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[Display omitted] • Gained FeSiCr-based SMCs with a CeO 2 ·SiO 2 composite layer by selective oxidation between substrate and CeO 2 insulation layer. • The CeO 2 insulation layer promotes selective oxidation of Si in substrate during sintering in water vapor environment. • CeO 2 ·SiO 2 composite insulation layer demonstrated a 22.9% reduction in core loss than using the CeO 2 insulating layer alone. • CeO 2 ·SiO 2 composite insulation layer mitigated core loss while maintaining high magnetic conductivity in FeSiCr-based SMCs. This study introduces an approach to fabricating soft magnetic composites (SMCs) that effectively address core loss while maintaining high magnetic conductivity. During the sintering process in a water vapor environment, the CeO 2 insulation layer facilitates the selective oxidation of Si while simultaneously impeding the outward diffusion of Fe and Cr. Consequently, a CeO 2 ·SiO 2 composite insulation layer forms within the FeSiCr-based SMCs. The FeSiCr-based SMCs with the CeO 2 ·SiO 2 composite insulation layer achieve a saturation magnetization of 153.1 emu/g, which is 10.9% lower than that of FeSi 3.7 Cr 4.5 compacts, and exhibits a deterioration rate lower than previously reported values. Moreover, the permeability of the FeSiCr-based SMCs remains highly stable, demonstrating outstanding insulation characteristics. The total core loss and core loss separation results further corroborate that incorporating a CeO 2 ·SiO 2 composite insulation layer leads to a more pronounced reduction in interparticle eddy current loss than using a CeO 2 insulating layer alone. This performance enhancement can be attributed to the selective oxidation of a rare metal oxide insulation layer on a ferromagnetic metal particle substrate, a technique applied to SMCs for the first time. These findings hold significant implications for the design of high-performance SMCs in miniaturized and lightweight electromagnetic devices. [ABSTRACT FROM AUTHOR]

Residual stresses evidently affect the strength, fatigue property and machining deformation of the mechanical components. Therefore, stress relief processes are extensively applied in the manufacturing to enhance the mechanical properties of products. In this study, seven 7075 aluminium alloy specimens are treated by thermal- vibratory stress relief (TVSR), thermal stress relief (TSR), and vibratory stress relief (VSR). Finite element (FE) models considering the stress relaxation effects and transient periodic vibration loads are proposed to simulate the TVSR, TSR and VSR process. The residual stresses before and after the processes are measured and compared, and the effectiveness of the FE models is validated. Scanning electron microscope (SEM) and transmission electron microscope (TEM) are used to observe the microstructure and crystal dislocation, respectively. Results show that TVSR can evidently reduce the residual stress in aluminium alloy, and the stress relief rate of TVSR for the peak stress are 20.43% and 38.56% higher than that of TSR and VSR, respectively. It also found that TVSR has no obvious influence on the grain size, but evidently increase the dislocation density. Eventually, the stress relief mechanism of TVSR is analyzed and summarized. Unlabelled Image • The influences of on the residual stress relief, micro structure, and dislocation density of 7075 aluminium alloy are investigated. • FE models are proposed to simulate the TVSR, TSR and VSR process. • The stress relief rate of TVSR for the peak stress are 20.43% and 38.56% higher than that of TSR and VSR. • TVSR promotes the growth and entanglement of dislocations in the crystals. [ABSTRACT FROM AUTHOR]