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Based on the thermodynamic calculations, the universal secondary cooling structure, and the specific water rate for round blooms continuous casting in various diameters were investigated with a 2D heat transfer model. Results indicated that extension of the secondary cooling zone along casting direction significantly lowered the surface temperature recovery after the water cooling, though little influence on the recovering rate. The universal secondary cooling structure for the continuous casting of round blooms in diameters from 280 to 350 mm was optimized by appropriately extending the length of secondary cooling zone. The target unbending temperature was 908 °C for steel 16MnNb due to the thermodynamic calculation. To the optimized universal secondary cooling structure, the optimal specific water rates were 0.35 and 0.25 L kg−1 for the continuous casting of round blooms 280 and 350 mm in diameter, respectively. The present study had been applied to real production, resulting in round blooms in good quality, and contributing to the efficiency and flexibility of round blooms continuous casting process. [ABSTRACT FROM AUTHOR]

Here, the microstructure and mechanical properties are investigated for the designed Mg-4Gd-0.5Zr-xZn (x = 0, 0.2, 0.5, 1.0 and 1.5 wt%) alloys with special emphasis on the effect of Zn. The results show that the designed Mg-4Gd-0.5Zr-xZn alloys exhibit the exceptional ductility. Among them, the Mg-4Gd-0.5Zr-1.0Zn and Mg-4Gd-0.5Zr-1.5Zn alloys show the elongation to fracture as high as 35.2% and 32.5%. Furthermore, a good strength-ductility balance is achieved in the alloys, which is basically ascribed to the grain refinement, texture softening and the precipitation of Zn-containing second phases. As Zn content increases from 0 to 1.5 wt%, the grain sizes of the extruded Mg-Gd-Zr-Zn alloys decrease from 6.02 to 3.05 μm, while the maximum texture intensity decreases from 11.13 to 5.24 m.r.d. Moreover, the Zn 2 Zr 3 and Mg 3 Zn 3 Gd 2 precipitates, which exhibit the completely coherent and semi-coherent orientation relationship with Mg matrix, are induced by the addition of Zn. These coherent and semi-coherent precipitates lead to noticeable strengthening effect and are not easy to become the source of crack, contributing to the high ductility in Mg-4Gd-0.5Zr-1.0Zn and Mg-4Gd-0.5Zr-1.5Zn. • The designed Mg-4Gd-0.5Zr-xZn (x = 0, 0.2, 0.5, 1.0 and 1.5 wt%) alloys all exhibit the exceptional ductility. • The Mg-4Gd-0.5Zr-1.0Zn and Mg-4Gd-0.5Zr-1.5Zn alloys exhibit a good strength-ductility balance. • The orientation relationship between the precipitates and Mg matrix was studied. [ABSTRACT FROM AUTHOR]

Abstract: A new method was employed to obtain GaN nanowires (NWs). In this method, SiC films were deposited with radio frequency (r.f.) magnetron sputtering onto silicon substrates and annealed at high temperature, and then Ga2O3 films were deposited on top of the SiC intermediate layers and annealed in NH3 atmosphere. SiC layer was used to reduce thermal and lattice mismatch between GaN and Si, and improve NWs’ quality. After Ga2O3 films reacted with NH3, a great quantity of GaN NWs with the shape of birch trunks and stalactites were found by transmission electron microscopy (TEM). At the same time, a few very even and uniform pillarlike NWs were observed. The electron diffraction patterns (EDP) show that birch trunk-shaped and pillarlike NWs are all single-crystalline structures. These NWs were also analyzed with the assistance of X-ray diffraction (XRD), Fourier transformed infrared spectra (FTIR) and high-resolution transmission electron microscopy (HRTEM) to show their properties. [Copyright &y& Elsevier]

