Materials Chemistry and Physics最新文献

{"title":"Colloidal lithography: Synthesis and characterization of SiO2 and TiO2 micro-bowel arrays","authors":"Farzaneh Bayat ,&nbsp;Zahra Sadeghi Farshi ,&nbsp;Maliheh Sadat Arab Jafari ,&nbsp;Maryam Sharifi ,&nbsp;Pouria Chaghamirzaei ,&nbsp;Ali Reza Amani-Ghadim ,&nbsp;Kazem Jamshidi-Ghaleh","doi":"10.1016/j.matchemphys.2024.130206","DOIUrl":"10.1016/j.matchemphys.2024.130206","url":null,"abstract":"<div><div>Recent interest has surged in engineering surface structures at nano/micro scales using accessible and cost-effective techniques, owing to their wide-ranging applications. In this study, we fabricated ordered arrays of TiO₂ and SiO₂ micro-bowels utilizing the colloidal lithography method and delved into their optical properties. Initially, we synthesized polymethyl methacrylate (PMMA) microspheres with an average diameter of 409 nm via the emulsion polymerization method. Ensuring crack-free and well-organized 2D colloidal crystals as the lithography template is crucial for achieving high-quality and systematically arranged micro-bowel arrays. Therefore, we explored two distinct methods for fabricating 2D colloidal PMMA crystals, namely the Langmuir−Blodgett trough and gravity-assisted wedge-shaped cell techniques, and compared their outcomes. Subsequently, we introduced a specific amount and concentration of TiO₂/SiO₂ precursor into the templates. Upon removal of the polymeric template through calcination and chemical etching, the micro-bowel array persisted on the substrate surface. We thoroughly investigated the influence of the template fabrication method on the quality of the final microstructures. Our analyses affirm that the Langmuir−Blodgett technique yields higher-quality micro-bowels in a shorter duration. The ordered structures and high surface-to-volume ratio of the micro-bowels render them suitable candidates for various applications including photocatalysis, solar cells, bio/chemical sensors, and more.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"332 ","pages":"Article 130206"},"PeriodicalIF":4.3,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduced graphene oxide – CeO2 nanocomposites for photocatalytic dye degradation","authors":"Asifur Rahman,&nbsp;Jannatul Naime,&nbsp;Md. Ahsan Habib,&nbsp;S.M. Imran Ali,&nbsp;Md. Mahiuddin,&nbsp;Kaykobad Md Rezaul Karim","doi":"10.1016/j.matchemphys.2024.130210","DOIUrl":"10.1016/j.matchemphys.2024.130210","url":null,"abstract":"<div><div>Over the past few decades, the widespread use of dyes has led to considerable environmental pollution, posing serious threats to human health and ecosystems. In this context, here focus on a tailored nanocomposite comprising reduced graphene oxide (rGO) and cerium oxide (CeO₂) to eradicate methylene blue (MB) dye. The fabrication process involves a facile synthesis wherein CeO₂ nanoparticles are anchored onto rGO sheets through co-precipitation treatment by mixing a precursor salt of cerium with graphene oxide (GO) in presence of reducing agent. The resulting nanocomposites were characterized using X-ray diffraction (XRD) analysis which confirms the crystallite size of CeO₂ and rGO-CeO₂ determined to be 21.61 nm and 10.74 nm respectively. Further FE-SEM analysis vividly illustrates the relatively spherical form of CeO₂, which is dispersed on the rGO surface and energy dispersive X-ray spectroscopy (EDX) results provide clear evidence of the presence of carbon, cerium and oxygen in the composite. Additionally, Fourier-transform infrared spectroscopy (FTIR) confirms the composition of the rGO-CeO₂ nanocomposites demonstrating the existence of various oxygen-containing groups, including O–H, C=O and Ce–O bonds. Thermogravimetric analysis (TGA) highlights that the rGO-CeO₂ nanocomposites exhibits higher thermal stability with only 21.88 % weight loss up to 400 °C. Moreover, the photocatalytic activity of rGO-CeO₂ nanocomposite exhibits a remarkable 94.92 % degradation of MB dye within 80 min under optimal conditions of UV light irradiation (λ = 254 nm), with a catalyst dosage of 7 mg in a 20 ppm of MB dye solution at pH 9. In contrast, pristine rGO and CeO₂ achieved only 32.27 % and 38.48 % in 100 and 90 min respectively. The kinetics of photocatalysis process were meticulously studied and revealed that they followed pseudo-second order kinetic model suggesting chemisorption of MB dye onto nanocomposites prior to degradation. The stability of the nanocomposite was assessed under optimal conditions, demonstrating robust MB degradation (78 %) even up to the 4th cycle. Overall, the successful outcomes of this study show significant potential for degrading MB dye in wastewater by using the rGO-CeO₂ nanocomposite.