A novel method for enhancing the corrosion resistance of 316L stainless steel was investigated using nanosecond laser pulses in a high-relative humidity environment. The effects of parameters relative humidity level, overlap rate, and irradiation fluence on 316L stainless steel’s breakdown potential and impedance were studied. Increasing the overlap rate and the fluence initially increased the breakdown potential but later reduced it as both parameters increased further. A higher level of relative humidity significantly enhanced the breakdown potential and impedance. Significant positive breakdown potential above 1.0 V (Ag/AgCl) with good repeatability was achieved at the optimal laser irradiation parameters under the humidity level of 95

To texplore the feasibility of the nonlinear ultrasonic method in the aging microstructure evolution application of directionally solidified nickel-based superalloy, DZ411 directionally solidified nickel-based superalloy is studied. The microstructure observation, gamma' phase quantitative characterization, nonlinear ultrasonic detection, and lattice mismatch analysis of DZ411 alloy under different aging conditions are carried out by using nonlinear ultrasonic detection technology, combined with SEM and XRD. The correlation between nonlinear ultrasonic coefficient and quantitative parameters of microstructure evolution is discussed. The results show that with the extension of aging time, the gamma' phase size increases, the gamma' phase changes from cubic to spherical, the cubic degree decreases, the particle density decreases, and the normalized ultrasonic nonlinear coefficient increases exponentially. The nonlinear ultrasonic coefficient is positively correlated with the lattice mismatch, and the gamma' phase equivalent diameter, and negatively correlated with the gamma' phase area fraction. The analysis shows that the above phenomenon is attributed to the full diffusion of alloying elements and the redistribution of solute atoms at the two-phase interface during the aging process, increasing the gamma' phase size and the lattice strain at the two phase intorface, enhancing the interference of the local stress-strain field on the propagation characteristics of the ultrasonic wave and aggravating the distortion of the ultrasonic wave at the two-phase interface, thus promoting the generation of harmonic components and the enhancement of nonlinear effects.

Millimeter-sized ZTA (zirconia toughened alumina) particles + WC (tungsten carbide) particles reinforced hypereutectic high chromium cast iron (H-HCCI) composites were prepared by liquid phase sintering. The volume fraction, stacking method and sintering process of the reinforced particles in the composites were designed. The interfacial bonding mechanism between the reinforcements and the matrix in the composites was systematically discussed. The results show that when the sintering temperature is 1380 °C, the volume percentage of ZTA particles, WC particles and H-HCCI is set to 10, 30 and 60

Glass direct current product USES the uA level, LED chip light‐emitting efficiency under different temperature differences. Because of the glass substrate, high thermal conductivity, glass and metal bracket assembled light board, due to the contact position and not contact position Z to thermal resistance difference is bigger, results in a larger temperature difference in the surface, lead to white picture, stimulation and phenomenon of tic‐tac‐toe grid. Analyze the lamp plate heat source, according to the thermal distribution of different location, by adopting insulation tape, multilayer graphite flake scheme improve lamp plate to the heat conduction ability, X/Y for COF package IC and light insulating board contact with the aluminum frame position, improve the mold inside lamp panel heat distribution. Test: by improving measures after the light in the same drive power module can be glass straight under in‐plane horizontal arrows temperature reduced from 2.5 ℃ to 1.4 ℃, the improved white showing effect.

Converting Bi 2 S 3 into an efficient PHER catalyst by defect engineering to form solid solutions with the incorporation of Ce and O into Bi 2 S 3 for bimetal–chalcogen (Bi,Ce) 2 (O,S) 3− x catalysts.

为探索白光干涉仪在测量矩形台阶时的蝠翼效应误差,建立白光干涉虚拟测量模型.在模型中,考虑白光光源带宽和干涉物镜数值孔径以及圆孔衍射模型的影响,分析蝠翼效应与真实台阶高度、光源中心波长之间的关系.模拟结果表明当台阶高度差是λ0/4的奇数倍时会出现蝠翼效应,且越接近λ0/4的奇数倍,蝠翼效应越显著.关于对蝠翼误差的补偿,分别采用中值滤波和均值滤波两种方式对含有蝠翼效应的测量结果进行修正,并利用台阶高度、台阶与轮廓中线围成的面积两种评价参数对比补偿效果,结果表明中值滤波的修正结果优于均值滤波.

