Addition Of Sm Research Articles

Influence of Samarium (Sm) Addition on Mechanical and Tribological Performance of the Al–Mg Alloy AA5083

Influence of Samarium (Sm) Addition on Mechanical and Tribological Performance of the Al–Mg Alloy AA5083

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.

Insight into the stabilization mechanism of Zn during co-gasification of sewage sludge and coal: Perspective of solid-liquid transition

In this study, the underlying mechanism of zinc (Zn) stabilization during the co-gasification of sewage sludge (SS) with Shenmu coal (SM) was investigated using an in-situ visual furnace to analyze the distribution of Zn species. The findings classified two distinct stages within the co-gasification process: the organic matter gasification stage, occurring below 1000 °C, and the inorganic mineral melting stage, occurring above 1000 °C. The addition of SM can extend the organic matter gasification phase, in which the porous carbon structure of the SM char aids in the capture of Zn released during the devolatilization of SS. However, a sustained reducing atmosphere promoted the formation of Fe3O4, causing Zn destabilization. Subsequently, during the inorganic mineral melting stage, the complete reaction of carbon released Zn, which was adsorbed onto the carbon surface. Furthermore, the ash from SM contributes to the melting of the co-gasification residues, enhancing Zn stabilization through encapsulation by the molten phase and stabilization within the spinel lattice. This study highlights the critical role of liquid encapsulation in Zn stabilization during co-gasification.

Role of combinative In and Sm additions in tailoring the discharge performance of extruded AZ31 alloys as anodes for seawater batteries

The discharge behaviors of AZ31 alloys, modified by the addition of In and Sm elements in conjunction with equal channel angular pressing (ECAP) processing, were systematically explored. The incorporation of In suppressed the formation of cathodic second phases. In contrast, Sm promoted the precipitation process and therefore led to higher microstructure uniformity following ECAP processing. The solid-solution In contributed to the activated dissolution of Mg matrix and the inhibited hydrogen evolution during discharge, while Sm was beneficial for the uniform dissolution and the alleviation of chunk effect. The results indicated that the 12-pass ECAP processed AZ31-In-Sm anode revealed the most enhanced discharge performance with a discharge voltage of 0.889 V and a utilization of 66.94% at 100 mA cm−2. This improvement can be primarily attributed to the combined effects of the decreased precipitations of cathodic phases by In addition and the enhanced microstructure homogeneity by Sm addition, collaborated with significant microstructure refinement.

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.

Effect of samarium on microstructure and mechanical properties of dilute Mg-Al-Ca alloys

To facilitate the industrial application of wrought Mg alloys, this study explores the impact of the rare earth (RE) element Sm on the microstructure and mechanical properties of hot-rolled Mg-1Al-0.3Ca alloy. The results indicate that the average grain size and basal texture intensity of the hot-rolled Mg-1Al-0.7Sm-0.3Ca alloy are significantly reduced compared to the hot-rolled Mg-1Al-0.3Ca alloy. This reduction can be attributed to the pinning effect of grain boundaries and grain refinement facilitated by the presence of the fine Al2Sm phase. Additionally, the addition of Sm leads to an increase in yield strength and ultimate tensile strength, along with a decrease in elongation. This can be attributed to the combined effects of the strengthening mechanism provided by a significant number of Al2Sm particles and the stress concentration occurring at the sharp corners of these particles. Significantly, this study proposes the substitution of expensive RE elements with more cost-effective Sm in the design of Mg alloys for low-alloy systems. The excellent mechanical properties of the Mg-1Al-0.7Sm-0.3Ca alloy provide a reference for the future development of high-performance Mg alloys.

