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oe1(光电查) - 科学论文

7 条数据
?? 中文(中国)
  • Wear and Corrosion Resistance of Al0.5CoCrCuFeNi High-Entropy Alloy Coating Deposited on AZ91D Magnesium Alloy by Laser Cladding

    摘要: In order to improve the wear and corrosion resistance of an AZ91D magnesium alloy substrate, an Al0.5CoCrCuFeNi high-entropy alloy coating was successfully prepared on an AZ91D magnesium alloy surface by laser cladding using mixed elemental powders. Optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction were used to characterize the microstructure of the coating. The wear resistance and corrosion resistance of the coating were evaluated by dry sliding wear and potentiodynamic polarization curve test methods, respectively. The results show that the coating was composed of a simple FCC solid solution phase with a microhardness about 3.7 times higher than that of the AZ91D matrix and even higher than that of the same high-entropy alloy prepared by an arc melting method. The coating had better wear resistance than the AZ91D matrix, and the wear rate was about 2.5 times lower than that of the AZ91D matrix. Moreover, the main wear mechanisms of the coating and the AZ91D matrix were different. The former was abrasive wear and the latter was adhesive wear. The corrosion resistance of the coating was also better than that of the AZ91D matrix because the corrosion potential of the former was more positive and the corrosion current was smaller.

    关键词: laser cladding,wear,AZ91D magnesium alloy,high-entropy alloy coating,corrosion

    更新于2025-11-21 11:24:58

  • A study of metallurgy and erosion in laser surface alloying of AlxCu0.5FeNiTi high entropy alloy

    摘要: AlxCu0.5FeNiTi high entropy alloy coating is synthesized by premixed high purity Cu, Fe, Ni and Ti powders on AA1050 aluminium substrate by laser surface alloying, with the aim to improve microhardness and erosion rate. Phase constituents, microstructure and microhardness were investigated using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Vickers Microhardness tester, respectively. The erosion behavior of AlxCu0.5FeNiTi coating is checked using an air jet erosion setup. SEM images show presence of three regions. Percentage compositions of these regions are evaluated using Energy Dispersive Spectroscopy. XRD analysis of AlxCu0.5FeNiTi coating confirmed that these regions are a mixture of disordered BCC and two FCC solid solution phases. The microhardness of the AlxCu0.5FeNiTi HEA is 18 times that of the AA1050 aluminium substrate. Results show that AlxCu0.5FeNiTi HEA coating has improved erosion resistance.

    关键词: Laser Surface Alloying,Microhardness,Microstructure,High Entropy Alloy,Erosion rate

    更新于2025-11-21 11:18:25

  • Precipitation behavior of selective laser melted FeCoCrNiC0.05 high entropy alloy

    摘要: Interstitial elements are e?ective to strengthen high entropy alloys (HEAs). In this work, FeCoCrNiC0.05 was prepared by selective laser melting (SLM) followed by annealing. The e?ects of annealing on the microstructures and mechanical properties of the SLMed FeCoCrNiC0.05 were investigated. Results show that, nano-scale Cr23C6-type carbides can precipitate under annealing conditions, leading to higher yielding strength. The SLMed FeCoCrNiC0.05 annealed at 1073 K for 0.5 h has a yielding strength of 787 MPa and an elongation of 10.3%. Precipitation kinetics in SLMed FeCoCrNiC0.05 has been established according to Avrami formula. The high strength can be attributed to solid solution hardening, precipitation hardening and cell-like structures.