This study examined the mechanical properties, springback behavior from three-point bending loading–unloading tests and biocompatibility from human osteoblast cell adhesion and proliferation experiments in Ti-15Mo alloy with different microstructures. The springback ratio increased after the appearance of deformation microstructures including {332} < 113 > twins and dislocations, due to the increased bending strength and unchanged Young’s modulus. By contrast, the change in springback ratio was dependent on the competing effect of the simultaneous increase in bending strength and Young’s modulus after phase transformation, namely, the isothermal ω-phase formation. Good cell adhesion and proliferation were observed on the alloy surface, and they were not significantly affected by the deformation twins, dislocations and isothermal ω-phase. The diversity of deformation and phase transformation microstructures made it possible to control the springback behavior effectively while keeping the biocompatibility of the alloy as an implant rod used for spinal fixation devices.

利用COMSOL有限元模拟软件构建非线性表面波检测奥氏体不锈钢应力腐蚀微裂纹的模型,采用顺序耦合与直接耦合两种方式,分别实现应力场与声场的耦合.COMSOL软件在创建非线性表面波检测应力腐蚀微裂纹的模拟领域有很强的可行性与优越性,很大程度地简化了建模步骤,缩短了模拟运算时间.利用最优模型进一步讨论应力的大小以及微裂纹尺寸对非线性表面波传播特性的影响,并结合试验进行验证.结果表明:当微裂纹尺寸固定时,随着微裂纹边界处应力的增加,非线性响应降低;在恒应力作用下,非线性系数与微裂纹的深度呈正相关,与微裂纹宽度呈负相关;试验结果与模拟结果具有良好的一致性.

笔者采用液相烧结法制备出氧化铝颗粒增强过共晶高铬铸铁复合材料,通过扫描电镜,XRD检测,EBSD检测和摩擦磨损实验等对其结构与性能进行了研究.发现氧化铝颗粒均匀分布于基体材料中,并与基体材料形成了明显的润湿界面,复合材料具有良好的耐磨性.工业应用实验显示,在水泥生料立磨上,采用氧化铝颗粒增强过共晶高铬铸铁复合材料制备的耐磨辊套的使用寿命可以达到原高铬铸铁辊套寿命的2倍以上.

The combined effects of W, Mn and Mo additions on the microstructure and properties of a hypereutectic high chromium cast iron (HCCI) were studied. The results indicated that W was distributed uniformly in the matrix and carbides. The W and Mo addition promoted the formation of M2C and M6C carbides. When 13 wt.% Mn was added to the samples, the solubility of Mn in the matrix increased the stability of the austenite phase and improved the toughness of the materials. Moreover, Mn and Cr form the M7C3 carbides in hypereutectic HCCI. A large number of (Fe, Mn)3C carbides were produced in the matrix during the later stage of solidification, which significantly improved the wear resistance of the matrix. When the amount of W, Mn and Mo added was 6 wt.%, 15 wt.% and 4.2 wt.%, respectively, the HCCI exhibited the best performance herein. The addition of 6 wt.% W led to an increase in the average hardness of the samples and the microhardness of carbides of up to 57.5 HRC and 1680 HV, respectively. Similarly, it is worth mentioning that the impact toughness of the 6% W sample reached 6.35 J/cm2, and the mass loss of the Cr16 and 0% W samples was 1.43 and 1.23 times that of the 6% W sample, respectively. The wear resistance of the 6% W sample showed no significant change before and after heat treatment. The combination of W, Mn and Mo simultaneously improved the wear resistance and impact toughness of the hypereutectic HCCI.