Rational design of SiBCN ceramics with excellent attenuation to strong electromagnetic-wave-absorbing properties at low frequency

To achieve strong electromagnetic wave absorbing properties, it is important to have good impedance matching, moderate electrical conductivity, and high polarization loss, particularly at low frequency. However, meeting these requirements for polymer-derived ceramics remains challenging. This paper proposes a simple approach to addressing this challenge by adjusting the crystallinity and defects of SiBCN ceramics. The addition of Sm as a catalyst and tailored heating temperatures were used to create SiBCN ceramics with adjustable crystallinities and defective nanograins. The controlled crystallinity provided good impedance matching, while the tailored defective nanograins offered high polarization loss. The combination of these factors results in high-performance electromagnetic wave absorption, with the SiBCN ceramics achieving a minimum reflection loss of −59.13 dB at 3.6 GHz and an effective attenuation bandwidth of 6.87 GHz with a thickness of 2.22 mm. This study provides an effective strategy for the design and fabrication of strong EMW absorbing materials.

Insights into the effects of Sm on microstructure evolution mechanism and mechanical properties of Mg-8Gd-2Y–1Zn-0.5Zr cast alloy at high temperature

In this study, the effects of 1 % Samarium (Sm) on the microstructure and room and high temperature mechanical properties of Mg-8Gd-2Y–1Zn-0.5Zr alloy are discussed and analyzed. The addition of Sm increases the volume fraction of lamellar and blocky long-period stacking ordered (LPSO) phases and promotes the precipitation of lamellar β′ and β phases. The high yield strength and ultimate tensile strength of Mg-8Gd-2Y-1Sm-1Zn-0.5Zr alloy at room and high temperatures are mainly attributed to the strengthening effects of LPSO, β, and β′ phases. The LPSO, β, and β′ phases effectively hinder the movement of dislocations and inhabit the migration of grain boundaries. The Mg-8Gd-2Y-1Sm-1Zn-0.5Zr alloy shows superior yield strength (203.3 MPa) and ultimate tensile strength (258.9 MPa) at 350 °C, which are respectively 67.2 MPa and 23.8 MPa higher than those of Mg-8Gd-2Y–1Zn-0.5Zr alloy (136.1 MPa and 235.1 MPa).

Unraveling the intrinsic mechanism behind the retention of arsenic in the co-gasification of coal and sewage sludge: Focus on the role of Ca and Fe compounds

Minimizing the emission of arsenic (As) is one of the urgent problems during co-gasification of Shenmu coal (SM) and sewage sludge (SS). The intrinsic mechanism of As retention was obtained by analyzing the effect of different SM addition ratios on the As form transformation during co-gasification at 1000 °C under CO2 atmosphere. The results showed that the addition of SM effectively promoted the enrichment of As in the co-gasified residues. Especially, the best As retention rate of 65.71% was achieved with the 70 wt% addition ratio of SM. The addition of SM promoted the adsorption and chemical oxidation of As(III) to the less toxic As(V) through the coupling of Ca and Fe compounds in the co-gasified residues. XRD and XPS results indicated that Fe2O3 adsorbed As2O3(g) after partial conversion to Fe3O4 by the Boudouard reaction, while part of As2O3 was oxidized to As2O5 by lattice oxygen. Finally, the generated As2O5 was successively trapped by CaO and Fe2O3 to form stable Ca3(AsO4)2 and FeAsO4. HRTEM and TEM analysis comprehensively proved that As(III) was stabilized by the lattice cage of CaAl2Si2O8. In conclusion, the co-oxidation of Ca and Fe compounds and lattice stabilization simultaneously played a crucial role in the retention of As2O3(g) during co-gasification.

Revealing the mechanism of Sm element on the long period stacking ordered structures of Mg–Zn-Gd alloy

In the current work, the mechanism of the Sm-modified Mg–Zn-Gd alloy and its effect on the microstructure and mechanical properties of as-cast and as-aged alloy are systematically investigated. Experimental results reveal that adding Sm promotes the formation of long-period stacking ordered (LPSO) phase in as-cast Mg–Zn-Gd alloy. The reason is that the Sm element can reduce the stacking fault energy and introduce a large number of stacking faults (SFs) in the magnesium, which promotes the formation of the LPSO phase. During the heat treatment process, SFs and Mg3RE phases can promote the nucleation of β′ precipitates owing to the Mg3RE phase being coherent with the α-Mg matrix and LPSO phase. The Sm addition not only effectively refines the grain structure of as-cast alloy but also promotes the formation of stacking faults and the LPSO phase. The mechanical properties of Sm-containing alloys in as-cast and as-aged states are superior to Sm-free alloys, ascribed to the relatively refined grains, solid-solution strengthening, and sufficient fine β’ aging precipitates.

