Effect of pre-compressive strain on microstructure and mechanical properties of Mg–2.7Nd–0.4Zn–0.5Zr alloy

Microstructure and High Temperature Tensile Properties of Mg–10Gd–5Y–0.5Zr Alloy after Thermo-Mechanical Processing

“…It can be seen from Figure 6 that the volume fraction of the β precipitate in the pre-deformed specimen is higher than that in the un-deformed sample. SEM and TEM images in Figure 7 show the precipitates that heterogeneously nucleated on the twin and on the twin boundaries in the pre-deformed T6 treated alloy, which is in good agreement with previous findings [14,15].…”

“…The UTS of the pre-deformed sample at room temperature was almost 9% higher than that of age-treated un-deformed alloy. It has also been reported by other researchers that pre-deformation significantly enhanced the strength of the Mg alloys [13][14][15]. The UTS of the T6 treated pre-deformed alloy decreased first as the test temperature was raised to 150 °C, then increased with further raising of the test temperature to 200 °C, and decreased with further raising of the test temperature beyond 200 °C.…”

“…It is well known that precipitates are the most effective barrier to the dislocation movements and cause enhancement in the strength of the alloy at room and high temperatures. Zhao et al [14] reported that the higher density of the β phase in the pre-deformed sample can be the reason for improvement of the strength of the pre-deformed alloy. Nie et al [12] reported that segregation of Gd atoms into twin boundaries in Mg solid solution minimizes the elastic strains associated with individual Gd atoms, which can cause the decrement of the twin boundary energy and reduce the total energy of the system.…”

“…Chen et al [13] studied the effect of annealing on the strengthening of pre-deformed Mg-10Gd-3Y-0.5Zr alloy, and reported that during solution treatment the solute atoms segregated into the deformation twin boundaries and strengthened Mg-10Gd-3Y-0.3Zr alloy; moreover, it was reported that gadolinium solute atoms had a stronger strengthening effect than yttrium atoms. Zhao et al [14] studied the effect of pre-compression plastic deformation between solution and artificial aging treatment on the microstructure, tensile properties and fracture behavior of the Mg-2.7Nd-0.4Zn-0.5Zr alloy. It was reported that, compared to un-deformed samples, the pre-deformed samples offered a higher volume fraction of precipitates after the aging treatment and had higher strength compared to the un-deformed samples.…”

Study on aging strengthening and nano precipitates of Cu–Ni–Mn–Fe alloy

“…Furthermore, the water quenched Cu-Ni-Mn-Fe alloy is rich in vacancies, which supply the heterogeneous nucleation sites for aging precipitates, and the clustering of solute atoms occurs around vacancies during the early stage of decomposition. Due to the interaction between solute atoms and vacancies, accompanied by thermal diffusion, nucleation and growth of solute atoms occur in the segregation region, and thus can accelerate the precipitation [28,29]. Obviously, with the prolongation of aging time, the migration speed and activity of solute atoms will be accelerated, resulting in the increases of the number of precipitates inside the grains.…”