Sm Alloys Research Articles

Effect of Combined Addition of La and Sm on Mechanical Properties, Microstructure Evolution, and Electrochemical Behavior of Mg-3Zn-1Mn/Sn-0.5Ca Alloy

The effects of the composite addition of La and Sm elements on the microstructural evolution, mechanical properties, and electrochemical behaviors of Mg-3Zn-1Mn/Sn-0.5Ca (wt.%) alloys are systematically investigated. The findings reveal that the Mg-3Zn-1Mn-0.5Ca alloy exhibits excellent ductility, achieving 26% elongation, whereas the Mg-3Zn-1Sn-0.5Ca alloy demonstrates good comprehensive mechanical properties. The addition of La and Sm results in a degree of grain refinement in both alloys and significantly bolsters the strength of the Mg-3Zn-1Mn-0.5Ca alloy, but it has a less pronounced effect on the mechanical properties of the Mg-3Zn-1Sn-0.5Ca alloy. Furthermore, the addition of La-Sm significantly improves the corrosion resistance of both alloys. Electrochemical impedance spectroscopy (EIS) analysis reveals that all four alloys form a double-capacitance loop morphology in 3.5% NaCl, indicating the formation of a protective film during the corrosion process. Among them, the Mg-3Zn-1Mn-0.5Ca-1La-0.5Sm alloy exhibits the largest capacitance loop radius, which is consistent with its polarization curve, indicating the best corrosion resistance. At the corrosion potential of −1.382V, the corrosion current is 8.97 μA·cm−2.

Characterization of Sm-rich phase and properties of hypereutectic Al-Ni alloys modified by Sm

The impact of Samarium (Sm) addition on hypereutectic Al-Ni alloys was systematically investigated, focusing on microstructural changes and thermal-physical, mechanical properties. The addition of 0.1–0.5 wt% Sm resulted in the refinement of primary Al3Ni phases from coarse lath-like structures to small particles, enhancing mechanical properties and reducing thermal expansion coefficients (CTE). Thermal conductivity (TC) improved with 0.1–0.3 wt% Sm addition, but declined at the amount of 0.5 wt%. Excessive Sm addition leads to the formation of a Sm-rich phase, characterized by a two-phase mixed structure of Al11(Ni, Sm)3 surrounded by Al4Sm. Sm addition lowered the precipitation temperature of the primary Al3Ni phase, inducing significant constitutional undercooling and exhibiting a phase refinement effect. The Al-9Ni-0.3Sm alloy showed excellent performance, with a TC of 211.8 W/(m·K), CTE of 17.3×10−6/K (@25–100 °C), ultimate tensile strength of 169.5 MPa, and elongation of 10.4 %. Optimal addition of Sm improved TC, mechanical properties as well as reduced the CTE in the Al alloy at the same time and showed a good modification effect.

Investigations on the interaction of laser parameters for efficient microdrilling of NiTiV smart alloy system

Ni–Ti shape memory alloys (SMAs) are popular in current research due to their usefulness and mechanical properties. At different temperatures, Ni–Ti alloys transition from austenite to martensite. To restore high-temperature memory in nickel-titanium SMAs, vanadium (V) is added as an alloying element. For Ni–Ti-based SMAs, the fiber laser is one of the best machining procedures for bio-implants, actuators, and aircraft engine parts. Using a Box–Behnken design to experiment with laser power, nozzle distance, cutting speed, and frequency, this study examines fiber laser micro-drilled Ni50Ti48V2 SM alloy material removal and hole taper angle. By increasing power (P), frequency (F), and cutting speed (C S ), Ni50Ti48V2 alloy material removal rate (MRR) increased by 75.79%. The hole taper angle (HTA) dropped 75.33% when cutting speed, laser power and frequency decreased. Lowering cutting speed and laser power increases micro-hole circularity and reduces HTA. Upon surface topographical inspection, debris and molten materials were found on the drilled surface. The flow of nitrogen gas caused materials to diffuse on the Ni50Ti48V2 alloy’s entry and exit surfaces, changing surface roughness. High parameters influence surface roughness, HTA, and circularity due to nitrogen gas flow. The material’s DSC and XRD tests confirmed its suitability for biomedical microhole production.