Aluminum and silicon are common alloying elements for tuning the stacking fault energy (SFE) of high Mn steels. Today the theoretical investigations on the Fe-Mn-Al/Si systems using Density Functional Theory (DFT) are very scarce. In the present study, we employ a state-of-the-art longitudinal spin fluctuations (LSFs) model in combination with DFT for describing the magnetic effects in Fe-Mn based alloys at finite temperature. We find that the traditional DFT-floating spin results fail to explain the experimental trends. However, the DFT-LSFs approach properly captures the Al-induced increase and Si-induced decrease of the SFE of the base alloy in line with the room-temperature observations. This finding highlights the importance of LSFs in describing the Al/Si effects on the SFE of Fe-Mn based alloys. We point out that the effects of the non-magnetic Al and Si additions on the SFE are in fact determined by the magnetic state of the host matrix. In addition, we estimate the role of carbon addition in the alloying effects of Al and Si. The present results provide a convenient pathway to access the important mechanical parameters for designing advanced high-strength alloys. Unlabelled Image • Traditional floating spin models fail to account for the experimental trends. • Longitudinal spin fluctuations yield stacking fault energies in good agreement with experiments. • The magnetic state of the host Fe-Mn alloy is determinative for the alloying trends on the stacking fault energy. [ABSTRACT FROM AUTHOR]

A new type of broadband class‐F power amplifier is proposed with GaN HEMT device CGH40010F. And a new harmonic control network is designed by improving the traditional harmonic control network, with the second harmonic and third harmonic broadband matched, which effectively solves the problem of class‐F power amplifier in the design of the bandwidth. To improve the efficiency of power amplifier, all high‐order harmonics are controlled in a certain bandwidth. CGH40010F power transistor is utilized to build the power amplifier working from 1.5 to 2.6 GHz, with the measured saturated output power >10 W, drain efficiency 60%‐80%, and gain >10 dB. The second and the third harmonic suppression levels are maintained from −19.13 to −47.44 dBc and from −16.18 to −47.9 dBc, respectively. The simulation and measurement results of the proposed power amplifier show good consistency. [ABSTRACT FROM AUTHOR]

The Mg-Al-RE series heat-resistant magnesium alloys are applied in automotive engine and transmission system components due to their high-temperature performance. However, after serving at a high temperature for a long time, the Al11RE3 phase coarsened and even decomposed, while the Mg17Al12 phase grew and dissolved, which limits the service temperature of Mg-Al-RE series heat-resistant magnesium alloys to a maximum of 175 °C. In this study, a new preparation method for in situ AlN particles was presented. The AlN/Mg-4Al-4La-0.3Mn composites were prepared by a master alloy and casting method. The effects of various contents of AlN (0.5–3.0 wt.%) on the microstructure and mechanical properties of the Mg-4Al-4La-0.3Mn (AE44) alloy at room (25 °C) and high temperatures (150–250 °C) were investigated. Microstructure analysis revealed that the inclusion of AlN led to a reduction in both the grain size and second phase size in the AE44 alloy, while also improving the distribution of the second phase. The average grain size, Al11La3 phase, Al2La phase, and Al3La phase of the 2.0 wt.% AlN/AE44 composite were 135.7, 9.6, 1.9, and 12.6 μm, respectively, which were significantly lower than those of the AE44 matrix alloy (179.8, 12.6, 3.3, 17.8 μm). The refinement was attributed to the ability of AlN particles to serve as heterogeneous nucleation cores for α-Mg and, at the same time, impede the growth of the solid–liquid interface, eventually leading to grain refinement. With the increase in the AlN content, the mechanical properties of composites initially exhibited an increase at both room and high temperatures, followed by a subsequent decrease. When the AlN content was 2.0 wt.%, the composite exhibited optimal strength and plasticity matching. At room temperature, the TYS, UTS, and EL values of the 2.0 wt.% Mg-4Al-4La-0.3Mn composite were 96 MPa, 175 MPa, and 7.0%, respectively, which were increased by 26 MPa, 27 MPa, and 0.7% when compared with the base alloy. The TYS of the 2.0 wt.% Mg-4Al-4La-0.3Mn composite at 150 °C, 200 °C, and 250 °C were 17 MPa, 14 MPa, and 22 MPa higher than those of the matrix alloy, respectively. The main strengthening mechanisms were second phase strengthening, load transfer strengthening, and thermal mismatch strengthening. At elevated temperatures, AlN particles effectively pinned the grain boundaries, inhibiting their migration, and hindered dislocation climbing, resulting in excellent mechanical properties of the composites at high temperatures. This study contributes to the advancement of in situ AlN particle preparation methods and the exploration of effects of AlN on the properties and microstructure of Mg-Al-RE alloys at high temperatures (150–250 °C). [ABSTRACT FROM AUTHOR]

