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In order to investigate the formation mechanism of alumina particles in early stages of Al-deoxidation reaction, the samples are prepared by Al-deoxidation for Fe-O (90 ppm) melt in confocal laser scanning microscope (CLSM). The shapes of alumina inclusions are irregular in various samples, and their equivalent radius is between 15 and 150 nm based on the observation of field emission scanning electron microscope (FESEM) with energy dispersive spectrometer (EDS). The size and number density of alumina inclusions increase with the increase of temperature of deoxidation while decrease with the increase of cooling rate. Based on the EDS results and Fe-Al phase diagram, it is found that the Al-deoxidation reaction zone is mainly composed of the FeAl, Fe 2 Al 5 , and FeAl 3 phase. The average size of alumina particles in the FeAl phase are larger than that of in the Fe 2 Al 5 phase. Alumina particle is not observed in the FeAl 3 phase by FESEM. The observation and estimation based on the growth mechanisms of inclusions indicate that the growth of nanoscale alumina with large size is controlled by the diffusion growth and Brownian collision in high temperature melt, while nanoscale alumina with small size are secondary precipitate phase in the process of solidification.

Herein, the precipitation of TiS in an Al–Ti simultaneously deoxidized steel is observed, and the results confirm the precipitation of single TiS, two‐layered oxide (Al2O3 or TiOx)–TiS composite, and three‐layered Al2O3–TiOx–TiS composite inclusions in the steel. Thermodynamic calculations reveal that TiS precipitated in the experimental steel during the solidification process when the solid fraction (xs) is 0.880. In addition, the precipitation of TiOx during solidification depends on the equilibrium partition of O. When the O content in steel is very low, TiS rather than TiOx is precipitated. In addition, the enrichment of O in the residual liquid steel results in the precipitation of TiOx during the solidification process. Oxide–TiS is formed by TiS precipitation on the surface of Al2O3 and TiOx precipitation in the liquid steel or at the initial stage of solidification. However, Al2O3–TiS is formed only in preformed solid steel with low oxygen content. The lattice misfit results suggest that it is easier to match TiS to TiO and TiO2, while the misfit of TiS(001)/bcc Fe(100) is 6.06.

Magnesium–lithium alloy is the lightest metal alloy material so far, and the ultra-thin plate is also one of the main trends in the future development of Mg-Li alloy. In order to explore how to prepare LZ91 ultra-thin Mg-Li alloy, this topic adopts the combination of the finite element method (FEM) and visco-plastic self-consistent (VPSC) calculation, electron back-scattered diffraction (EBSD) and tensile experiment, and uses the asymmetric warm rolling process to realize the processing of ultra-thin LZ91 Mg-Li alloy plate with a thickness of 0.25 mm. The experimental results show that the maximum basal texture strengths of 1 mm initial plate and 0.25 mm ultra-thin rolled plate are 36.02 mud and 29.19 mud, respectively. The asymmetric warm rolling process not only reduces the basal texture strength but also significantly refines the grains. The tensile strength and yield strength of 0.25 mm ultra-thin rolled plate along the rolling direction reached 206.8 MPa and 138.4 MPa, respectively. This has a positive effect on the mechanical properties of subsequent materials. VPSC results show that the base slip is the main factor in Mg-Li alloy asymmetric warm rolling, and a large number of tensile twinning are initiated due to the coordinated deformation of the body-centered cubic (BCC) phase, which is beneficial to improve the plastic deformation capacity of Mg-Li alloy.

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