In this paper, the radio frequency (RF) magnetron sputtering (MS) method was utilized to fabricate multiple sets of the iron film samples under different sputtering powers. With the help of X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and vibrating sample magnetometer (VSM), how the sputtering power affected the structure, morphology and magnetic properties of the iron film was studied. XRD results showed that all Fe films have a polycrystalline bcc structure and (110) preferred orientation. According to the Bragg equation calculation, the larger the sputtering power, the larger the average grain size, which is consistent with the results of AFM particle size analysis. The main reason is that the sputtering power affects the grain growth mode. As the sputtering power increases, it gradually changes from a small island-like growth to a thick columnar growth. However, from the surface morphology and height profile, we saw that the iron film deposited under 230 W had the most uniform grain size distribution and the grain size was relatively small. This is why thin films deposited under this condition have the best soft magnetic properties. The saturation magnetization (Ms) reaches 1566 emu/cm³, coercivity (Hc) is 112 Oe, and squareness ratio (Mr/Ms) is 0.40. Therefore, iron film prepared under 230 W has good comprehensive properties (highest Ms, lower Hc and Mr/Ms) that provide an experimental basis for further thin film research work.

This paper presents a comprehensive investigation of the phase and microstructure, the thermodynamic behavior within the molten pool, and the growth mechanism of in situ oxide dispersion-strengthened (ODS) aluminum-based composites processed by a selective laser melting (SLM) additive manufacturing/3D printing process. The phase and microstructure were characterized by X-ray diffraction (XRD) and a scanning electronic microscope (SEM) equipped with EDX, respectively. The thermodynamic behavior within the molten pool was investigated for a comprehensive understanding on the growth mechanism of the SLM-processed composite using a finite volume method (FVM). The results revealed that the in situ Al₂Si₄O₁₀ ODS Al-based composites were successfully fabricated by SLM. Combined with the XRD spectrum and EDX analysis, the new silica-rich Al₂Si₄O₁₀ reinforcing phase was identified, which was dispersed around the grain boundaries of the aluminum matrix under a reasonable laser power of 200 W. Combined with the activity of Marangoni convection and repulsion forces, the characteristic microstructure of SLM-processed Al₂Si₄O₁₀ ODS Al-based composites tended to transfer from the irregular network structure to the nearly sphere-like network structure in regular form by increasing the laser power. The formation mechanism of the microstructure of SLM-processed Al₂Si₄O₁₀ ODS Al-based composites is thoroughly discussed herein.

An iron-based soft magnetic composite with Fe₃O₄-MnZnFe₂O₄ insulation coating has been prepared by powder metallurgy method. This work investigated the microstructure and magnetic properties of Fe/Fe₃O₄-MnZnFe₂O₄ powder cores. Scanning electron microscopy (SEM) coupled with an energy dispersive spectrometry (EDS) analysis indicated that the Fe₃O₄ and MnZnFe₂O₄ nanoparticles were uniformly coated on the surface of Fe powders. The co-existence of Fe₃O₄ and MnZnFe₂O₄ contributes to the preferable distribution of nano-sized insulation powders and excellent soft magnetic properties of soft magnetic composite (SMC) with high saturation magnetization M_s (215 A·m²/kg), low core loss (178.7 W/kg measured at 100 kHz, 50 mT), and high effective amplitude permeability of 114 (measured at 100 kHz). Overall, this work has great potential for realizing low core loss and outstanding soft magnetic properties of Fe-based powder cores.

In this paper, aluminum alloy samples were fabricated by selective laser melting (SLM) and subsequently T2 heat treatment was undertaken. In order to obtain comprehensive results, various experiments on densification, hardness, tensile strength, bending strength and microstructure characterization were carried out. The results show that densification of samples after T2 heat treatment does not vary very much from the SLMed ones, while the Brinell hardness and strength decreases to about 50%. Moreover, the plasticity and fracture deflection increases about 3 fold. The effects on the microstructure and the mechanical properties of the SLMed aluminum alloy samples and subsequent T2 heat treatment were studied.

The Fe-Si/MnZn(Fe₂O₄)₂ composite powders are synthetized by means of the mechanical milling, and Fe-Si/MnZn(Fe₂O₄)₂ soft magnetic composites are prepared by spark plasma sintering (SPS). The impact of milling time on particle size, phase structure and magnetic properties of the investigative core-shell structure powders along with that of sintering temperature on microstructure and magnetic properties of FeSi-MnZn(Fe₂O₄)₂ soft magnetic composite are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The experimental results demonstrate a layer of MnZn(Fe₂O₄)₂ forming a coating on the surface of Fe-Si powder after mechanical milling, and the soft magnetic composites exhibiting excellent magnetic performance at 900 °C: 212.49 emu/g for saturation magnetization, with 6.89 Oe for coercivity, 3 × 10⁻⁴ Ω.m for electrical resistivity and stable amplitude permeability and low core loss over a wide frequency range. Therefore, SPS offers a convenient and swift way to enhance performance of soft magnetic composites using magnetic materials as insulting layer.