Degraded creep resistance induced by static precipitation strengthening in high-pressure die casting Mg–Al–Sm alloy

Relationship between precipitation strengthening and creep resistance improvement has been an important topic for the widespread applications of magnesium alloys. Generally, static precipitation strengthening through thermal stable precipitates would generate satisfactory creep resistance. However, an opposite example is presented in this work and we propose that the size of precipitates plays a crucial role in controlling the operative creep mechanisms. In addition, the precipitate components along with their crystal structures in the crept Mg–4Al–3Sm–0.4Mn samples with/without pre-aging were thoroughly studied using Cs aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Previous aging generates a large density of fine precipitates (< ∼5 nm) homogeneously distributing in Mg matrix and exhibiting satisfactory strengthening effect. However, the number density of precipitate strings consisting of several or even dozens of relatively coarse precipitates (∼10 nm) was significantly decreased at the same time. As revealed in this work, the relatively coarse particles in Mg matrix are much more efficient than the fine precipitates in promoting dislocation climb. Therefore, the rate-controlling mechanisms are transferred from dislocation climb to dislocation slip after previous aging, thus leading to degradation of creep resistance. Moreover, there are mainly five types of precipitates/clusters, namely β″-(Al, Mg)3Sm, Al5Sm3, ordered Al–Sm cluster, ordered Al–Mn cluster and ordered/unordered AlMnSm clusters. The crystal structures of the former two precipitates were discussed and the formation mechanisms of the precipitates/clusters were revealed.

Ab initio studies of Electronic Structure and magnetic properties of RAl(Mg)3 (R= Ce, Pr, Nd, Sm and Gd) alloys

We report the magnetic behaviour of RAl3 and R(Mg)3 (R= Ce, Pr, Nd, Sm and Gd) alloys studied through ab initio calculations based on density functional theory (DFT). The magnetic moments obtained from the all electron full potential calculations suggest strong magnetic instability in Ce compounds. The compounds with heavier rare earths (Pr, Nd, and Gd) exhibit local moment with high orbital moment, consistent with crystal field splitting of the 4fn ground state. The results obtained for SmAl3 and SmMg3 suggest possible valence fluctuation. Our calculated magnetic moments closely agree with experimental results reported in literature. We have also calculated the magnetic hyperfine field and its spin and orbital contributions. While, the total hyperfine field is dominated by the contribution from orbital magnetic moment, the Fermi contact contribution to the hyperfine field is found to scale with the spin projection factor (gJ−1)J. The calculated hyperfine field values are found to show good agreement with available experimental results.

Simultaneous refinement of α-Mg grains and β-Mg17Al12 in Mg-Al based alloys via heterogeneous nucleation on Al8Mn4Sm

Due to the significant differences in the formation temperature and crystal structure between the primary α-Mg and eutectic β-Mg17Al12, it is a great challenge to achieve simultaneous refinement of the primary and eutectic phases in Mg-Al based alloys via heterogeneous nucleation. Surprisingly, we found that the α-Mg and β-Mg17Al12 in the AZ80 alloy can be simultaneously refined after 0.2 wt.% Sm addition, with the grain size decreasing from ∼217 ± 15 μm to ∼170 ± 10 μm and the β-Mg17Al12 morphology changing from a typical continuous network to a nod-like or spherical structure. The simultaneous refinement mechanism is investigated through solidification simulation, transmission electron microscopy (TEM), and differential thermal analysis (DTA). In the AZ80-0.2Sm alloy, many Al8Mn4Sm particles can be observed near the center of the α-Mg grains or inside the β-Mg17Al12. Crystallographic calculations further reveal that the Al8Mn4Sm has good crystallographic matching with both the α-Mg and β-Mg17Al12, so it possesses the potency to serve as heterogeneous nucleation sites for both phases. The promoted heterogeneous nucleation on the Al8Mn4Sm decreases the undercooling required by the nucleation of the primary and eutectic phases, which enhances the heterogeneous nucleation rate, thus causing the simultaneous refinement of the α-Mg and β-Mg17Al12. The orientation relationships between the Al8Mn4Sm and Mg/Mg17Al12 are identified, which are [1¯21¯0]Mg//[010]Al8Mn4Sm,(101¯0)Mg//(301)Al8Mn4Sm and [1¯12]Mg17Al12//[010]Al8Mn4Sm,(110)Mg17Al12//(301)Al8Mn4Sm, respectively. Furthermore, the refinement of the β-Mg17Al12 accelerates its dissolution during the solution treatment, which is beneficial for cost saving in industrial applications. Other Al8Mn4RE compounds such as Al8Mn4Y might have the same positive effect on the simultaneous refinement due to the similar physicochemical properties of rare earth elements. This work not only proves the possibility of simultaneously refining the primary and eutectic phases in Mg-Al based alloys via heterogeneous nucleation, but also provides new insights into the development of refiners for cast Mg alloys.