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"332 ","pages":"Article 130210"},"PeriodicalIF":4.3,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of V2O5 coatings on NMC 111 battery cathode materials in aqueous process","authors":"Joel Obed Herrera-Robles ,&nbsp;Milad Azami-Ghadkolai ,&nbsp;Rajendra Kumar Bordia ,&nbsp;Hector Camacho-Montes ,&nbsp;Claudia Alejandra Rodríguez-Gonzalez ,&nbsp;Yoanh Espinosa-Almeyda ,&nbsp;Pierre Giovanni Mani-Gonzalez","doi":"10.1016/j.matchemphys.2024.130188","DOIUrl":"10.1016/j.matchemphys.2024.130188","url":null,"abstract":"<div><div>In this study, we focused on the effect of different percentages of <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> coating on the chemical stability of NMC 111. Stability and leaching studies were conducted in solutions at varying pH levels to quantify the influence of coating percentage and exposure conditions on chemical stability. Our findings indicate effective protection of NMC 111. The slurries containing coated particles remain stable across acidic, neutral, and basic pH ranges. This observation provides a broad aqueous processing window for coated NMC 111, preventing lithium-ion leaching. For the uncoated samples, the measured pH consistently remained in the basic range, regardless of the initial pH, indicating a strong reaction between NMC 111 and water that leads to the formation of hydroxides. In contrast, for the coated samples, the reaction predominantly involves <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span>. The thicker <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> coatings (3% and 4% by weight) are particularly effective in reducing lithium leaching. XRD analysis suggests that the <span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> coating helps minimize cation mixing. XPS, TEM, and SEM-EDS morphological characterization were performed to confirm the presence of the coating on the surface of the samples. Additionally, the coating percentage and its effect on charge transfer resistance in sintered samples were discussed and analyzed using EIS with Ag as an ion-blocking agent.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"332 ","pages":"Article 130188"},"PeriodicalIF":4.3,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural modification of MgO/Au thin films by aluminum Co-doping and related studies on secondary electron emission","authors":"Yue Su ,&nbsp;Jie Li ,&nbsp;Biye Liu ,&nbsp;Xuming Chu ,&nbsp;Shengli Wu ,&nbsp;Wenbo Hu ,&nbsp;Guofeng Liu ,&nbsp;Tao Deng ,&nbsp;Haodong Wang","doi":"10.1016/j.matchemphys.2024.130209","DOIUrl":"10.1016/j.matchemphys.2024.130209","url":null,"abstract":"<div><div>The secondary electron emission (SEE) has the potential applications in electron multiplication, mass spectrometer, scanning electron microscope, photomultiplier tubes and so on. Among these, the electron multiplier (EM) based on MgO/Au thin film has attracted great attention over the past few years. Here, we design a new kind of MgO thin film by co-doping of gold and aluminum elements based on the structural modification through reactive magnetron sputtering method. The doping of Al into MgO/Au film gives a rise to the maximum SEE coefficient (<em>δ</em>_max) between 9.02 and 10.23 while the optimal decay rate is around 10.4 % after 2 h of consistent electron bombardment. Herein, we also improved the stability of the film stored in air by sputtering Al₂O₃ layer on it. For the sample sputtered with the protecting layer Al₂O₃, its SEE coefficient (<em>δ</em>) at the incident electron energy of 200 eV still kept at a relatively high level that exceed 4.5 after stored in air for 72 h. The film properties after Al and Au co-doping are investigated in detail by the SEM, AFM, XPS and UV-VIS spectroscopy. Our results provide a new candidate for SEE layer in the application of long lifespan vacuum electron devices.