Effect of cooling rate on the microstructure evolution and mechanical properties of homogenized Mg–Gd–Y–Zn–Zr alloy

Evolution of long-period stacking ordered structure and hardness of Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr alloy during processing by high pressure torsion

“…Previous studies revealed that the mechanical properties could be regulated by controlling the morphology and distributions of LPSO phase [9,10]. Because the Youngʹs modulus of the LPSO phase is higher than the α-Mg matrix and the (0001) basal slip dominates its plastic behaviour, the intragranular lamellarshaped LPSO structures are usually considered to acts as fiber reinforcement to strengthen the alloy, and accommodate the local strain by kink deformation to improve the ductility [11][12][13]. The block-shaped LPSO structures located at GBs can also hinder the slide of dislocations, contributing to the strengthening of the alloy, but the microcracks are prone to initiate at the LPSO-Mg interface due to the generated strain localization and stress concentration [11,14,15].…”

“…Because the Youngʹs modulus of the LPSO phase is higher than the α-Mg matrix and the (0001) basal slip dominates its plastic behaviour, the intragranular lamellarshaped LPSO structures are usually considered to acts as fiber reinforcement to strengthen the alloy, and accommodate the local strain by kink deformation to improve the ductility [11][12][13]. The block-shaped LPSO structures located at GBs can also hinder the slide of dislocations, contributing to the strengthening of the alloy, but the microcracks are prone to initiate at the LPSO-Mg interface due to the generated strain localization and stress concentration [11,14,15]. As-cast LPSO-containing Mg alloys often exhibit low tensile strength because of a coarse grain structure, eutectic phases at grain boundaries and inhomogeneous distribution of coarse LPSO phase [16,17], and cracks may nucleate and propagate along the interface between the massive LPSO and α-Mg matrix close to the grain boundaries due to low bond strength of the interface and poor deformation compatibility [11].…”

“…The block-shaped LPSO structures located at GBs can also hinder the slide of dislocations, contributing to the strengthening of the alloy, but the microcracks are prone to initiate at the LPSO-Mg interface due to the generated strain localization and stress concentration [11,14,15]. As-cast LPSO-containing Mg alloys often exhibit low tensile strength because of a coarse grain structure, eutectic phases at grain boundaries and inhomogeneous distribution of coarse LPSO phase [16,17], and cracks may nucleate and propagate along the interface between the massive LPSO and α-Mg matrix close to the grain boundaries due to low bond strength of the interface and poor deformation compatibility [11].…”

Microstructures, mechanical properties and corrosion behaviors of Mg–Y–Zn–Zr alloys with specific Y/Zn mole ratios

“…1b. What is more, some additional fine lamella are formed inside the a-Mg grains, which has been widely reported in Mg-Zn-RE alloy after solid solution or homogenization [31][32][33]. They also occupy a LPSO structure [33].…”

The effect of homogenization on microstructures and mechanical properties of Mg–7Gd–3Y–1Nd–xZn–0.5Zr (x=0.5, 1 and 2wt.%) alloys

“…Zhen et al [17] reported that the 14H-LPSO phase precipitated from the supersaturated α-Mg matrix at 510°C for 12 h. Yamasaki et al [18] found that 14H-LPSO phase could be transformed from Mg 3 Gdtype eutectic compounds or stacking fault. Xu et al [19] revealed that the 14H-LPSO phase was transformed from 18R-LPSO phase. As a result, four mechanisms are responsible for the formation of the 14H-LPSO phase during homogenization: (1) Precipitation from the supersaturated α-Mg matrix.…”