Effect of samarium modification on the microstructures evolution and mechanical properties of high strength aluminum alloy

High strength aluminum alloys have been used in various industries, but increasing the strength and ductility of the alloy simultaneously remains a challenge. To solve this problem, a novel Al-Zn-Mg-Cu-Zr( Sm) alloy with Sm addition was prepared. The results show that the Sm element exists in the form of Al 10 Cu 7 Sm 2 phase, with a small amount distributed in the matrix and eutectic phases. After Sm modification, the recrystallization behavior was inhibited, and the substructure and deformation microstructure in the extruded alloy were improved. Moreover, Sm can effectively promote the formation of η’ phase and inhibit the conversion of η’ phase to η phase. Based on the above factors, the strength of the alloy was improved. Meanwhile, for the modified alloy, grain refinement reduces crack nucleation and finely dispersed precipitates reduce stress concentration, which is also responsible for the increased ductility of the alloy. • The effect of different Sm content on the microstructure of Al-Zn-Mg-Cu-Zr alloy was studied. • Sm in Al-Zn-Mg-Cu-Zr alloy mainly exists as Al 10 Cu 7 Sm 2 intermetallic compound, and a small amount is dissolved in the matrix and eutectic phase. • Sm can inhibit the recrystallization behavior of the alloy and promote the precipitation of η’ phase. • When the Sm content is 0.3%, the alloy has higher strength and toughness. • Mechanism of tensile fracture and alloy strength and toughness improvement is discussed.

An insight into a novel Mg2InSm prismatic plate in Mg-In-Sm alloy

• A novel Mg 2 InSm prismatic platelet can form in the aged Mg−In−Sm alloys. • The platelet has an aspect ratio of ∼25 and can keep a coherent relation with matrix. • The platelet is deemed as generalized β ″ with a (Mg 2 In)Sm-type D0 19 structure. Prismatic precipitate platelet is always purposefully designed in the microstructure of magnesium alloys due to its greater contribution to yield stress. In this study, with an introduction of In into Mg-Sm system, a category of novel { 10 1 ¯ 0 } α prismatic platelets has replaced thoroughly the traditional β ′ precipitate formed in magnesium rare earth (Mg-RE) alloys. Herein, the microstructural characteristics of platelet are investigated particularly by atomic scale scanning transmission electron microscopy. It is confirmed that the platelet has a Mg 2 InSm composition and can maintain a coherent relationship with α-Mg matrix. Importantly, on account of the similarities between In and Mg atoms, the Mg 2 InSm prismatic platelet could be structurally categorized as a generalized β ″ precipitate with a (Mg 2 In)Sm-type D0 19 structure when both In and Mg are regarded as an equivalent atom. Thus, the addition of In into Mg-Sm alloy induces the formation of β ″ precipitate. Furthermore, the formed β ″ prismatic platelets generally have a large average aspect ratio. The findings are of great significance to construct the effective precipitation strengthening phases and optimize the microstructure of Mg-based alloys. With an addition of In into Mg-Sm system, a type of novel { 10 1 ¯ 0 } α prismatic platelet has occurred and replaced the traditional β \prime precipitate. The prismatic platelet has a composition of Mg 2 InSm and can be categorized into a generalized β ″ phase with a (Mg 2 In)Sm-type D0 19 structure when Mg and In are deemed as a mixed atom.

Connections between structural characteristics and crystal nucleation of Al–Sm glasses near glass transition temperature

A systematic investigation on connections between structural characteristics and crystal nucleation during isothermal devitrification of Al–Sm glasses has been carried out by utilizing molecular dynamics simulations combined with an effective data-driven approach named principal component analysis. The results suggest that icosahedral order dominants the local orders in Al–Sm liquids and glasses, whereas the development of crystal-like clusters has been greatly suppressed. Doping of Sm not only increases the population of icosahedral order in Al–Sm alloys, but also promotes the tendency of formation of icosahedral medium range order. Based on the calculation of local density and bond-orientational order parameters, a distinct decoupling in spatial distributions of fluctuations in local density and bond-orientational order is observed, and an obvious lagging of densification behind structural ordering is unveiled. These facts unambiguously evidence that the bond-orientational order instead of local density is the determinant factor for the origin of crystal nucleation in Al–Sm glass.

