Anisotropy in tensile behavior of an extruded Mg-4.50Zn-1.13Ca (wt.%) alloy

The present study investigated anisotropy in tensile behavior of an extruded Mg-4.50Zn-1.13Ca (wt.%) alloy through tensile testing along different tilt angles relative to the extrusion direction. Results showed that the as-extruded Mg-4.50Zn-1.13Ca (wt.%) alloy exhibited anisotropy in tensile behavior due to the formation of basal texture. Basal slip, prismatic slip and tensile twinning were the dominant deformation modes depending on the tensile direction. Prismatic slip was the dominant deformation mode for samples with small tilt angle (θ = 0° and 22.5°). Basal slip was activated when the tilt angle was increased, which also resulted in the decrease of yield strength. Tensile twinning was responsible for the yielding of the samples with high tilt angles (θ = 67.5° and 90°). The ductility was significantly reduced at high tilt angle, which was mainly attributed to the appearance of tensile twinning during tensile deformation.

Effect of Loading Direction on the Tensile Properties and Texture Evolution of AZ31 Magnesium Alloy

Samples were cut from an extruded AZ31 magnesium alloy bar for uniaxial tensile and EBSD characterization tests. The long axis and bar extrusion directions were 0° (T0 sample), 45° (T45 sample), and 90° (T90 sample). The effects of loading direction on the tensile behavior, microstructure, and texture evolution of the magnesium alloy were studied. Results show that the obvious mechanical anisotropy of tensile behavior is affected by the loading direction, and the T0 sample with a grain c-axis perpendicular to the extrusion direction has a strong basal texture and high flow stress and yield strength. The loading direction has a significant influence on the microstructure characteristics of different samples, especially the number of {10–12} tensile twins and {10–11} compression twins. Texture evolution results show that the loading direction and the effect of deformation mode on the deformation mechanism lead to variations in texture evolution: the basal slip and prismatic slip during the plastic deformation of the T0 specimen, the compression twin of the T45 specimen, and the tensile twin of the T90 specimen.

Релаксация напряжений несоответствия в гетероструктурах alpha-Ga-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-/alpha-Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- при образовании дислокаций несоответствия

We propose the analytical models describing misfit stress relaxation in α-Ga2O3/α-Al2O3 film/substrate heterostructures taking into account the crystal lattices anisotropy of the heterostructure materials. We consider the nucleation of misfit dislocations as a result of basal or prismatic slip in α-Ga2O3/α-Al2O3 heterostructures with various film orientations. We calculate and analyze the dependences of the critical thickness hc (film thickness above which the nucleation of misfit dislocations is favorable) on the angle ϑ between the polar c-axis and the normal to the film growth plane for α-Ga2O3/α-Al2O3 heterostructures. We demonstrate that accounting for elastic constant C14 is not critical in the considered relaxation models for the α Ga2O3/α Al2O3 heterostructures.

Dynamic Tension Deformation of Rare-Earth Containing Mg-1.9Mn-0.3Ce Alloy Sheet along the Rolling Direction at Various Temperatures

The tensile properties of rare-earth containing Mg-1.9Mn-0.3Ce alloy sheet along the rolling direction were experimentally investigated within the strain rate and temperature ranges of 0.001–1300 s−1 and 213–488 K. The obtained stress-strain responses of the alloy sheet indicate that both yield strength and strain-hardening rate increase when the strain rate increases, whereas they decrease with increase of temperature. Microscopic examination results show that basal slip, prismatic slip, and {101¯2} tension twinning take place in the tensile plastic deformation, while the occurrence of twinning is not obviously affected by the rate and temperature. Tensile samples tend to fracture in a ductile mode with increasing strain rate and temperature.