| LI Yongfeng,LIU Meiqin,WANG Lixia,LI Xiaoying,WU Ning,ZHANG Jian.Effect of Cr3C2 Content on Microstructure and Properties of Fe0.5CoCr0.5Mo0.3Ni High-entropy Alloy Remelting Coating[J],53(21):176-186 |
| Effect of Cr3C2 Content on Microstructure and Properties of Fe0.5CoCr0.5Mo0.3Ni High-entropy Alloy Remelting Coating |
| Received:April 16, 2024 Revised:July 05, 2024 |
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| DOI：10.16490/j.cnki.issn.1001-3660.2024.21.018 |
| KeyWord:HEA coating phase composition microstructure microhardness wear resistance corrosion resistance |
| Author | Institution |
| LI Yongfeng |
College of Mechanical and Electrical Engineering, Shandong University of Aeronautics, Shandong Binzhou , China |
| LIU Meiqin |
College of Mechanical and Electrical Engineering, Shandong University of Aeronautics, Shandong Binzhou , China |
| WANG Lixia |
College of Mechanical and Electrical Engineering, Shandong University of Aeronautics, Shandong Binzhou , China |
| LI Xiaoying |
Binzhou Special Equipment Inspection & Research Institute, Shandong Binzhou , China |
| WU Ning |
Binzhou Ecological Environment Service Center, Shandong Binzhou , China |
| ZHANG Jian |
College of Mechanical and Electrical Engineering, Shandong University of Aeronautics, Shandong Binzhou , China |
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| Abstract: |
| High-entropy alloy (HEA) is an alloy formed by five or more main metal elements. Due to its many excellent properties, it has been widely concerned in the fields of material science and engineering application. However, the presence of a multitude of elements within these alloys can lead to the formation of brittle intermetallic compounds or intricate intermediate phases, such as the laves phase, which leads to the deterioration of the alloy properties. To expedite the industrial utilization of HEAs, it is imperative to refine their properties through various methods to enhance their performance and mitigate existing deficiencies. Drawn from metallurgical expertise, carbon and carbides are recognized for their pivotal role in modulating the properties of steel. It is anticipated that these elements will exert a substantial effect on the attributes of HEAs as well. It is concluded that carbon and carbide will also have a significant impact on the properties of HEAs. Therefore, the work aims to prepare HEAs-carbide composite coating by adding different contents of Cr3C2 to Fe0.5CoCr0.5Mo0.3Ni HEAs, and discuss the effects of Cr3C2 on the phase composition, microstructure, microhardness, wear resistance and corrosion resistance of the coating. Before coating fabrication, the powder with the ratio of Fe0.5CoCr0.5Mo0.3Ni-xCr3C2 (x = 0%, 7.5%, 10%, 20%) was mechanically mixed by planetary ball mill and preset on the polished 45# steel plate. The coating was prepared by 3 kW laser cladding equipment (LATEC LOM-3000) under the condition of 1.5 kW laser power, and remelted by 0.8 kW laser beam. The microhardness of cladding layer was measured by microhardness tester (HXD-1000TMC/LCD). The phase composition of different coatings was qualitatively analyzed by X-ray diffractometer (Bruker, D8 Advanced, XRD). The microstructure of the coating was observed by scanning electron microscope (Nova Nano 450 SEM), and the distribution of elements in the coating was quantitatively analyzed by energy dispersive spectrometer (EDS). Impedance and polarization curves were measured in 3.5% NaCl solution by electrochemical workstations (PASSTAT 2273 and CHI660E). The friction and wear properties of different coatings were tested by RETC friction and wear tester, and the three-dimensional morphology of wear marks was observed and compared by three-dimensional profilometer (BRUKER GTK-20-1045). The main phase of the coating was FCC HEAs phase with Fe-Co-Cr-Ni-Mo as the main element. With the increase of Cr3C2 content, the content of (Cr, Fe)23C6 in the coating gradually increased, while there was a small amount of M2C(M:Fe, Co, Mo) phase. The addition of Cr3C2 also changed the laves content, but the laves content was too small to be reflected in the XRD data. The microstructure of the coating without Cr3C2 was typical dendrite and reticular interdendritic structure, and a few columnar crystals were also found. With the increase of Cr3C2 content, the microstructure of the coating was gradually refined, and the morphology of the grain changed from coarse dendrite to fine block and cylindrical dendrite. In the process of laser cladding, Cr3C2 consumed laves phase to form (Cr, Fe)23C6 and M2C, which changed the microstructure in the coating and generated more acicular or lath-like structures. When Cr3C2 increased to 20%, because laves might be exhausted, acicular crystals grew in disorder and formed eutectic structure composed of carbide and FCC. With the increase of Cr3C2 content, more hard phases such as (Cr, Fe)23C6 and M2C (M:Fe, Co, Mo) were formed in the coating, which significantly improved the microhardness of the coating, reduced the friction and wear coefficient and improved the wear resistance of the coating. The addition of Cr3C2 also affected the electrochemical impedance and corrosion resistance of the coating. The coating with 20% Cr3C2 had the minimum self-corrosion current density and the highest self-corrosion potential, which were 37.25 nA/cm2 and –0.15 V respectively, and had the largest impedance curve radius and the largest impedance value. The addition of Cr3C2 will affect the phase composition, phase content, microstructure, morphology, wear resistance and corrosion resistance of Fe0.5CoCr0.5Mo0.3Ni coating. When the content of Cr3C2 is in the range of 0%-20%, the more Cr3C2, the better the wear resistance and corrosion resistance of the coating. The amount of Cr3C2 cannot be added indefinitely. Too high carbide content will increase the probability of cracks in the coating and reduce the mechanical properties. Therefore, the optimal amount of Cr3C2 will be further explored in the future study, and its effect on the mechanical properties of the coating will be studied. |
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