ABSTRACT
Induction skull melting (ISM) technology could melt metals with avoiding contamination from crucible. A long-standing problem of ISM is that the low charge energy utilization and inhomogeneous fields have obstructed its application in many critical metal materials and manufacturing processes. The present work investigated the problem through the structure optimization strategy and established a numerical electromagnetic-field model to evaluate components' eddy current loss. Based on the model, the effect of crucible and inductor structure on charge energy utilization, etc. was studied. Furtherly, the charge energy utilization was increased from 27.1 to 45.89% by adjusting the system structure. Moreover, structure modifications are proposed for enhancing electromagnetic intensity and uniformity, charge soft contact and uniform heating. The work constructed a basis for framing new solutions to the problem through ISM device structure optimization.
ABSTRACT
Underwater wireless optical communications (UWOCs) use beam shaping techniques such as the Beer-Lambert (BL) law which describes how light interacts with matter. The BL model ignores the scattering effect of UWOC, while the beam spread function (BSF) can characterize the combined effect of absorption and scattering of UWOC more accurately. The original triple-integral beam spread function (OTI-BSF) involves the Bessel function, which is very time-consuming to calculate. In addition, different seawater environments may require different scattering phase functions (SPFs) to obtain accurate modeling results compared with Henyey-Greenstein SPF (HG-SPF). So far, the BSF-based channel data generation and performance analysis in complex water environments have been time-consuming. We propose a unified simplification of BSF (US-BSF) channel based on the Gaussian mixture model, which is suitable for three commonly used SPFs. From the point of view of time consumption, our proposed US-BSF only requires an order of O(10-4) s to calculate a value on average, while the OTI-BSF requires an order of O(102) s.
ABSTRACT
Herein, the effect of Ni-doping amount on microstructure, magnetic and mechanical properties of Fe-based metallic microwires was systematically investigated further to reveal the influence mechanism of Ni-doping on the microstructure and properties of metallic microwires. Experimental results indicate that the rotated-dipping Fe-based microwires structure is an amorphous and nanocrystalline biphasic structure; the wire surface is smooth, uniform and continuous, without obvious macro- and micro-defects that have favorable thermal stability; and moreover, the degree of wire structure order increases with an increase in Ni-doping amount. Meanwhile, FeSiBNi2 microwires possess the better softly magnetic properties than the other wires with different Ni-doping, and their main magnetic performance indexes of Ms, Mr, Hc and µm are 174.06 emu/g, 10.82 emu/g, 33.08 Oe and 0.43, respectively. Appropriate Ni-doping amount can effectively improve the tensile strength of Fe-based microwires, and the tensile strength of FeSiBNi3 microwires is the largest of all, reaching 2518 MPa. Weibull statistical analysis also indicates that the fracture reliability of FeSiBNi2 microwires is much better and its fracture threshold value σu is 1488 MPa. However, Fe-based microwires on macroscopic exhibit the brittle fracture feature, and the angle of sideview fracture θ decreases as Ni-doping amount increases, which also reveals the certain plasticity due to a certain amount of nanocrystalline in the microwires structure, also including a huge amount of shear bands in the sideview fracture and a few molten drops in the cross-section fracture. Therefore, Ni-doped Fe-based metallic microwires can be used as the functional integrated materials in practical engineering application as for their unique magnetic and mechanical performances.