Effect of Sm Addition on the Electrochemical Behavior and Discharge Performance of Mg-1Sn-1Ca-0.3Mn Alloy as Mg-Air Battery Anodes

Sm element is a relatively inexpensive rare Earth element. The effect of Sm content on the microstructure, electrochemical behavior and discharge performance of Mg-1Sn-1Ca-0.3Mn (TX11) alloy was investigated through scanning electron microscopy (SEM), electrochemistry workstation and Mg-air battery tests. Results reveal the addition of Sm does not change second-phase morphology of TX11 alloy, CaMgSn and Mg2Ca phases solidly dissolves Sm elements. The electrochemistry results depict that Sm addition deteriorates the corrosion resistance and electrochemical activity of TX11 alloy, which is attributed to Sm solid solution changing the original second phase properties. In addition, Mg-1Sn-1Ca-0.5Sm-0.3Mn anode presents the highest anodic efficiency and specific capacity among Mg-1Sn-1Ca-xSm-0.3Mn (x = 0. 0.5, 1, 2 wt%) alloys, those value is 60.2% and 1306.801 mA h g−1, respectively, which attribute to the highest dissolution activity and the smoother discharge surface morphology. Micro-Sm alloyed is beneficial for improving the anodic efficiency of TX11 anode.

Catalytic hydrolysis of carbonyl sulfide in blast furnace gas over Sm-Ce-Ox@ZrO2 catalyst.

Carbonyl sulfur (COS) is a prominent organic sulfur pollutant commonly found in the by-product gas generated by the steel industry. A series of Sm-doped CeOx@ZrO2 catalysts were prepared for the hydrolysis catalytic removal of COS. The results showed that the addition of Sm resulted in the most significant enhancement of hydrolysis catalytic activity. The 3% Sm2O3-Ce-Ox@ZrO2 catalyst exhibited the highest activity, achieving a hydrolysis catalytic efficiency of 100% and H2S selectivity of 100% within the temperature range of 90-180 °C. The inclusion of Sm had the effect of reducing the acidity of the catalyst while increasing weak basic sites, which facilitated the adsorption and activation of COS molecules at low temperatures. Appropriate doping of Sm proved beneficial in converting active surface chemisorbed oxygen into lattice oxygen, thereby decreasing the oxidation of intermediate products and maintaining the stability of the hydrolysis reaction.

Effect of Samarium (Sm) Addition on Microstructure and Mechanical Properties of AA5083 Alloy

Effect of Samarium (Sm) Addition on Microstructure and Mechanical Properties of AA5083 Alloy

Achieving High Self-Lubricating Performance of Al-Bi-Sm-Ti Alloys Based on the Intermetallic Compounds

Al-Bi immiscible alloys, as wear resistance material, have attracted increasing attention in the past. The solidification processing of alloys plays a significant role in the final solidification microstructure and properties of immiscible alloys. Here, we present a strategy to produce a homogeneous microstructure in Al-Bi alloys based on intermetallic compounds. With the addition of Sm and Ti, the effect on the microstructure and properties was discussed in detail. The Al-Bi-Sm-Ti alloys achieve high self-lubricating performance, referring to the values of the coefficient of friction and wear rate. The intermetallic compounds formed were regarded as the main anti-friction and anti-wear factors. The results of numerical simulation indicate that microsegregation in Al-Bi alloys was retarded based on the intermetallic compounds. The coefficient of friction of the Al-Bi-1Sm-2Ti alloy was 46.2% lower than that of the Al-Bi alloys at 300 m. This research provides a new perspective and guidance for designing and fabricating composites with superior self-lubricating properties.