    关键词: Precipitation kinetics,Hardening mechanism,Selective laser melting,Mechanical properties,High entropy alloy

    更新于2025-11-14 17:04:02

  • In situ TiN-reinforced CoCr2FeNiTi0.5 high-entropy alloy composite coating fabricated by laser cladding

    摘要: The fcc structural CoCr2FeNiTi0.5 high-entropy alloy (HEA) composite coating with TiN particles reinforced was acquired by laser cladding on the commercial 904L stainless steels. The results show that phase structure is mainly composed of fcc solid solution and TiN phases. The coating exhibits excellent structural stability below 850 °C. The microstructure consists of irregular dendrite and TiN particles. Transmission electron microscopy (TEM) results reveal that the close-packed plane of fcc phase is (111) with interplanar spacing of * 0.208 nm. The interface between TiN and fcc matrix is semi-coherent. And the angle of boundary between dendrite and matrix is * 65°. The hardness and corrosion resistance of coating have much improvement compared with those of substrate.

    关键词: Semi-coherent interface,High-entropy alloy,Laser cladding,TiN particle reinforced

    更新于2025-09-23 15:22:29

  • Microstructure and properties of CeO2-doped CoCrFeMnNi high entropy alloy fabricated by laser metal deposition

    摘要: Rare earth elements are usually regarded as e?cient additives for property enhancement of many types of alloys. In the present study, the CoCrFeMnNi high entropy alloy (HEA) was doped with CeO2, and such composites were for the ?rst time obtained by the laser metal deposition (LMD) process. The microstructure, phase compositions, microhardness and crystallographic texture of the HEA/CeO2 composites were investigated. It was demonstrated that CoCrFeMnNi HEA/CeO2 samples were successfully obtained by the LMD process. Meanwhile, small irregular shape oxides rich in Mn and Cr were observed in the HEA/ CeO2 composite. Rare earth element Ce was found to be evenly distributed throughout the sample. Heterogeneous dendritic microstructure with a long columnar grains oriented along the build direction was observed. The measured average microhardness is 181.72 ± 9.72 HV0.1.

    关键词: Composite,CeO2,High entropy alloy,Laser metal deposition,Additive manufacturing,CoCrFeMnNi

    更新于2025-09-23 15:21:01

  • Fatigue behaviour of a laser beam welded CoCrFeNiMn-type high entropy alloy

    摘要: Laser beam welding was used to produce butt joints from the CoCrFeNiMn-type high entropy alloy. The alloy in the initial condition had an fcc single-phase coarse-grained structure. Laser welding resulted in the M7C3-type carbides precipitation in the fcc matrix. The carbide particles precipitation resulted in a considerable increase in microhardness from 150 HV 0.5 for the as-sintered condition to 205 HV 0.5 in the fusion zone. Laser beam welding had a negligible effect on both static mechanical properties and fatigue behaviour of the alloy. The endurance limit of either type of specimens (i.e. with and without welding seam) was 200 MPa. Fracture of all specimens with the laser beam welded seams occurred in the base material area during both tensile and fatigue testing. Weak effect of welding on static/fatigue behaviour of the alloy can be attributed to the higher hardness of the fusion zone, resulting in strain localization in the base material area. An increase in load resulted in activation of secondary slip systems and formation of deformation twins in fatigue specimens.

    关键词: Fatigue,Tensile strength,Microstructure,Laser beam welding,High entropy alloy

    更新于2025-09-16 10:30:52

  • Preparation of Amorphous Coatings of AlFeCoNiCuZrV Alloy by Direct Current Magnetron Sputtering Method

    摘要: The amorphous coatings of AlFeCoNiCuZrV high entropy alloy were deposited by direct current magnetron sputtering (DCMS) in the mixed atmosphere of Ar and O2. A smooth amorphous coating was obtained. The microstructure and properties of the coatings were investigated. The results showed that the chemical composition, microstructure and mechanical properties of the amorphous coatings intimately relied on the concentration of O2 in the mixture atmosphere. When O2 flow ratio increased, the thickness and roughness of the coatings decreased. The maximum values of the hardness and the elastic modulus of the coating are 12 and 168 Gpa, respectively.

    关键词: Properties,Amorphous coating,Magnetron sputtering,High entropy alloy

    更新于2025-09-09 09:28:46