Effect of Precipitates in Mg−Sm Alloys on Their Deformation Behavior and Yield Asymmetry

The strengthening effect of precipitates in a Mg−0.4Sm (wt%) alloy on dislocation slip and extension twinning (ET) is evaluated by experimental work and viscoplastic self‐consistent (VPSC) modeling. Experimental results reveal that the extruded Mg−Sm alloy consists of rare‐earth texture (&lt;−12−11&gt; // ED) and extrusion texture (&lt;−12−10&gt; // ED) components. After aging precipitation, tensile yield stress is more effectively enhanced than compressive yield stress. Transmission electron microscopy (TEM) analysis confirms that the precipitates in the aged Mg−Sm alloy are of β′ with an orthorhombic crystal structure. The introduction of β′ precipitates in the compression sample stimulates a higher fraction of extension twins. VPSC modeling indicates that the critical‐resolved shear stresses (CRSS) for prismatic slip, pyramidal &lt;c + a&gt; slip, and basal slip are increased by 75, 30, and 6 MPa, respectively, by aging precipitation, while the precipitation strengthening on ET is negligible. By preferentially hardening against prismatic slip, the compressive and tensile yield asymmetry are increased for the aged Mg−Sm alloy.

Phase equilibria of Sm-Fe-Ti-M (M = Cu, Ag) systems and wetting behavior of M-Sm alloys on SmFe11Ti substrate

A SmFe12-nXn permanent magnet requires the formation of a suitable grain boundary phase in the microstructure. In this study, Cu and Ag were selected as the major components of the grain boundary phase, and phase equilibria involving the SmFe11Ti phase were investigated. The wettability behavior of the molten grain boundary phase on SmFe11Ti was studied based on this investigation. In the phase equilibria investigation for Fe–Ti–Sm–M (M = Cu, Ag), SmFe11Ti equilibrated Cu-41 mol% Sm and Ag-44 mol% Sm at 1273 K in Cu and Ag systems, respectively. During study of the wetting behavior, molten Cu-41 mol% Sm alloy that equilibrates with SmFe11Ti exhibited good wettability on the SmFe11Ti substrate, with a final contact angle of 8° at 1133 K. The molten Ag-44 mol% Sm alloy that equilibrates with SmFe11Ti also exhibited good wettability, with a final contact angle of less than 1° at 1273 K. Although the damage to the SmFe11Ti substrate by Ag-44 mol% Sm alloy seemed smaller, the difference in the damage to the substrate could not be evaluated between Cu-41 mol% Sm alloy and Ag-44 mol% Sm alloy because the Ag-44 mol% alloy wetted the entire substrate and flowed down through the lateral side of the substrate.

Effect of Ca and RE (Y, Sm) on microstructure and mechanical properties of as-cast AZ91 magnesium alloy

AZ91 magnesium as a lightest structural material, of the alloying additions to magnesium to date, composite Ca, Y and Sm have not been studied. Herein, the effects of Ca and RE(Y, SM) on the microstructure and mechanical properties of as-cast AZ91 magnesium alloy were studied. The results showed that the addition of 1 wt% Ca into AZ91 magnesium alloy could effectively refine the grains, and change the second phase distribution as well. Based on that, the addition of Y and Sm can change the second phase distribution of as-cast AZ91-1Ca alloy. When the content of Y and Sm increased to 0.67 wt% and 0.33 wt% respectively, Al2Y,Al2Sm and Al2(Yx, Sm1-x) composite phases are introduced to refine the alloy grains, also change the size and distribution of the second phase (Mg17Al12,Al2Ca). Furthermore the mechanical properties of AZ91 magnesium Alloy can be improved by Ca and RE (Y, Sm), among which the comprehensive mechanical properties of AZ91-1Ca-0.67Y-0.33Sm alloy has the best presentation, Consequently, the yield strength and tensile strength reached the highest, which are 126 MPa and 198 MPa respectively due to the ensuring elongation. The fracture mode of magnesium alloy can be changed by composite addition of Ca and RE (Y, Sm).

