Yi Yang

A novel Al‐Ti‐B‐Cr‐Ce master alloy refiner with anti‐Si‐poisoning and fading effect was developed through co‐doping with chromium (Cr) and cerium (Ce). Al ₂₀ Ti ₂ Ce phase in Al‐3Ti‐1B‐0.5Cr‐0.8Ce intermediate alloys can significantly refine the dendrite arms of α ‐Al. The rare earth phase serves as an effective protective shell, which not only inhibits the aggregation and growth of the Al ₃ Ti phase but also reduces the surface energy and agglomeration tendency of the TiB ₂ phase. A small amount of chromium can form CrB ₂ with B and also form the Al ₁₃ Cr ₄ Si ₄ phase, enhancing the anti‐poisoning effect during the refinement process and having a significant refining effect on the Si phase. The incorporation of an Al‐3Ti‐1B‐0.5Cr‐0.8Ce master alloy into A356 aluminum alloy yields significant grain refinement. Notably, the refined grain size can be sustained below 150 µm even after 120 min of holding. Furthermore, the refined alloy exhibits enhanced mechanical properties, tensile strength augmented by 28.7% to 215 MPa, yield strength elevated by 37.0% to 185 MPa, and elongation at break enhanced by 19.1% to 9.82%.

Ion implantation technology is a crucial strategy for modulating the degradation behavior of biomedical magnesium alloys. In this study, Ag, Ti, and Zr ions were implanted into the surface of pure Mg at varying doses to investigate their effects on the microstructure and properties of pure Mg. The results revealed that differences in the affinities of Mg and the implanted elements for reacting with oxygen led to the formation of implanted layers with distinct compositions and structures. Specifically, Ag ion implantation resulted in a layer predominantly composed of elemental silver, while Ti and Zr ion implantation promoted the formation of a denser layer containing Mg, MgO, the implanted elements, and their respective oxides. This layer significantly enhanced the corrosion resistance of pure Mg by reducing its susceptibility to corrosive media. Electrochemical assessments showed a substantial reduction in corrosion current density following Ti and Zr ion implantation. However, increasing doses of Ag ions induced heightened susceptibility to galvanic corrosion due to the electrode potential differences between Ag and Mg, thereby accelerating the degradation of the pure Mg substrate. Additionally, first‐principles calculations of the work functions for both the (0001) basal plane and the prism plane of Mg corroborated the observed electrochemical trends.

The durability performance in molten aluminum with high chemical activity is considered to be a crucial factor for the application of traditional ceramic‐matrix composites in the aluminum industry. Herein, novel Ti(C, N) cermet composites with excellent corrosion resistance, featuring distinct ratios of high‐entropy alloy binders, were meticulously synthesized by spark plasma sintering (SPS). The synergetic effect of porosity and binder on the corrosion resistance was detailed analyzed. The results show that 8 wt% binder provides an optimum balance of porosity, hardness, fracture toughness and corrosion resistance of the cermets. The appealing corrosion resistance is intimately associated with the formation of a continuous layer consisting of TiN/AlN, which is introduced through the decarburization of the Ti(C, N) cermets. Additionally, a corrosion mechanism is proposed to elucidate the formation of alternating morphologies within the reaction layers of the cermets. This work is beneficial for selecting structural materials for use in the aluminum industry.

In this study, five kinds of (Zr_0.2Ta_0.2Ti_0.2Cr_0.2Hf_0.2)Si₂ high-entropy ceramics were prepared by a two-step method under different vacuum pressureless pre-sintering processes, and the microstructures and mechanical properties of the ceramics under different parameters of the pre-sintering process were systematically discussed. The results show that the physical structure of the ceramic samples remains basically unchanged by changing the pre-sintering conditions; the longer the holding time of the initial pre-sintering, the higher the densification of the samples and all of them are above 95%. The hardness of the ceramics was around 10 GPa, with the best hardness of 10.11 GPa at 1300 °C for 3 h. This conclusion provides data support for the optimization of the high-entropy ceramics preparation process.

During the hot dip aluminum plating process, components such as sinking rollers, pulling rollers, and guide plates will come into long-term contact with high-temperature liquid aluminum and be corroded by the aluminum liquid, greatly reducing their service life. Therefore, the development of a material with excellent corrosion resistance to molten aluminum is used to prepare parts for the dipping and plating equipment and protect the equipment from erosion, which can effectively improve the production efficiency of the factory and strengthen the quality of aluminum-plated materials, which is of great significance for the growth of corporate profits. With AlFeNiCoCr as the binder phase and ZrB₂ as the hard phase, ZrB₂-based ceramic composites were prepared by spark plasma sintering (SPS). SEM, EDS and XRD were used to characterize the microstructure and properties of the sintered, corroded, and abraded material samples. The density, fracture toughness, corrosion rate and wear amount of the composite material were measured. The results show that ZrB₂-AlFeNiCoCr ceramics have compact structure and excellent mechanical properties, and the density, hardness and fracture toughness of ZrB₂-AlFeNiCoCr increase with the increase in sintering temperature. However, when the composite material is at 1600 °C, the relative density of the sintering at 1600 °C decreases due to the overflow of the bonding phase. Therefore, when the sintering temperature is 1500 °C, the high entropy alloy has the best performance. The average corrosion rate of ZrB₂-1500 at 700 °C liquid aluminum is 1.225 × 10⁻³ mm/h, and the wear amount in the friction and wear test is 0.104 mm³.