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"332 ","pages":"Article 130209"},"PeriodicalIF":4.3,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of ZrB2 on microstructure and wear properties of TC4 alloy coatings by laser direct energy deposition","authors":"Chunlun Chen ,&nbsp;Zhenlin Zhang ,&nbsp;Xin Zhang ,&nbsp;Jinghao Zhuang ,&nbsp;Yongsheng Zhao ,&nbsp;Yan Liu ,&nbsp;Shuangquan Guo ,&nbsp;Hui Chen","doi":"10.1016/j.matchemphys.2024.130208","DOIUrl":"10.1016/j.matchemphys.2024.130208","url":null,"abstract":"<div><div>In this paper, ZrB₂/TC4 alloy coatings with different contents of ZrB₂ were prepared on the surface of TC4 titanium alloy using laser direct energy deposition technology. The effects of ZrB₂ content on the microstructure, phase, microhardness and friction and wear behaviors of the TC4 coating were investigated, and the enhancement mechanism of ZrB₂ on the coating properties was analyzed. The results show that with the increase of ZrB₂ content, the coating successively produces the white ring-like structure of the first and the last, the parallel structure of the fishbone and the staggered structure of the TiB compounds, and the microstructure of the coating is transformed from the elongated grains to the fine grains. The microhardness and wear rate of the 15 wt% ZrB₂/TC4 coating reached up to 352.1HV and 5.9 × 10−⁶ g/N•m, respectively. Compared with the 100%TC4 coating, the microhardness is increased by 14.6 % and the wear rate is decreased by 52.0 %, indicating that the addition of ZrB₂ was beneficial to improve the friction and wear properties of coating. Interestingly, when the content of ZrB₂ reached 20 %, the brittleness of the coating was too high, leading to the phenomenon of grooves on the wear surface of the coating, and the wear rate was reduced by only 45.5 %.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"332 ","pages":"Article 130208"},"PeriodicalIF":4.3,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationship between the shear modulus and volume relaxation in high-entropy metallic glasses: Experiment and physical origin","authors":"R.S. Khmyrov ,&nbsp;A.S. Makarov ,&nbsp;J.C. Qiao ,&nbsp;N.P. Kobelev ,&nbsp;V.A. Khonik","doi":"10.1016/j.matchemphys.2024.130184","DOIUrl":"10.1016/j.matchemphys.2024.130184","url":null,"abstract":"<div><div>We performed parallel measurements of the high-frequency shear modulus <span><math><mi>G</mi></math></span> and relative volume <span><math><mrow><mi>Δ</mi><mi>V</mi><mo>/</mo><mi>V</mi></mrow></math></span> for high-entropy Ti₂₀Zr₂₀Hf₂₀Be₂₀Cu₂₀ and Ti₂₀Zr₂₀Hf₂₀Be₂₀Ni₂₀ glasses upon heating from room temperature up to the complete crystallization. The changes of these properties due to structural relaxation both below and above the glass transition temperature are singled out. It is shown that these changes for both initial and preannealed samples can be well described within the framework of the Interstitialcy theory. It is found that the whole relaxation process in the full temperature range of the experiments for both samples’ states can be characterized by a single dimensionless temperature-independent parameter <span><math><mrow><msub><mrow><mi>K</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>=</mo><mi>d</mi><mi>l</mi><mi>n</mi><mspace></mspace><mi>G</mi><mo>/</mo><mi>d</mi><mi>l</mi><mi>n</mi><mspace></mspace><mi>V</mi></mrow></math></span>, which equals to −44 and −53 for the above glasses, respectively, and strongly points at interstitial-type defects as a source of the relaxation. We also show that relaxation of the relative volume linearly depends on the defect concentration. This behavior can be described by another dimensionless temperature-independent parameter, which is related with the relaxation volume of defects. It is shown that the obtained results provide resonable estimates of density changes upon crystallization. Possible contribution of vacancy-like defects into the relaxation is discussed.