Density and Electrical Resistivity of Al–Ni–Co–Sm(Tb) Alloys

Density and Electrical Resistivity of Al–Ni–Co–Sm(Tb) Alloys

Biocompatibility of Ni–Cr alloys, with the same composition, prepared by two new digital manufacturing techniques

This study evaluated the in vitro biocompatibility of nickel–chromium (Ni–Cr) alloys produced via three different manufacturing techniques (casting, selective laser melting [SLM], and soft milling [SM]) from a single alloy with the same elemental composition. The microstructure, ion release, and cell viability of the alloys were studied. The Ni-based γ phase was identified for the three alloys. A segregation of the Cr and molybdenum (Mo) was observed in the cast alloy. The SLM and SM alloys exhibited a more homogeneous elemental dispersion and a finer grain formation than the cast one. Extensive porosity as well as (Mo,Cr)C carbide were generated in the SM alloy. The SLM alloy showed the lowest release of Ni ion, followed by the SM alloy (p < 0.001) and then the cast alloy (p < 0.05). The SLM alloy also exhibited the greatest density and viability of L929 mouse fibroblasts, followed by the SM alloy (p < 0.05) and lastly the cast alloy (p < 0.001). It was concluded that the SLM alloy had superior biocompatibility, cell viability of the SM alloy being slightly less but still greater than that of cast alloy.

Effect of Sm Doping on the Microstructure, Mechanical Properties and Shape Memory Effect of Cu-13.0Al-4.0Ni Alloy.

The effects of rare earth element Sm on the microstructure, mechanical properties, and shape memory effect of the high temperature shape memory alloy, Cu-13.0Al-4.0Ni-xSm (x = 0, 0.2 and 0.5) (wt.%), are studied in this work. The results show that the Sm addition reduces the grain size of the Cu-13.0Al-4.0Ni alloy from millimeters to hundreds of microns. The microstructure of the Cu-13.0Al-4.0Ni-xSm alloys are composed of 18R and a face-centered cubic Sm-rich phase at room temperature. In addition, because the addition of the Sm element enhances the fine-grain strengthening effect, the mechanical properties and the shape memory effect of the Cu-13.0Al-4.0Ni alloy were greatly improved. When x = 0.5, the compressive fracture stress and the compressive fracture strain increased from 580 MPa, 10.5% to 1021 MPa, 14.8%, respectively. When the pre-strain is 10%, a reversible strain of 6.3% can be obtained for the Cu-13.0Al-4.0Ni-0.2Sm alloy.

Comparison of Biocompatibility of Three Soft Milled Cobalt-Chromium Alloys.

In the context of biology and medicine, nanotechnology encompasses the materials, devices, and systems whose structure and function are relevant for small length scales, from nanometers through microns. The purpose of this study was to compare the microstructures and resultant biocompatibility of three commercially available soft milled cobalt-chromium (Co-Cr) alloys (Ceramill Sintron, CS; Sintermetall, SML; and Soft Metal, SM). Disc-shaped specimens were prepared by milling the soft blanks and subsequent post-sintering. The crystal and microstructures of the three different alloys were studied using optical microscopy, X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy, and electron backscatter diffraction. The amounts of Co, Cr, and molybdenum (Mo) ions released from the alloys were evaluated using inductively coupled plasma-mass spectroscopy. The effect of ion release on the viability of L929 mouse fibroblasts was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The SML alloy showed a finer grain size (approx. 5 μm) and a larger pore size (approx. 5 μm) than the CS and SM alloys, and its XRD pattern exhibited a slightly higher ε phase peak intensity than that of the γ phase. In the CS and SML alloys, the average crystallite sizes of the nano-sized Cr23C6 carbide were 21.6 and 19.3 nm, respectively. The SML alloy showed higher concentrations of Cr and Mo in the grain boundaries than the other two alloys. The SML alloy showed significantly higher Co and Mo ion releases (p < 0.001) and significantly lower cell viability (p < 0.05) than the CS and SM alloys. The combined results of this in vitro study suggest that the three soft milled Co-Cr alloys had different crystal and microstructures and, as a result, different levels of in vitro biocompatibility.

