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In this paper, the dynamic recrystallization (DRX) mechanism, texture evolution and the effect of γ ′on the microstructure evolution of a new nickel-based superalloy at 1075 °C and strain rate of 0.01 s−1 were systematically investigated. The results showed that the DRX mechanism undergoes significant alterations with the increase of strain. When the strain is 0.07, the discontinuous dynamic recrystallization (DDRX) constitutes the dominant mechanism. As the strain increases to 0.13, the DDRX mechanism transforms into continuous dynamic recrystallization (CDRX), and the dynamic recrystallization (DRXed) grains grow when the strain is further increased to 0.20. The texture evolution indicated that with the increase of strain, the crystal orientation shifts from and to and , and texture intensity initially weakens and then strengthens, which is closely associated with the DRX mechanism. At a strain of 0.07, the texture is primarily influenced by the DRXed grains. As the strain increases to 0.13, the deformed grains become the dominant factor in determining the texture, and at a strain of 0.20, both the DRXed and deformed grains jointly dominate the texture. The CDRX mechanism facilitates the formation of and textures, while DDRX is mainly related to orientation. Additionally, due to the L12 ordered structure of the γ′ phase, dislocations and stacking faults gradually accumulate in the γ′ phase with the increase of strain, while the dislocation density in the γ matrix initially ascends and then descends.

Hot compression tests are carried out at temperatures ranging from 900 °C to 1050 °C, strain rates ranging from 0.001s−1 to 1s−1 and deformation degree ranging from 60% to 70% on the Gleeble-3500 thermal simulator. Strain-compensated Arrhenius constitutive model, activation energy maps, hot processing maps and microstructure evolution are used to analyse the flow behavior of as-cast Ti-55511 alloy. At low temperature (≤950 °C), the flow softening behavior is mainly related to cracks, deformation bands (DBs) and DRV at high temperature (≥1000 °C) and high strain rate (≥0.1s−1), and DRV at high temperature (≥1000 °C) and low strain rate (≤0.01s−1). DBs and cracks are the main forms of hot deformation instability. There is a competitive relationship between DRV and DBs. Under high strain rate (≥0.1s−1), DBs are more likely to occur. Under low strain rate (

This paper describes our study on the effect of the long-period stacking order (LPSO) phase on the comprehensive mechanical properties of the as-cast Mg-1Al-12Y (wt. %) alloy. The microstructure and tensile mechanical properties of as-cast alloy and solution treatment alloy were evaluated. The results showed that α-Mg matrix, Al2Y phase and β-Mg24Y5 phase were present in the as-cast alloy. After solution treatment, the β-Mg24Y5 phase in the alloy was dissolved and the LPSO phase was precipitated. The solution treatment did not cause grain growth or Al2Y phase change, but the comprehensive mechanical properties of the alloy were significantly improved. This was mainly due to the precipitation of the LPSO phase in the solid solution alloy. In addition, the dissolution of the β-Mg24Y5 phase after solution treatment could also improve the mechanical properties. The improvement of the comprehensive mechanical properties of solution treatment alloys at room temperature was due to the dispersion strengthening caused by the intragranular LPSO phase dispersed within the alloy, which had a good blocking effect on the movement of dislocations. The ductility of the solid-solution alloy was greatly improved at a high temperature while maintaining high strength because the LPSO phase is kinked, the dislocation density was reduced, and more non-basal slip was activated during the high-temperature tension.