M2052 (Mn-20Cu-5Ni-2Fe, at.%) damping alloy was fabricated by laser powder bed fusion (LPBF). Its microstructure, mechanical properties, and damping behavior were investigated after direct aging and solution treatment followed by aging, with the aim of achieving a simultaneous improvement in mechanical performance and damping capacity. The results show that, compared with the as-built condition, direct aging markedly enhances the strength of the alloy, with the ultimate tensile strength reaching approximately 708 MPa, the yield strength increasing to about 469 MPa, and the elongation remaining at 25.7%. Solution treatment significantly improves the ductility of the M2052 alloy, with the elongation reaching as high as about 40.6%. Damping tests indicate that direct aging effectively improves the room-temperature damping performance, with the maximum value increasing by nearly three times. The improvement in mechanical properties and damping capacity is mainly attributed to the beneficial effects of the spinodal structure and twin structures formed during heat treatment. This work provides a theoretical basis for heat-treatment design and property regulation of additively manufactured MnCu based damping alloy components.

Aiming at the issue of poor corrosion resistance in M2052 alloy and the damping performance degradation as the working temperature increases, this study focuses on enhancing the corrosion resistance of the M2052 damping alloy through a low-temperature (<60 °C) coating preparation method. A uniform Ni-W coating with a thickness of approximately 12 μm and a nanocrystalline structure was successfully obtained under a low current density condition. Compared with the uncoated substrate, the Ni-W-coated samples exhibited significantly enhanced hardness, reduced friction coefficient, and markedly improved wear resistance, with the dominant wear mechanism transitioning from abrasive/oxidative wear to mild adhesive wear. In 3.5 wt.

The M2052 alloy (Mn‐20Cu‐5Ni‐2Fe at%) exhibits excellent damping capacity and favorable mechanical strength, making it a promising candidate for vibration damping and energy absorption. However, its potential in lattice structures has not been reported to date. In this article, M2052 alloy lattice structures are fabricated via selective laser melting to evaluate their mechanical properties and energy absorption capabilities. Three lattice architectures with comparable relative densities are designed and manufactured: body‐centered cubic (BCC), BCC with vertical struts (BCCZ), and reinforced hollow BCCZ (RHBCCZ) featuring hollow struts and strengthening ribs. Quasi‐static compression tests and finite element simulations are conducted to analyze their mechanical responses and deformation mechanisms. Furthermore, the effects of heat treatment on the compressive properties and microstructural evolution of BCC lattices are investigated. Results demonstrate that the RHBCCZ structure delivers optimal performance, with a Young's modulus of 1506.3 MPa, yield strength of 18.41 MPa, and maximum energy absorption of 22.69 J cm −3 . Heat treatment enhanced the yield strength and altered the deformation mode of the lattice. This article highlights the potential of M2052 alloy in load‐bearing, energy‐absorbing, and lightweight structural applications.

M2052 (Mn-20Cu-5Ni-2Fe, at%) alloy is a high-damping alloy with excellent comprehensive properties, widely used in vibration and noise reduction applications. Selective Laser Melting (SLM) technology can overcome the limitations of traditional processes and efficiently and accurately manufacture complex parts. In this study, M2052 alloy specimens were fabricated using SLM in horizontal (H0 samples), inclined (I45 samples), and vertical (V90 samples) directions. The microstructure, tensile properties, fracture morphology, and corrosion performance of the three directions were investigated. The anisotropy of yield strength and corrosion performance among the three samples was discussed. The results show that, compared to the inclined and vertical samples, the horizontal samples exhibited the highest yield and tensile strengths, with the I45 samples having the highest elongation of 26.82%. The anisotropy of yield strength in different directions may be related to GND density, Taylor factor, and grain size. In 3.5 wt.% NaCl solution, the corrosion resistance of different planes varied in the order of H0 > I45 > V90. The anisotropy of corrosion resistance may be attributed to differences in the microstructure.

M2052 (Mn-20Cu-5Ni-2Fe, at.%) alloy is known for its excellent damping and mechanical properties, but its corrosion resistance is lacking. Here, a composite coating was developed by chemically plating a Ni-P amorphous coating followed by electroplating a superhydrophobic nickel (SH Ni) coating. The composite coating exhibits super-hydrophobic properties primarily for two reasons. Firstly, the pinecone-shaped structure on the surface of the Ni-P/SH Ni coating has the ability to trap air, thereby forming an air layer. Secondly, through surface modification with stearic acid molecules, there is a significant reduction in the surface energy of the coating. As a result, the Ni-P/SH Ni coating were effective in reducing the corrosion rate, which can be attributed to the effective filling of the surface pores of the Ni-P coating by the outer Ni film, and the superhydrophobic characteristics of the SH Ni coating. This study provides a new idea for corrosion protection of M2052 alloys in marine environment.