Samarium addition-mediated simultaneous achievement of excellent resistance drift and superior thermal stability in phase-change compound antimony-selenium thin film

The Sm-doped Sb7Se3 thin films were systematically investigated, including phase change behavior, phase structure, microstructure, and electrical properties. The in-situ resistance test displays that the addition of Sm element leads to a significant increase in the crystallization temperature, decadal data retention and crystallization activation energy, implying better thermal stability. Crystallization kinetic analysis indicates a one-dimensional growth crystallization pattern, exhibiting an ultra-fast crystallization speed. The change in optical bandgap reflects that the exotic Sm atoms enhance the bandgap energy, which facilitates the reduction of the threshold current. Resistance drift test highlights the suppression of structural relaxation by Sm atoms, which would greatly improve the reliability of the information readout. X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectra, and transmission electron microscopy demonstrate that the addition of Sm retards the crystallization process and refines the grain size. Energy dispersive spectroscopy shows that the Sm dopant has incorporated into Sb7Se3 thin film. The phase change memory cell based on Sm-doped Sb7Se3 film exhibits faster running speed (100 ns) and lower power consumption (3.0 × 10−11 J) than the conventional Ge2Sb2Te5 material. All the results prove that incorporating appropriate amounts of Sm into Sb7Se3 material is an ideal technique for optimizing resistance drift and thermal stability of Sb7Se3 thin films.

Effect of Ce, Sm and Sr micro-alloying on the microstructure, mechanical properties and anisotropy of rotated rolled Mg–4.5Al–1.5Sn–0.5Ca–0.2Mn alloy

Mg–Al series sheets usually exhibit an apparent mechanical anisotropy induced by strong basal texture. In this study, a near-isotropic Mg–4.5Al–1.5Sn–0.5Ca–0.2Mn (ATXM5210) alloy was developed via 0.05 wt.% Sr micro-alloying combined with rotated rolling, displaying an ultra-low difference in yield strength (∼5 MPa), ultimate tensile strength (∼2 MPa) and elongation (∼1 %) between the rolling direction (RD) and transverse direction (TD), in contrast to a strong anisotropy of Sr-free alloy. We comparatively investigated the effect of trace Ce, Sm and Sr addition on the microstructure, texture evolution and mechanical properties of rolled ATXM5210 alloy. Specially, Sr-containing alloy possesses a more uniform distribution of finer CaMgSn particles after rolling, whereas coarse particles and particle bands are still distinctive in Sr-free alloys. Furthermore, the addition of Sr contributes to form broader-distributed texture towards both RD and TD with reduced peak intensity (∼10.8), leading to an apparently reduced mechanical anisotropy. The quite low mechanical anisotropy and balanced combination of yield strength (∼220 MPa) and ductility (∼21 %) make the present ATXM5210-0.05Sr alloy suitable for producing intermediate or final products and competitive for various engineering applications.

The promotion of NH3-SCR performance and its mechanism on Sm modified birnessite

To develop novel NH3-SCR catalysts with low-temperature and high-efficency, a series of birnessite (δ-MnO2) catalysts with different Sm doping by methanol reduction are synthesized. The results showed that the introduction of Sm successfully inhibited the crystallization of MnOX, promoted the specific surface area, the contents of chemisorbed oxygen species and the formation of surface acid sites. It also increased the relative content of (Mn4+ + Mn3+)/Mn, which was beneficial to low-temperature SCR activity. The catalytic performance of xSm/Mn (δ-MnO2 based with xSm doping) catalysts was evaluated by NH3-SCR performances. Among them, 0.05 Sm/Mn showed 100% NOX conversion and high N2 selectivity compared to the other Sm addition catalysts within the operating low-temperature window (25–200 °C), at a high GHSV (gas hourly space velocity) of 60,000 h−1. The modified 0.05 Sm/Mn catalysts followed the L-H and E-R reaction mechanisms and were dominated by L-H, as revealed by in-situ DRIFTs analysis.