Simulation of Domain Structure in Sm(Co, Fe, Cu, Zr)7.5-Type Alloy After Different Heat Treatments

The domain structure and its change as a result of heat treatment of alloys of type Sm(Co, Cu, Fe, Zr)7.5 is simulated with the use of the FMRM software based on the phenomenological approach to analysis of processes of reversal magnetization. Adequacy of the results of the simulation of the domain structure is checked by comparison with published data on experimental studies of similar alloys and heat treatments. The conditions of formation of domain structure in the alloys and the factors affecting the domain size are determined.

Low temperature magnetic properties of the quasicrystalline Al80Mn12Si4X4 (X = Cr, Y, Sm and Nd) alloys

Quasicrystalline Al80Mn12Si4X4 (X = Cr, Y, Sm and Nd) alloys were produced and their magnetic properties were investigated. X-ray diffraction and scanning electron microscopy revealed the presence of atomic arrangements with pentagonal symmetry. The nature of the coupling of the magnetic moments was investigated for temperatures (T) varying from 2.0 to 300.0 K and for applied magnetic fields in the range ± 85.0 kOe. The dc magnetic susceptibility indicated that the net magnetic interactions are antiferromagnetic for the samples with Cr and Y. However, the samples with Sm and Nd showed to be ferromagnetic at low-T. The coercivity and the remanence determined from hysteresis loops at 5 K for the sample with Sm (Nd) was, respectively, 0.54 kOe (0.40 kOe) and 0.047 emu/g (0.19 emu/g). A spin-glass-like phase was observed for the AlMnSiNd (AlMnSiSm) sample below 2.7 K (2.4 K). The results are accounted for by taking into consideration the coupling among the rare earth magnetic moments.

Phase evolution of a novel Al–Zn–Mg–Cu–Zr–Sm alloy during homogenization annealing treatment

The effects of pretreatment and homogenization on the microstructure of a new Al-6.7Zn-2.6Mg-2.0Cu-0.1Zr-0.3Sm alloy were investigated. The results show that severe dendritic segregation is visible at the grain boundaries of the as-cast microstructure, which consists of the η (Mg (Zn, Cu, Al)2), Al10Cu7Sm2 and Fe-rich phases. Besides, some small η and needle-shaped θ (Al2Cu) phases are distributed inside of the grains. After pretreatment at 400 °C for 10 h, the η phase and θ phase in the grains are dissolved, and Al3Zr particles are precipitated inside of the grains by homogeneous nucleation. However, dendritic segregation still exists at the grain boundaries. After homogenization annealing, the η phase present at the grain boundaries completely dissolves, and only a small number of Al10Cu7Sm2 and Fe-rich phases remain. The alloy microstructure becomes more uniform and the volume fraction of residual eutectic decreases to 0.70% after homogenization annealing. The optimal homogenization processing is determined as 400 °C/10 h + 470 °C/24 h, which is in perfect accordance with the results obtained via homogenizing kinetic analysis.

Influence of Sm addition on microstructural and mechanical properties of as-extruded Mg–9Li–5Al alloy

In this study, the influence of Sm addition on microstructural evolution and mechanical properties of as-extruded Mg–9Li–5Al (LA95) alloy was characterized by OM, SEM, TEM, XRD and EDS. The morphology results showed that adding Sm resulted in the formation of Al2Sm phase, and the grains of the LA95 alloy were markedly refined with the addition of Sm. Additionally, the dislocation pile-up around the Al2Sm particles were observed by high-resolution transmission electron microscopy. The as-extruded LA95-0.4Sm alloy with granular Al2Sm phase showed optimal ultimate tensile strength of 283 MPa, which was about 25% higher than that of the matrix alloy. The main factors influencing the strength of as-extruded LA95-xSm alloys were as follows: (i) grain refinement strengthening, the lattice mismatch calculation results showed that the average lattice mismatch of (111)Al2Sm//(0001)α-Mg was 12.5%, which indicated that the Al2Sm phase served as an effective heterogeneous nucleation substrate of the α-Mg phase to refine the α-Mg phase in LA95 alloys; (ii) second phase strengthening, the fine Al2Sm particles exerted positive effects on strengthening by effectively hindering the dislocation line movement, thereby forming the dislocation pile-up adjacent to the strengthening phase Al2Sm.