Vibration and noise reduction has always been important problem to be solved in the fields of rail transit, aerospace, marine engineering, and so on. In this paper, a novel Fe65-XMn20Cr15CoX (X = 5, 10, 15, 20) dual -phase high-entropy damping alloy with excellent properties were prepared by vacuum melting. The depen-dence of the alloy damping behavior on the twin interface, magnetic properties and phase interface was emphatically analysed. The effects of Co content on its microstructure, damping behavior and magnetic prop-erties were investigated. The results show that with the increase of Co content, epsilon martensite gradually transforms to gamma austenite, and the number of twins increases gradually. The peak damping (Q-1) increased from 0.0442 to 0.0595, an increase of 34.6%. The coupled effects of magneto-mechanical hysteresis, twin interface motion, and phase interface motion provide the alloy's excellent damping properties. The alloy has a higher damping internal friction peak of around 200 degrees C, which is due to the phase transition from epsilon to gamma at the temperature. By adjusting the Co content, the phase content and twinning and other microstructures of the alloy can be regulated, and multiple damping mechanisms can be coupled to achieve higher damping performance.

M2052 damping alloy has good shock absorption and noise reduction ability, but the corrosion resistance and wear resistance are insufficient. In this study, a high phosphorus amorphous Ni-P coating with a thickness of about 22.1 mu m was successfully deposited on the M2052 substrate by electroless plating. The wear experiments show that the main wear mechanism of Ni-P coating is adhesive wear, while the main wear mechanism of M2052 substrate is abrasive wear and corrosion wear. Compared with M2052 substrate, the electroless plating sample has a lower corrosion current and higher corrosion potential, and the corrosion resistance is greatly improved. In the erosion-corrosion environment, the corrosion rate of the uncoated sample is about 5 times that of the coated sample. However, the damage of Ni-P coating under the same environment corroded slightly, which effectively impedes the erosion of sediment flow and the corrosion of artificial seawater.

The Fe65-xMn20Cr15Cox (x = 0, 5, 10, 15) high entropy alloys (HEAs) were prepared by mechanical alloying (MA) and spark plasma sintering (SPS). The effects of the configurational entropy on the microstructure, magnetic properties, and damping behaviors were investigated in this paper. As the Co content increased, the configurational entropy of the HEAs was increased from 0.88R to 1.23R, the magnetology performance was reduced significantly, but the peak of internal friction (IF) Q-1 increased monotonously. The maximum internal friction (IF) Q-1max achieved 0.073 when 15 at% Co element was added. With the configurational entropy increasing, in addition to the ferromagnetic damping mechanism, the dislocation damping mechanism was introduced in the HEAs. The synergistic effect of magneto-mechanical hysteresis and dislocation energy dissipation ensured the FeMnCrCo HEAs maintained high damping performance in a wide strain amplitude. Through the regulation of the microstructure, the possibility of application of the damping alloy under extreme conditions can be expanded.

The CrMnFeCoNi-based composites with different multi-layer graphenes (MLGs) content (0 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%) were prepared by powder metallurgy. The effects of the MLGs content on the mechanical and damping properties of the composites were studied specifically. The strength and hardness are obviously improved, and the tensile strength can reach 762 MPa. With the addition of MLGs, new damping mechanisms including the intrinsic damping of graphene and the interface damping are introduced, which lead the damping properties of composites to remain at a high level. As the content of MLGs increases, the Maximum internal friction (Q(max)(-1))of the composites increases first and then decreases, and its maximum value is 0.0667. (C) 2021 Elsevier B.V. All rights reserved.