Investigation of Sm Addition on Microstructural and Optical Properties of CoFe Thin Films.

CoFe-based alloys and rare earth (RE) elements are among the most studied materials in applying magnetic devices to improve soft magnetic characteristics. A series of Co40Fe40Sm20 films are deposited on a glass substrate via the sputtering technique, followed by an annealing process to investigate their effect on microstructural and optical properties of Co40Fe40Sm20 films. In this study, the increase in the thickness of Co40Fe40Sm20 films and annealing temperatures resulted in a smoother surface morphology. The 40 nm Co40Fe40Sm20 films annealed 300 °C are expected to have good wear resistance and adhesive properties due to their high values of H/E ratio and surface energy. Optical transparency also increased due to the smoother surface of the Co40Fe40Sm20 films.

Exploring the trace rare earth Sm on the microstructure and mechanical performance of brazed diamonds by Ni–Cr filler alloy

In this study, the properties of Ni-based filler alloy are improved by adding rare earth Sm to them and brazing them at a temperature of 1080 °C. Relevant tests are carried out on filler alloy and brazed joints by means of electron microscopy (SEM), energy spectroscopy (EDS) and X-ray diffractometry (XRD). The results show that the addition of rare earth Sm can refine the grain of the filler alloy, improve the hardness of the filler alloy and reduce the thermal damage of the diamond after welding. The addition of rare earth Sm affects the diffusion of Cr, which reacts with the diamond at the interface to form Cr3C2 and Cr7C3, and the formation of these two carbides improves the bonding strength between the filler alloy and the diamond. When the addition of rare earth Sm is 1.5 wt%, the melting point of the filler alloy is the lowest, the grain refinement is the best, the hardness is the highest, and the thermal damage of the brazed sample is the lowest. In addition, the filler alloy of 1.5 wt%Sm has the greatest effect on the diffusion of the Cr element, the bonding strength between the filler alloy and diamond is the highest, and the mechanical properties of the brazed specimens are the best.

Effect of Sm + Er and Heat Treatment on As-Cast Microstructure and Mechanical Properties of 7055 Aluminum Alloy.

The 7055 aluminum alloy is an ultra-high strength aluminum alloy, which is widely used in the aerospace field and new energy automobile manufacturing industry. As it retains high strength, its plastic deformation ability needs to be improved, which limits its application in plastic processing. In this study, the cast grains of the 7055 aluminum alloy were refined by adding Sm + Er, and the proper heat treatment procedure was utilized to further precipitate the rare earth phase in order to increase the alloy's strength and toughness. The grain size, microstructure and phase were characterized by optical microscopes (OMs), scanning electron microscopy-energy spectrum (SEM-EDS) and a XRD diffractometer (XRD). The macroscopic hardness, yield strength and tensile strength of alloy materials were measured by a hardness meter and universal electronic tensile machine. The results showed that the as-cast sample and the heat treatment sample all contained Al10Cu7Sm2 and Al8Cu4Er rare earth phases. But, after heat treatment, the volume percentage of the rare earth phase dramatically increased and the dispersion was more unified. When 0.3 wt.%Sm and 0.1 wt.%Er were added, the grain size could be refined to 53 μm. With the increase in the total content of rare earth elements, the refining effect first increased and then decreased. Under 410 °C solid solution for 2 h + 150 °C and aging for 12 h, the macroscopic hardness, yield strength, tensile strength and elongation of 0.3 wt.%Sm + 0.1 wt.%Er + 7055 as-cast samples were 155.8 HV, 620.5 MPa, 658.1 MPa and 11.90%, respectively. After the addition of Sm and Er elements and heat treatment, the grain refinement effect of 7055 aluminum alloy was obvious and the plastic property was greatly improved under the premise of maintaining its high-strength advantage.