This work aims to provide a fundamental study of inclusion characteristics in the single bcc-phase high entropy alloy (HEA), Mn-rich and Al-contained multicomponent system (Al-Cr-Mn-Fe-Co-Ni) was selected as the prototype alloy in this study. According to the differential thermal analysis (DTA) measurements, the solidus (T S) and liquidus (T L) temperatures of this alloy were in the range of 1225–1228 °C (1226 ± 2 °C) and 1268–1271 °C (1270 ± 2 °C), respectively. Non-metallic inclusions were investigated in a two-dimensional (2D) cross-section method as well as extracted by a three-dimensional (3D) electrolytic extraction method. It was found that AlN was the dominant inclusion phase, also a small amount of Al 2 O 3 inclusions were observed. They formed in the liquid alloy and mostly presented as Al 2 O 3 -AlN agglomerates, where the size range of the AlN inclusions was larger than that of Al 2 O 3. The theoretical calculation showed that AlN inclusion has a higher coagulation coefficient and collision rate than those of Al 2 O 3 inclusions, which agrees well with the experimental observations. The inclusion characteristics of Al 2 O 3 and AlN were closely related to the relative contents of O and N in the presence of high Al content in the alloy. The impurity elements of N and O were the key issues in controling the stable inclusion phase in high entropic alloy. • It is the first time to characterize the non-metallic inclusion features in single bcc phase Mn-based high entropy alloy. • It is the first time to provide the thermodynamic consideration of competition of Al 2 O 3 and AlN formation and apply coagulation coefficient in single bcc high entropy alloy. [ABSTRACT FROM AUTHOR]

We have conducted an in-depth study of the magnetic phase due to a spinodal decomposition of the BCC phase of a CrFe-rich composition. This magnetic phase is present after casting (arc melting) or water quenching after annealing at 1250 ºC for 24 h but is entirely absent after annealing in the interval 900–1100 ºC for 24 h. Its formation is favored in the temperature interval ca 450–550 ºC and loses magnetization above 640 ºC. This ferromagnetic-paramagnetic transition is due to a structural transformation from ferromagnetic BCC into paramagnetic σ and FCC phases. The conclusion from measurements at different heating rates is that both the transformation leading to the increase of the magnetization due to the spinodal decomposition of the parent phase and the vanishing magnetization at 640 ºC are diffusion controlled. • AlCrFeCoNi HEA was prepared by arc melting and annealed at 900–1250 ºC for 24 h. • The annealed samples undergoe a spinodal decomposition of a BCC phase into FeCo-and Cr-rich phases and become magnetic. • As-prepared and 1250 ºC annealed materials have a significant fraction of a magnetic phase with a Tc above • All samples become paramagnetic at 640 ºC due to a structural transition into paramagnetic σ and FCC phases. [ABSTRACT FROM AUTHOR]

The micro addition of Ca is demonstrated to noticeably increase the strength and ductility of Mg–Zn–Ce alloy, which is closely correlated with the enhanced alloying segregation at grain boundary. Addition of Ca is found to yield the enhanced Zn segregation and co-segregation of Zn, Ce, and Ca. The mechanism behind is that Ca decreases the segregation energy while promoting the diffusion process of Zn, ultimately accelerating the thermodynamic and kinetic process of segregation. The enhanced alloying segregation induced by Ca effectively stabilizes grain boundary, which contributes to the refined grain size, retardant mobility of dislocation and ultimately improved strength. Furthermore, the intergranular fracture energy can be noticeably increased by Ca owing to the promoted alloying element segregation at grain boundary, which contributes to the improved grain boundary cohesion and ductility. The controllable segregation at grain boundary via alloying is intended to contribute to the development of advanced magnesium alloys. • The micro Ca addition noticeably increases the strength and ductility of Mg–Zn–Ce alloy. • Ca decreases the segregation energy while increasing the diffusion rate of Zn, yielding the enhanced alloying element segregation. • The enhanced alloying segregation stabilizes grain boundary and increases the intergranular fracture energy. [ABSTRACT FROM AUTHOR]