Gas nitriding and high-energy ball milling were adopt to prepare iron nitrides samples. The iron nitrides samples with different nitrogen contents and different magnetic properties were obtained through mixing with different ingredients with high-energy ball milling process. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA). The iron nitrides samples were nanostructured and contained lots of interfaces, boundaries and defects inside the particles. The electromagnetic wave reflection loss (RL) value was simulated according to transmission line theory by using the samples' electromagnetic parameters. The sample with a saturation magnetization of 173.3 emu.g(-1) had the best RL value, which reached -63.31 dB at 17.93 GHz with a thickness of 1.77 mm. The samples with Ms value greater than 90.9 emu.g(-1) could effectively absorb electromagnetic waves in the Ku band. The absorption performance decreased with the decreasing Ms value. The nanostructure obtained by high-energy ball milling was discussed to be beneficial for improving the permittivity and the permeability of the iron nitrides samples in the Ku band. The electromagnetic wave absorption mechanisms were also analyzed. In addition, this study offers a reference for industrially producing electromagnetic wave absorbing materials with low cost.

： In order to explore the method of detecting the early stress corrosion damage of austenitic stainless steel by nonlinear surface wave, the reconstruction method is used to realize the coupling between stress field and ultrasonic field based on the elastic-plastic deformation constitutive relation by means of ANSYS and ABAQUS finite element numerical simulation software. Furthermore, the influence of micro-crack width and depth, stress direction (tension/compressive) and magnitude on the propagation characteristics of nonlinear ultrasonic surface wave are discussed. The results show that under constant loading, the width of micro-crack is negatively correlated with the nonlinear coefficient, while the depth is positively correlated with the nonlinear coefficient. The micro-crack is widen under the tensile stress, which not only reduces the transmitted surface wave energy, but also weakens the flapping and sliding effects caused by periodic vibration of the interface, so as to inhibit the generation of higher harmonics. Moreover, the critical width of micro-crack decreases with the increase of tensile stress. Compressive stress does the opposite. Therefore, the study on the interaction between the nonlinear surface wave and the micro-crack under constant stress has important engineering application value for the detection of early stress corrosion damage.

Different volume fraction ZTA particles reinforced high chromium cast iron (HCCI) matrix composites were fabricated by liquid phase sintering (LPS) in vacuum of 0.1 atmospheric pressure. The influence of manganese on the microstructure, phase constituents and mechanical properties of the ZTA particles reinforced HCCI composites was investigated by means of SEM, XRD, and nanoindentation tests. The results demonstrated that the interfacial layer with a thickness of 25-35 mu m was formed between ZTA particles and HCCI matrix, combined the effects of manganese additions. The elements in the interfaces layer are mainly Mn, Si, Zr and Al with a small amount of Fe. New phases formed by MnO acting on the surface of ZTA particles and the interfaces were MnO2 center dot Al2O3, Mn2SiO4 and MnFe2O4. However, in the interfaces layer near the matrix, MnO was reduced by C to form Mn and Mn3C and dissolved in HCCI matrix. The hardness and modulus of the interfacial layer were 20.25 GPa and 294.7 GPa, respectively. The wear mass losses of Cr20 sample is about 4.7 times higher than that of 40 vol% ZTA particles reinforced iron matrix composites.

The nitriding diffusion layer has been considered wearing excessively during diamond turning due to its low nitrogen content in previous research. In this study, by increasing the gas flow rate during the cooling process, an extra needle-precipitates free phase sublayer with a thickness of 25 μm was formed beneath the compound layer, along with the traditional diffusion layer. The microstructure was analyzed and diamond turning test was carried out on each sublayer. After diamond turning all sublayers, no significant wear was observed on the diamond tool. The α-Fe(N) phase with supersaturated nitrogen atoms was found that it can inhibit the wear of the diamond tool. The needle-free precipitates phase sublayer had the lowest surface roughness value after diamond cutting, which was 6.10 nm.

