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The influence of equal channel angular pressing on the tension–compression yield asymmetry of extruded Mg–5.3 Zn–0.6 Ca (weight percent) alloy has been investigated. The microstructure was obviously refined by the large strain during the equal channel angular pressing, accompanied with very fine Ca 2 Mg 6 Zn 3 phases with average diameter of 70 nm. The weak tension–compression yield asymmetry after equal channel angular pressing is mainly attributed to the reduced volume fraction of extension twinning during the compression, because the slope ( k ) of twinning in Hall–Petch relationship is higher than that of dislocation slip, and the twinning deformation is difficult to take place with decreasing grain size. The basal slip is more active in the alloy after equal channel angular pressing, due to the non-basal texture components, which hinders the twinning activation and reduces the yield asymmetry. Furthermore, the presence of fine precipitate restricts the twinning activation, which also contributes to the reduction of yield asymmetry. [ABSTRACT FROM AUTHOR]

Abstract: The microstructure and texture evolution of Mg98.5Y1Zn0.5 and Mg92.5Y5Zn2.5 (atomic percent) alloys during hot extrusion were systematically investigated. The coarse LPSO phases with higher volume fraction (~57%) suppressed the twinning generation in the initial stage of extrusion, and accelerated the dynamic recrystallization through the particle deformation zones. Therefore, the volume fraction of DRXed grains in as-extruded Mg92.5Y5Zn2.5 alloy was much higher than that of Mg98.5Y1Zn0.5 alloy. The intensive recrystallization process resulted in the conventional basal texture weakening, although the texture evolution was mainly dominated by flow behavior. The dynamic recrystallization behavior in Mg92.5Y5Zn2.5 alloy restricted the formation of deformation texture, and thus the more random texture was observed during the whole extrusion process. [Copyright &y& Elsevier]

Abstract: Basing on some growth models of thin film, we have investigated the growth mechanism of glancing angle deposition (GLAD) film. The simulation verifies that the overhangs/vacancies also contribute to the columnar growth as well as the self-shadowing effect for GLAD thin film. Besides, we have studied the effect of the deposition rate, surface and bulk diffusions on the microstructure of thin film using the time-dependent Monte Carlo method. The results show that the surface and bulk diffusions can significantly enhance the packing density of thin film in GLAD growth, and the increase of the deposition rate induce the moderate decrease of the packing density. [Copyright &y& Elsevier]

Tensile yield strength of extruded Mg–5.3Zn–0.5Ca–0.5Ce/La (weight percent) alloy is remarkably increased to 316 MPa from 163 MPa, via the warm rolling process. The tension twinning can be activated after low-strain (5–21%) rolling, and the dynamic recrystallization occurs with increasing rolling reduction. The dislocations are gradually accumulated within the original grains during the rolling, and the number fraction of low angle grain boundary is increased. The coarse secondary phases are gradually broken into small pieces, due to the increased rolling deformation. The weak fiber texture with 10 1 ̅ 0 parallel to extrusion direction in the extruded alloy is modified to the typical 0002 10 1 ̅ 0 texture after rolling, and the yield strength is notably improved, because of the multiple strengthening effects (grain refinement, work hardening, dispersion and texture). A good balance between strength (> 310 MPa) and ductility (~ 9.5%), has been achieved through the warm rolling. [ABSTRACT FROM AUTHOR]

As-cast Mg–5.3Zn–0.6Ca (weight percent) alloy was indirectly extruded at 300 °C with different deformation rates (ram speeds of 0.1, 0.3, 0.5 mms − 1 ), and the microstructure, texture and mechanical properties of the as-extruded alloys were investigated in the current study. With the increase of deformation rates, the average size and volume fraction of dynamic recrystallized grains were remarkably increased. The basal fiber texture became weak in the as-extruded alloy with higher volume fraction of recrystallized grains, because most of the basal planes in these grains were tilted to extrusion direction about 30–40°. The higher deformation rate decreased the tensile yield stress due to the grain coarsening and basal texture weakening, while the elongation was improved, which was resulted from the enhanced work hardening rate. [ABSTRACT FROM AUTHOR]