In this study, the nano-micron TiB 2 -Al 2 Y/Mg-9Y-0.6La composites were prepared by introducing nano-TiB 2 and micron-Al 2 Y particles into Mg-9Y-0.6La alloys via the addition of nano-TiB 2 /Al master alloy. The introduction of nano-micron TiB 2 -Al 2 Y particles refined the α-Mg grains, weakened the basal texture, and promoted the dynamic recrystallization of the composites. The yield strength and tensile strength of the 4.31 wt% TiB 2 -Al 2 Y/Mg-9Y-0.6La composite were increased by 69 MPa and 65 MPa, respectively, compared with the Mg-9Y-0.6La alloy. The main strengthening mechanisms of the composites were fine grain strengthening, Orowan strengthening, and coefficient of thermal expansion strengthening caused by the TiB 2 -Al 2 Y particles. [ABSTRACT FROM AUTHOR]

[Display omitted] • This work utilized MOCVD epitaxy to fabricate high quality sp2-bonded BN release layer. • The different nucleation mechanisms of GaN and AlN on the BN surface were investigated. • The quality of GaN epitaxial layer was optimized by adjusting the growth temperature of AlN nucleation layer. • A complete AlGaN/GaN heterojunction structure grown on the highest quality GaN exhibited excellent electrical properties. • The AlGaN/GaN heterojunction was easily transferred, which proved the good 2D characteristics of BN layer. Two dimensional materials, such as sp2-bonded boron nitride (BN) and graphene, have been proven to be excellent templates for the growth and fabrication of independent group III-nitride materials. Herein, wafer level sp2-bonded BN film was successfully grown as a release layer on two-inch sapphire substrate using MOCVD. The different nucleation mechanisms of gallium nitride (GaN) and aluminum nitride (AlN) grown on the BN surface were investigated. We discovered that AlN has a higher nucleation island density compared to GaN on the surface of BN which facilitates better merging of the GaN epitaxial layer. In addition, the quality of the GaN epitaxial layer was optimized by adjusting the growth temperature of AlN. A complete AlGaN/GaN heterojunction structure was subsequently grown on the best quality of GaN, and its average mobility and interlayer carrier concentration was about 1600 cm2 V−1 s−1 and 1 × 1013 cm−2. Finally, the AlGaN/GaN heterojunction was easily transferred from the substrate using tape, which proved the good 2D characteristics of sp2-bonded BN and can undergo non-destructive van der Waals transfer for the upper layer device. [ABSTRACT FROM AUTHOR]

Lithium sulfide (Li 2 S) cathode can pair with metallic-Li-free high-capacity anodes to avoid the notorious lithium dendrite growth and resulting serious safety hazards. However, its high sensitivity to moisture and oxygen makes time-consuming slurry-casting process not appropriate for Li 2 S cathode production. Herein, interconnected carbon nanofibers (CNFs) and porous carbon (PC) inlaid with Li 2 S (Li 2 S@PC@CNF) has been fabricated via a carbothermal reduction strategy by selecting a cost-effective and environmentally friendly precursor, i.e., bacterial cellulose (BC) hydrogel filled with glucose and Li 2 SO 4. Self-supporting Li 2 S@PC@CNF could be directly applied as the cathode, thereby detouring the routinely needed slurry-casting procedure. CNFs serve as a network for electron transport and meanwhile a skeleton to support the free-standing Li 2 S@PC@CNF electrode, while PC seamlessly connects CNFs due to the initial hydrogen bonding between glucose and cellulose, providing physical confinement for lithium polysulfides and large interface area for electrochemical reaction. Thereby, due to its unique ferroconcrete-like architecture, Li 2 S@PC@CNF based LSBs delivers a high initial specific capacity of 700 mA h g−1 with 500 mA h g−1 retained after 400 cycles, and presents promising rate capability of 450 mA h g−1 at 2 C. Image 1 • A facile and economical method to fabricate self-supporting Li 2 S cathodes was demonstrated. • The mechanism for the formation of the self-supporting Li 2 S cathodes has been elucidated. • The Li 2 S cathodes presented excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