M2052 is a famous high damping Mn-Cu alloys with good strength, but lack of well corrosion and wear resistance. In this study, we expect to enhance the wear and corrosion resistance of M2052 damping alloys by electroless plating Ni-P coating. Successfully, a high phosphorus amorphous Ni-P coating with thickness about 15 pm plated on M2052 substrate. After electroless plating Ni-P coating, the roughness of samples surface decreased and the microhardness increased. Thus, the coated sample featured better wear resistance, and attributed to adhesive wear mechanism. By contrast, the friction coefficients of uncoated samples presented a high value with great fluctuations, which due to low hardness, high roughness, and easier to be oxidized. This leads to the dominant wear mechanisms are abrasive and corrosive wears. Ni-P coating significantly improved the corrosion resistance, because it has lower /(coo), higher E-corr, and higher impedance than M2052 substrate. Surface morphologies after electrochemical tests were also observed: the uncoated samples had been corroded severely with a fibrous corrosion product layer dispersing cracks and pits. However, coated samples had not been corroded and remains intact. Furthermore, Mott-Schottky plots inferred that the sample surface after plating Ni-P coating performed an excellent passivation behavior in NaCI solution.

The proposed parameters of Fe2 CrAl and FeCrAlSi,electronic density of states,magnetic moment and magnetic anisotropy energy,were calculated by using first-principles of density functional theory (DFT),gen-eralized gradient approximation (GGA)and full-potential linearized augmented plane wave (FP-LAPW).The calculation results show that damping category of Fe2 CrAl and FeCrAlSi are ferromagnetic.Ferromagnetic damping comes from spin-orbit interaction and d orbitals hybridization effects between the transition metal at-oms.The increase of total magnetic moment and the decrease of coercive force will cause that the ferromagnetic damping of FeCrAlSi was higher than Fe2 CrAl.

This paper studies the preparation of Fe-15Cr-3Mo-0.5Si alloy by using vacuum induction melting furnace and vacuum annealing furnace, the damping performance of which in different heat treatment states is tested with dynamic mechanical thermal analyzer (DMA). Through microstructure observation with metallographic microscope (OM), grain boundary observation with scanning electron microscopy (SEM), phase structure analysis with X-ray diffraction (XRD) and internal stress of S-B model analysis, the effect law of annealing temperature, types of cooling, holding time and grain sizes on the damping performance of alloy and the related mechanism can be concluded as follows. The annealing temperature and grain sizes have a significant impact on the damping strain amplitude as well as the magnetic and mechanical damping performance of this ferromagnetic alloy. Proper annealing temperature and grain size is the necessary condition to get high damping performance of the alloy. It is not conducive to improvement of the damping performance if the annealing temperature is too high or too low and the grain size is too small or too large. For Fe-15Cr-3Mo-0.5Si alloy, within the range of the low strain amplitude, alloy damping performance does not improve monotonously with the increase of the annealing temperature and grain size. The maximum value appears at the annealing temperature of 1100 degrees C/1 h with the grain size of about 300 mu m. At high annealing temperature of 1100 degrees C, the damping performance of alloy in the slow cooling furnace is higher than that with air cooling treatment. The extension or shortening of the holding time, to a certain extent, reduces the damping performance of the alloy. This alloy shows low damping performance after air cooling and cold working. (C) 2014 Elsevier B.V. All rights reserved.

研究了退火方式对N36锆合金包壳管再结晶程度、力学性能、收缩系数(CSR)、椭圆度以及腐蚀性能的影响.结果表明,在同一退火制度下,采用套管与不采用套管退火相比,管材再结晶程度、强度、CSR性能及短期腐蚀性能没有明显差异,伸长率有所下降;采用套管退火的管材椭圆度没有明显变化,而未采用套管进行退火的管材椭圆度增加明显.

This paper studied the damping performance of Fe–13Cr–2A1–1Si alloy with different heat treatments using dynamic mechanical thermal analyzer (DMA). The effect of heat treatment and grain size on the damping performance was investigated in detail. It was found that the annealing temperature and grain size have a significant impact on the damping strain amplitude of the alloy. Additionally, we found that heat treatment and grain size can improve the magnetic and mechanical damping performance of this ferromagnetic alloy. Proper annealing temperature and grain size is important to get high damping performance of the alloy. With low strain amplitude, the damping performance of Fe–13Cr–2Al–1Si alloy does not increase monotonously with the increase of the annealing temperature and grain size. The maximum value appears at the annealing temperature of 1100°C/1h with the grain size of about 300μm. At this annealing temperature, the damping performance with furnace cooling is higher than that with air cooling treatment. The extension or shortening of the holding time to a certain extent will reduce the damping performance of the alloy. Besides, this alloy shows low damping performance after air cooling and cold working.