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"332 ","pages":"Article 130184"},"PeriodicalIF":4.3,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure, mechanical, and wear characteristics of heat-treated aerospace-grade aluminium composite reinforced with HEA particles","authors":"Pradip Kumar Verma ,&nbsp;Alok Singh ,&nbsp;Akshay Kumar ,&nbsp;Nisha Malik","doi":"10.1016/j.matchemphys.2024.130195","DOIUrl":"10.1016/j.matchemphys.2024.130195","url":null,"abstract":"<div><div>This research paper investigates the mechanical, microstructural, and wear characteristics of Al7075 composite reinforced with high entropy alloy particles. Stir casting, equipped with an ultrasonic probe, was used for the fabrication of the composite. Microstructural analysis including optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, and X-ray diffraction, was conducted assess the microstructure and dispersion of reinforced particles in the composite and alloy. Results indicated that hardness and tensile strength increased with higher weight percentages of reinforcement, while percentage elongation decreased. However, properties decreased with further reinforcement beyond 6 wt% in the composite. Mechanical testing revealed that heat treated composites with 6.0 wt% HEAp have maximum UTS and hardness of 287.6 MPa and 117.2 HRB, respectively. Fracture morphology analysis further provides insights into the interactions between the HEAp and the aluminium matrix, shedding light on crack initiation, propagation, and the role of HEAp in influencing the fracture mechanisms. A comprehensive examination of the worn surface was conducted using SEM and an optical profilo-meter.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"331 ","pages":"Article 130195"},"PeriodicalIF":4.3,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient photocatalytic removal of Cr6+ by steel slag loaded cellulose nanofiber aerogel","authors":"Yiming Dai ,&nbsp;Boting Yan ,&nbsp;Yixin Li ,&nbsp;Mingyang Li ,&nbsp;Hao Zhang ,&nbsp;Xiangpeng Gao","doi":"10.1016/j.matchemphys.2024.130191","DOIUrl":"10.1016/j.matchemphys.2024.130191","url":null,"abstract":"<div><div>Hexavalent chromium (Cr⁶⁺), a notorious toxicant and carcinogen in industrial wastewater, poses severe health hazards. Traditional photocatalytic materials, effective primarily with ultraviolet light, have limited practical application due to their inefficiency under visible light. This study presents an innovative composite, polyethyleneimine-modified nanocellulose aerogel loaded with steel slag (SS/PCNFA), which demonstrates superior Cr⁶⁺ reduction under visible light. Our experiments reveal that SS/PCNFA achieves an impressive Cr⁶⁺ removal efficiency of 96.4 % within a mere 40 min, with the potential for complete removal within 45 min, starting from an initial concentration of 100 mg/L. Kinetic analysis confirms that the adsorption process adheres to a second-order model with an R² value of 0.9985, indicating a high degree of fit. Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses affirm the presence of nitrogen and hydroxyl functional groups that actively participate in the reduction process. Thermodynamic analysis indicates that the adsorption process is endothermic, with excellent fitting to both Langmuir and Freundlich isotherms, suggesting a combination of monolayer and multilayer adsorption mechanisms. Under optimal conditions, SS/PCNFA has proven to be exceptionally effective in reducing Cr⁶⁺ levels, showcasing its promising potential for the remediation of industrial wastewater.