It is a great challenge to achieve adsorption and desorption of H 2 on magnesium-based metal materials under room temperature and ambient pressure. To address this problem, we proposed a strategy to tailing the secondary phases in Mg alloy to directly drive catalytic reactions, and utilizing ambient sunlight-driven solar energy to convert heat energy to promote the adsorption and reaction of H 2 and CO 2 gas. Thus, the magnesium-based materials can convert CO 2 into CO and CH 4 under sunlight. Here we report a magnesium-based material LiAlSiO 4 /Mg, where MgO/Mg interface and Li 4 SiO 4 particles play different roles in production CO or CH 4 under varied solar energy. The large amount of MgO reduced the adsorption of H 2 on Mg, while the existence of Li 4 SiO 4 enhanced the production rate of CO. This work explores the functional applications of main-group alloys and paves the way towards ambient sunlight-driven adsorption and use of hydrogen. [Display omitted] [ABSTRACT FROM AUTHOR]

A novel Mg-8Gd-2Y-1.5Zn-1Mn (GYZ-1Mn, wt.%) alloy with extraordinary high-temperature mechanical properties was developed by introducing RE/Zn segregation on α-Mn nanoparticles. Its ultimate tensile stress (UTS) and yield stress (YS) are 312 MPa and 248 MPa at 300 ℃, which are 87 MPa and 52 MPa higher than the highest strengths of other Mg-Gd-Y-Zn alloys reported in the previous literature. The outstanding performance of GYZ-1Mn alloy was associated with the segregation of RE/Zn atoms on the α-Mn nanoparticles, which facilitated the formation of fine lamellar long period stacking ordered (LPSO) phase and impeded the coarsening of α-Mn. Consequently, retarded dynamic recrystallization behavior occurred in the GYZ-1Mn, resulting in fine grain size, high density of geometrically necessary dislocations and strong fiber texture intensity to strengthen the high-temperature mechanical properties. Hence, this work paved a novel path for the development of heat-resistant Mg alloys by introducing elemental segregation on nanoparticles. [Display omitted] [ABSTRACT FROM AUTHOR]

We proposed the localized magnetic moments (LMMs) variation-induced strengthening for Mg alloys. Due to the strong interplay of magnetic and elastic, the introduction of merely 7 wt.% Mn 3 Ga 0.7 Ge 0.3 N in WE43 Mg alloy could not only reduce the coefficient of thermal expansion (CTE) but also enable an enhancement of ∼70% on compressive yield strength and less decrease of ∼2.1% on the elongation. We observed localized uniform lattice deformations and magnetic phase transitions for stress response and verified that the strain involves LMMs variation in the frustrated antiperovskite system, realizing simultaneously reinforcing and toughening in the compressive deformation process. Meanwhile, these magnetic transitions are accompanied by volume shrinkage and thus reduce the CTE of the WE43 Mg alloy. These results demonstrate that the introduction of the secondary phase with the variation of LMMs for stress response is an effective design strategy for alloys to achieve tunable thermal expansion behavior combined with high strength and moderate compressive deformability. [Display omitted] [ABSTRACT FROM AUTHOR]