Superior and inferior magnetic powders can be separated from the same batch crystallined NdFeB magnetic powders containing Zr and Co elements by magnetic separation method due to their magnetic ununiformity. The compositions and microstructures of the two powders with different magnetic properties were investigated. The results show that the superior powders contain less Zr and a relative more Fe, with integrated grains of about 20 similar to 60 nm in size and clear grain boundary without other phases. And the inferior powders contain more Zr and a relative lower Fe and metastable microstructures including the amorphous phases, the alpha-Fe and amorphous phases, and the un-integrated Nd2Fe14B phases of <= 10 nm in size. It is presumed that the ununiform magnetic properties are due to the elevated crystallization temperature induced by the more Zr content for the inferior powders.

The microstructure and corrosion behaviors of Zr-xFe-yCr alloys have been investigated in the superheated steam of 500℃/10.3 MPa. The results show that the composition of Zr-Fe-Cr alloy after vacuum melting, β quenching, vacuum covered hot and cold rolling, and vacuum annealing are α-Zr base and dispersed Zr(Cr, Fe)2 particles. A nodular corrosion takes place on the Zr-4 and Zr-0.2Fe-0.1Cr specimens, but uniform corrosions occur on the Zr-Fe-Cr alloys with appropriate Fe and Cr, in the 500℃ and 10.3 MPa superheated steam. The Zr-1.0Fe-0.6Cr specimens have the best corrosion resistance, and its corrosion resistance in the superheated steam is better than that of N18 and Zr-4 alloys. The alloy specimens with different contents of Fe and Cr are with quite different corrosion resistances, which indicates that the composition of zirconium alloys is the key factor to improve the corrosion resistance in 500℃/10.3 MPa.

The preparation technology and magnetic proper-ties of Nd9.5Fe77B6Co5Zr2.5 nanocomposite magnets were investigated by melt spinning and crystallization process. The nonuniform composition and grain size can be induced by nanocomposite magnet prepared by arc-melt-spinning process, which will decrease the magnetic properties. These can be avoided by modification of preparing process. Induction-melt-spinning furnace was designed successfully and applied to prepare nanocomposite magnets. The bonded magnet with B-r=0.736, H-cb=418 kA/m, H-cj=630 kA/m, M-r/M-s=0.7 and (BH)(max)=82.4 kJ/m(3) was prepared by this technology.

The preparation technology and magnetic proper-ties of Nd9.5Fe77B6Co5Zr2.5 nanocomposite magnets were investigated by melt spinning and crystallization process. The nonuniform composition and grain size can be induced by nanocomposite magnet prepared by arc-melt-spinning process, which will decrease the magnetic properties. These can be avoided by modification of preparing process. Induction-melt-spinning furnace was designed successfully and applied to prepare nanocomposite magnets. The bonded magnet with B-r=0.736, H-cb=418 kA/m, H-cj=630 kA/m, M-r/M-s=0.7 and (BH)(max)=82.4 kJ/m(3) was prepared by this technology.

Nanocrystalline Nd-10.1 Fe-(82.2x) Co5Zr2.7Bx (x=6.2, 6.5, 6.7, 7) permanent materials were prepared by melt-spun and subsequent heat treatment. The microstructures and magnetic properties of the alloys were investigated. The results show that optimal content of boron will improve the microstructures and magnetic properties of the alloys. At the wheel speed of 16 m.s(-1) and boron content of 6.7at%, the isotropic staturation remnaence ratio M-r/M-s is 0.758 and the optimal magnetic properties of the bonded magnets were obtained, B-r=0.72 T, (BH)(max) = 85.0 kJ.m(-3).

本文主要研究了不同含量的Zr-Nb-Cu合金的显微组织以及其在500℃，10.3 MPa 过热水蒸汽中耐腐蚀性能。结果表明Zr-Nb-Cu合金经过真空熔炼、β淬火、真空包覆热轧及冷轧和真空退火处理，得到的组织主要为α-Zr基体和弥散分布的第二相粒子。在500℃，10.3 MPa 过热水蒸汽中，含有适当Nb、Cu的Zr-Nb-Cu合金是均匀腐蚀。且其耐过热水蒸汽腐蚀能力优于N18和Zr-4合金。含Nb、Cu元素不同的实验锆合金由于成分不同，耐腐蚀性能也有明显的差别。Zr-1.0Nb-0.05Cu合金的耐蚀性最好。调整合金成分是改善锆合金在500℃，10.3 MPa 过热水蒸汽中的耐腐蚀性能的主要途径。