi nanocrystals embedded in an amorphous matrix. The average size of the formed a-FeSi nanocrystals was calculated by using the MAUD software, came out to be 17 and 12 nm, for annealed and hot pressed samples, respectively. Hence, hot pressing results in crystal size reduction, compared with the conventional annealing method. Moreover, this processing method can decrease the soft magnetic properties of the amorphous precursor. However, the produced cores exhibit good soft magnetic properties (Hc~ 8 Oe, δ~130 emu/g).

Soldering plays a crucial role in the electronics industry, driving the need for constant improvements in physical and mechanical properties and the management of intermetallic compound formation. Research in composite materials aims to achieve a uniform distribution of reinforcing particles within solder matrix to enhance their performance. This study investigates the integration of cobalt microparticles into SAC0307 lead-free soft solder alloy using the accumulative roll bonding (ARB) method. Microstructural analysis confirmed a homogeneous dispersion of cobalt particles within the solder after three ARB passes. Moreover, increasing cobalt content led to a reduction in the size of Cu6Sn5 intermetallic compounds, from 9 µm to 5 µm with 1% cobalt by weight. Examination of β-Sn grain morphology revealed the impact of cobalt particles on recovery and recrystallization kinetics in the solder. Mechanical testing indicated a 20% decrease in interlayer strength within composite solder sheets. Tensile tests showed a 28% increase in strength and a 31% decrease in elongation for composite solder alloy containing 1% cobalt. Differential scanning calorimetry (DSC) results revealed minimal change in the melting temperature of composite solder foil.

In this research, Alnico 5DG alloy was melt and cast in the optimum conditions and its samples were homogenised and heat treated in a magnetic field in order to obtain the required magnetic properties. Microstructure, phase composition and magnetic properties of samples were examined in every processing step. The results indicated that the properties of samples were highly influenced by processing parameters. A proper microstructure composed of α1 magnetic phase in a texture of α2 with acceptable magnetic properties was obtained by meticulous control of the processing conditions. The results also revealed that the magnetic coercivity (and remanence) of the cast samples should be increased by an appropriate heat treatment from 12 kA/m (and 0.55 T) to 41.6 Wm (and 1.3 T), respectively.

This study presents critical buckling of functionally graded soft ferromagnetic porous (FGFP) rectangular plates, under magnetic field with simply supported boundary condition. Equilibrium and stability equations of a porous rectangular plate in transverse magnetic field are derived. The geometrical nonlinearities are considered in the Love- Kirchhoff hypothesis sense. The formulations are compared to those of homogeneous isotropic plates were given in the literature. In this paper the effect of pore pressure on critical magnetic field of plate and the effect of important parameters of poroelastic material on buckling capacity are investigated. Also the compressibility of fluid and porosity on the buckling strength are studied.

Co-Cr films were produced with electrodeposition with different pH at room temperature. The effect of electrolyte pH on the structural, surface morphology and magnetic properties of the films was studied. X-ray diffraction measurement showed that the films have hexagonal close packed structure. For the films deposited at different pH values, the surface morphologies with different-sized globular granules were observed whereas the morphology covered by uniformly distributed nanoscale grains was detected for the surfaces of all films produced from electrolytes with different Cr concentrations. Magnetic properties such as coercivity and saturation magnetization showed strong dependence on the electrolyte solution pH and consequently the crystallite size. The Co-Cr films with low Hc were achieved using relatively low electrolyte pH. The differences observed in the magnetic properties were attributed to the structural changes caused by the electrolyte pH. The Co-Cr films may have the potential applications in magnetic recording and sensors technologies.

The soft magnetic nanocrystalline Fe73.5Si13.5B9Cu1Nb3 alloy (FINEMET Ò) is produced by heat treatment of amorphous precursor. Determining kinetic parameters of amorphous structure transformation to nanocrystalline allows the control of microstructure (e.g. size and volume fraction of nanocrystalline grains) in order to achieve desired soft magnetic properties by optimizing the heat treatment conditions. In this research, the nanocrystallization kinetics of amorphous FINEMET alloy were studied using isoconversional and isokinetic methods under non-isothermal conditions of various heating ratesranging from 5 to 20oC/min. The changes in the microstructure and magnetic properties of amorphous ribbon during nanocrystallization process were studied using X-ray diffractometry and hysteresisgraph, respectively.

This paper proposes a new inexpensive soft force sensor suitable for soft robotics applications that require high flexibility and wide range of sensing area. All Hall Effect sensors developed so far use a Hall Effect sensor to detect the magnetic field of a piece of solid magnet. The proposed force sensor in this paper uses a Hall Effect sensor to detect the magnetic flux density change induced by aligned magnetic powder blended with silicone rubber when a normal force is applied. The sensor is designed and tested with different magnetic powder density and sensor dimensions to achieve an optimum design in sensitivity as well as linearity. The experimental results show that different force measurement range with specific desired sensitivity can be achieved by adjusting certain physical properties of the sensor.This is a useful feature for many soft sensing elements in today's applications requiring more compliance and reliable sensors, especially in soft robotics applications.