The mechanical properties of as-extruded Mg-11Gd-5Y-2Zn-0.7Zr (GWZ1152) alloy were systematically studied with respect to their microstructures at room and high temperatures. It exhibited excellent ultimate tensile strength (UTS) of 365 MPa at room temperature (RT), while it maintained relatively high UTS as the temperatures increased to 250 °C (342 MPa), 300 °C (337 MPa) and 350 °C (278 MPa) with a strain rate of 1.85 × 10−3 s−1. The microstructural characterizations revealed that such outstanding heat resistance is mainly attributed to (i) the fine dynamic recrystallized (DRXed) grains and strongly textured un-DRXed grains, (ii) the block-shaped LPSO phase and the nano-scale β precipitates, (iii) the nano-spaced basal LPSO/SFs. Compared to other heat-resistant Mg alloys, our intrinsic chemistry properties contribute to the superior high-temperature mechanical properties of GWZ1152 alloy. For the deformation modes at RT, the dislocations were mainly generated and accumulated on the block-shaped LPSO, followed by cracking and propagation. At 250 °C and 300 °C, non-basal slip inside the coarse un-DRXed was generated, the cracks and fractures were initiated along the slip trace. The main deformation mechanism of GWZ1152 alloy at 350 °C was grain boundary sliding, cracks usually occurred at grain boundaries. • Mg-11Gd-5Y-2Zn-0.7Zr alloy exhibited excellent ultimate tensile strength at 25 °C, 250 °C, 300 °C and 350 °C. • The deformation modes of the alloys were systematically studied at different temperatures. • The relationship between the deformation modes and mechanical properties were discussed at room and high temperatures. [ABSTRACT FROM AUTHOR]

In this study, a novel alloy designing concept, refining grain size and depressing intergranular deformation (inter-GD) simultaneously, is put forward to prepare the Mg alloy with preeminent strength-ductility synergy. A basic alloy, Mg–1Sb–1Mn (SM11), is extruded at 220 °C to attain ultrafine microstructure. Thereafter, the co-addition of Sn and Zn is conducted to inhibit the inter-GD which is the softening mechanism of the ultrafine-grained SM11 alloy. Compared with SM11 alloy, the tensile yield strength, ultimate tensile strength and compressive yield strength of Mg–1Sb–1Mn–1Sn-0.2Zn (SMTZ1110) alloy increases from 196 MPa, 245 MPa and 193 MPa–301 MPa, 361 MPa and 273 MPa MPa respectively, without the loss of tensile elongation. With the co-addition of Sn and Zn, the grain size is refined from 1.07 μm to 0.82 μm. The narrower network spacing of Mg 3 Sb 2 in the as-cast SMTZ1110 alloy promotes particle-stimulation nucleation during extrusion, resulting in finer grains of the extruded SMTZ1110 alloy. The in-situ experiments unveil that the deformation mechanisms in the SM11 alloy are mixed inter-GD and intragranular deformation, while the deformation mechanisms of the SMTZ1110 alloy shift to the modes predominated by intragranular deformation. The transmission electron microscope results show the segregations of Sn and Zn which pin and stabilize grain boundaries and further depress the inter-GD. Under the combining effects of depressing inter-GD and fine-grain strengthening, the strength of the extruded SMTZ1110 alloy is significantly improved. This study provides new insight into the development of Mg alloy with an excellent balance between strength and ductility. [ABSTRACT FROM AUTHOR]

The influence of Y on the microstructure and mechanical properties of Mg-4Gd-0.5Zr alloy is investigated. The results show that by increasing the Y content from 0 to 1.2 wt%, the grain size gradually reduces in both as-cast and as-extruded state, whilst the maximum texture intensity noticeably decreases. In addition, nanoscale particles of Mg 24 (Gd, Y) 5 phase start to precipitate at relatively high Y content. The designed Mg-4Gd-0.5Zr- x Y (x = 0, 0.5, 0.8 and 1.2 wt%) alloys exhibit exceptional ductility and moderate strength. As increasing Y content from 0 to 1.2 wt%, the elongation of Mg-4Gd-0.5Zr-based alloy decreases slightly from 44.6% to 39.0% along the extrusion direction, while the yield strength substantially increases from 87.9 to 134.1 MPa. The main strengthening mechanisms are demonstrated to be solid solution strengthening in combination with the grain refinement. Furthermore, the exceptional ductility maintained in Y-containing alloys is found to closely correlate with the activation of pyramidal slip. • The designed Mg-4Gd-0.5Zr- x Y (x = 0, 0.5, 0.8 and 1.2 wt%) alloys exhibit high ductility and moderate strength. • Massive nanoscale particles of Mg 24 (Gd,Y) 5 phase start to precipitate at relatively high Y content. • The addition of Y in the Mg-4Gd-0.5Zr alloy promotes the activation of pyramidal slip. [ABSTRACT FROM AUTHOR]