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"332 ","pages":"Article 130191"},"PeriodicalIF":4.3,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of strain and doping on Li-ion transport in Li3OBr0.5Cl0.5 anti-perovskite solid lithium-ion electrolytes: Insights from DFT and AIMD calculations","authors":"Guoyu Huang ,&nbsp;Ying Yan ,&nbsp;Lin Zhang ,&nbsp;Yi Dong","doi":"10.1016/j.matchemphys.2024.130202","DOIUrl":"10.1016/j.matchemphys.2024.130202","url":null,"abstract":"<div><div>The impact of applying strain on the Li-ion transport characteristics of Li₃OBr_0.5Cl_0.5 anti-perovskite solid lithium-ion electrolytes with different doping positions have been systematically studied within the framework of density functional theory. We have examined the changes in bandgap, defect formation energy, and Li-ion migration barrier under triaxial compressive and tensile strains, spanning from −4% to 4 %. Following, by calculating of the diffusion and conductivity of different structures of Li₃OBr_0.5Cl_0.5, we have screened out one structure (Br-ions and Cl-ions are diagonally distributed at each vertex of the lattice) with the highest conductivity at room temperature from six structures of Li₃OBr_0.5Cl_0.5. Afterward, the changes of diffusion, conductivity and MSD of the structure with the highest conductivity at room temperature under applying −4% and 4 % triaxial strains have been studied. The results reveal intriguing implications: Tensile strains increase the defect formation energy for both Li-ion vacancies and Li interstitials, while simultaneously lowering the migration barrier of Li-ion. The influences of the formation energy and migration barrier significantly enhance the conductivity of Li-ion. This consequence is confirmed by AIMD simulation that both diffusivity and conductivity are enhanced under applying tensile strains, while an opposing effect observed under applying compressive strains. These findings unequivocally demonstrate that strains exert a profound influence on Li-ion conductivities in Li₃OBr_0.5Cl_0.5 anti-perovskite electrolytes. Specifically, the application of tensile strain emerges as a promising strategy to augment lithium-ion transport.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"332 ","pages":"Article 130202"},"PeriodicalIF":4.3,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of laser surface melting on microstructure and hardness of Mg–4Y–2Zn–1Zr-0.6Ca alloy","authors":"Paria Nemati,&nbsp;Homam Naffakh-Moosavy,&nbsp;Alireza Sabour Rouhaghdam","doi":"10.1016/j.matchemphys.2024.130204","DOIUrl":"10.1016/j.matchemphys.2024.130204","url":null,"abstract":"<div><div>To improve the performance of magnesium and enhance its mechanical properties and microstructure, a laboratory-scale Mg alloy with the composition Mg–4Y–2Zn–1Zr-0.6Ca was developed. Subsequently, the alloy was subjected to homogenization and extrusion processes to reduce casting defects and the microstructure refinement. Additionally, surface modification was performed using a pulsed Nd:YAG laser. The findings of the experiment indicate that by controlling the laser processing parameters, it was possible to attain a microstructure devoid of any defects. Moreover, an examination of the microstructure and secondary phases was conducted through the utilization of characterization techniques such as the Optical Microscope (OM), Field Emission Scanning Electron Microscope (FESEM) equipped with Energy Dispersive Spectroscopy (EDS), and X-ray Diffraction (XRD). Furthermore, the micro hardness of the samples was evaluated using the Vickers micro hardness testing method. Consequently, the microstructures of all specimens exhibited equiaxed grains, predominantly composed of (α-Mg), (Mg₂₄Y₅+α-Zr), and the W-phase (Mg₃Y₂Zn₃). In addition, the laser-melted surface revealed a noteworthy refinement of the grain structure, with an evolution in grain morphology from the top to the bottom of the melted area. Equiaxed grains were present in the centerline, whereas columnar grains were observed in the fusion line. Additionally, as the scanning speed increased, a finer microstructure was observed. Due to the rapid heating and cooling involved in the laser surface melting (LSM) process, the secondary phase (Mg₃Y₂Zn₃) dissolved in the microstructure, and the (Mg₂₄Y₅+α-Zr) phase was uniformly distributed throughout the LSMed area. Ultimately, the micro hardness showed a significant increase due to the dual influence of grain refinement and the homogeneous dispersion of the secondary phase.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"332 ","pages":"Article 130204"},"PeriodicalIF":4.3,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}