Aiming at the bottleneck problems of long process flow and high cost of traditional magnesium alloy sheet preparation, commercial Mg-1.5Mn-0.3Ce alloy sheet was prepared by extrusion and subsequent single-pass rolling process, and its microstructure and mechanical properties were systematically studied. The results show that the strength of the extruded Mg-1.5Mn-0.3Ce alloy rolled at 250 ℃ increases with the increase of single-pass deformation amount. With 48% deformation amount, the alloy has the highest strength in the transverse direction. The yield strength and tensile strength reach 242.9 MPa and 270.0 MPa, respectively, and the elongation after fracture is ~11.8%. After rolling with 48% deformation amount, the grain size is refined from 6.2 to 2.6 μm. A large number of nano-sized α-Mn and Mg₁₂Ce particles are dispersed in the sheet, and high-density residual dislocations are accumulated around the nano-sized second phase particles, which improve the strength of the rolled alloy. Therefore, this work can provide a favorable reference and basis for the the preparation process optimization of low-cost and high-performance magnesium alloy sheets.

Rare-earth elements, as modifiers, exhibit high effectiveness in microalloying, inclusion modification, microstructural optimization, and grain refinement. To improve the comprehensive mechanical properties and service performance of heavy rail steel for complex railway operating conditions, U71Mn heavy rail steels with different La-Ce mixed rare-earth contents were melted in a vacuum induction furnace. The evolution of inclusions was characterized and analyzed using FactSage, SEM, and automatic inclusion analysis software. Vickers microhardness, impact resistance at room and low temperatures, and tensile properties were also tested, together with fracture morphology analysis. The results showed that rare-earth addition transformed the inclusion system from MnS- and silicate-dominated inclusions to (La, Ce)₂O₂S-dominated inclusions. Owing to spheroidization modification, the inclusion morphology evolved from irregular shapes to spherical or ellipsoidal forms. The number of inclusions within the scanned field progressively decreased, with the increasing of rare-earth content. As the total mixed rare-earth content increased from 0 to 0.026%, the microhardness increased from 278 to 287 and 294 HV₃, the yield strength increased from 538 to 582 and 610 MPa, the tensile strength increased from 907 to 948 and 978 MPa, and the elongation after fracture increased from 8.00% to 11.73% and 19.13%. The impact energies at room temperature, -20 and -40 ℃ reached maximum values of 7.6, 7.4, and 6.8 J, respectively, with maximum increases of 52.00%, 54.17% and 112.5% compared with the steel without rare-earth addition. The coefficient of variation of microhardness first increased and then decreased, reaching a minimum of approximately 4.80% at a total rare-earth content of 0.026%, indicating improved homogeneity of the microstructure and mechanical properties.

The third-generation semiconductor material processing equipment technology plays an important role in ensuring material performance advantages, promoting technological innovation and development, and enhancing the overall competitiveness of the third-generation semiconductor industry. Based on the Incopat database and using analysis tools such as Citespace and Excel, combined with literature research and expert consultation, this study conducted a sequential analysis of patent application trends and technology life cycle, technology source regions and market distribution, R&D institution competition situation, and hot research topic technology progress in the field of global third-generation semiconductor material processing equipment technology. Research has shown that the third-generation semiconductor material processing equipment technology has transitioned from the growth stage to the mature stage, but there is still room for innovation in sub fields such as ultrawide bandgap material processing and high-precision surface treatment. Japan and the United States are the main source regions of technology, while China has grown rapidly in the number of patent applications but lags behind in its international layout. The research hotspots focus on high-precision substrate surface treatment and planarization, precise control and uniformity improvement of epitaxial growth, and integrated and automated processing equipment manufacturing.