The mismatch of thermal expansion in Mg and Al/Cu alloys may cause flaking or destruction at a joint interface, and further restrict their service life and practical application. Combining the negative thermal expansion materials could reduce the thermal expansion of Mg alloys, but destroy their ductility. In this study, we overcome this challenge by the combination of MnCoGe-based alloys with Mg–9Al–1 Zn Mg alloys. The addition of less than 7 wt% Mn 0.98 CoGe has shown matched coefficient of thermal expansion of Cu alloys, and moderated strength and plasticity. Due to the inconsistency with the predicted values, we figured out the critical mechanism on both thermal expansion regulation and mechanical property improvement is attributed to the secondary phases and the metallic bonding interfaces. These Mg alloys with low thermal expansion and good mechanical properties could be useful to the electronic packaging and precision fields. [Display omitted] [ABSTRACT FROM AUTHOR]

Large-scale α-Si3N4 nanotubes were synthesized on Si(1 1 1) by hot-wall chemical-vapor-deposition (CVD) with the assistance of Ga2O3. The cylindrical structures were as long as 30 um with the inside diameters ranging between 20 and 60 nm and the outside diameters ranging between 40 and 100 nm. Scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM) and high-resolution TEM (HRTEM) were used to characterize the size, composition and the structure of the samples. [Copyright &y& Elsevier]

Herein, the microstructure and mechanical properties of newly developed Mg-4Gd-0.5Zr-xNd (x = 0, 0.5, 1 and 1.5 wt%) extruded alloys are investigated systematically. All the extruded alloys exhibit the complete dynamically recrystallized (DRXed) microstructure. The addition of Nd weakens the texture and decreases the intensity of double peak texture apparently from 13.08 to 8.78 m.r.d (at 1.5 wt%). With increasing the Nd content from 0 to 1.5 wt%, the grain sizes of Mg-4Gd-0.5Zr alloys gradually decrease from 11.02 to 7.90 μm, accompanying with massive fine dispersed Mg 41 Nd 5 and Mg 12 (Nd,Gd) particles in the matrix. In terms of mechanical properties, the yield strength increases substantially without the loss of elongation-to-failure basically as increasing the Nd content from 0 to 1.5 wt%. Of those, the Mg-4Gd-0.5Zr-1.5Nd alloy possesses the highest yield strength (160.2 MPa), which is 82.3% higher than that of Mg-4Gd-0.5Zr alloy (87.9 MPa). Meanwhile, the Mg-4Gd-0.5Zr-1.5Nd alloy presents an outstanding ductility (39.3%). • With the increase of Nd content, the YS of VK41 alloy increases substantially without the loss of EL. • The VK41-1.5Nd alloy possesses the highest YS of 160.2 MPa and outstanding EL of 39.3%. • Massive fine dispersed Mg 41 Nd 5 and Mg 12 (Nd,Gd) particles exist in the matrix. [ABSTRACT FROM AUTHOR]

The Invar anomaly is one of the most fascinating phenomena observed in magnetically ordered materials. Invariant thermal expansion and elastic properties have attracted substantial scientific attention and led to important technological solutions. By studying planar faults in the high-temperature magnetically disordered state of [Formula: see text], here we disclose a completely different anomaly. An invariant plastic deformation mechanism is characterized by an unchanged stacking fault energy with temperature within wide concentration and temperature ranges. This anomaly emerges from the competing stability between the face-centered cubic and hexagonal close-packed structures and occurs in other paramagnetic or nonmagnetic systems whenever the structural balance exists. The present findings create a platform for tailoring high-temperature properties of technologically relevant materials toward plastic stability at elevated temperatures., Competing Interests: The authors declare no competing interest.