WC particle/HCCI composites were prepared using liquid-phase sintering technology. In this study, millimeter WC particles were used to ensure that minimal WC particle performance was compromised during the preparation process. Moreover, with the aim of controlling the evolution of microstructures and secondary carbide precipitation in the matrix, different heat treatment methods were adopted in the manufacturing process. The microstructures of the composites were investigated via SEM, XRD, EPMA and TEM. The results showed that perfect metallurgical bonding was formed between the LCS and the WC/HCCI composites, and the width of the diffusion layer was 120 to 129 mu m after heat treatment. A large number of secondary carbides precipitated in the matrix during heat treatment, and martensite formation occurred in the matrix during the subsequent cooling process, which effectively increased the microhardness of the matrix. The impact toughness of the LCS-toughened composites after heat treatment was 1.6 times that of the WC/HCCI composites, and the shear strength was 5 times that of the as-cast composites. The wear resistance of the composites under quenching at 950 degrees C and tempering at 220 degrees C was 5 times that of the as-cast composites.

Kinetics analysis of specific interactions of proteins is important for elucidating the molecular mechanism and the cellular process. In this work, we demonstrated a portable sensor based on fiber-optic (FO) surface plasmon resonance (SPR) sensing elements which can be used to detect the kinetics of protein-protein interaction. The sensor was built by FO-SPR sensing elements, an optical fiber, a red light-emitting diode (LED) and a detection platform based on smartphone. We set reference channel and control channel to compensate the fluctuations of the LED power, ambient temperature and refractive index (RI) of the buffer. Our sensor can monitor the interaction process in real-time and give valuable dynamic information. To verify its performance, the interactions between Ranse B/protein A and Con A/IgG were used as model systems. The sensor was examined by the recognitions of Con A and IgG on functionalized gold film, and the detection data was used to calculate the kinetic rate constant and binding constant of the reaction. The results demonstrate the superiority of our sensor in biomolecular recognition and kinetics analysis.

This paper provided a novel approach for evaluating phase stability and elastic properties in metastable Ti-Mo alloys with low Mo content by first-principles combined with cluster structure. In 54-atom body-centered-cubic supercell by substituting Ti atoms with 2-7 Mo atoms (7.1-23.0 wt% Mo), individual cluster structure of beta-phase was constructed by '-Mo-Ti-Mo-' cluster unit having the lowest cohesive energy. The distorted supercell was more stable than undistorted one at a low Mo content. With increasing Mo content, the density of state at Fermi level decreased, and bonding electron number increased, indicating beta-phase stability was gradually promoted. Tetragonal shear elastic constant (C ' = (C-11 - C-12)/2), shear modulus (G(111)) and anisotropy factor (A = C-44/C ') exhibited a fluctuation with Mo addition, while the change trend of A was opposite to C ' and G(111). Calculated Young's modulus exhibited similar changing trend to the C ', implying that the softening of C ' resulted in low Young's modulus of beta-phase. Measured Young's modulus exhibited significant difference from calculated one, which was mainly caused by formation of alpha ''-martensite and omega-phase. The values of C ', G(111) and A were considered to associate with not only elastic properties of beta-phase itself but also transition from beta-phase to alpha ''-martensite and/or omega-phase.

The nondestructive characterization of pitting corrosion of 304austenitic stainless sheets of steel is realized by nonlinear ultrasonic surface wave detection technique.The solid solution 304austenitic stainless sheets of steel are soaked in the FeCl3of 6.0％,10.0％and 14.0％for 6,12,and 18hrespectively. The surface morphology of the samples soaked is observed by OLS4000laser confocal microscope,and the three-dimensional morphology and size of the steady-state pitting holes are measured.The nonlinear coefficient of the ultrasonic surface wave is measured by RAM-5000.The normalized nonlinear coefficient is analyzed based on the morphology and dimensional change of the pits.The results show that the normalized nonlinear coefficient rises gradually with the increasing ultrasonic surface wave spreading distance.When the surface wave spreading distance is constant,the normalized nonlinear coefficient is significantly increased with the increase of soaking time and the mass fraction of the solution.It is concluded that the stress-strain nonlinear effect resulted from the interaction of ultrasonic wave and discontinuous interface around pits tends to be remarkable with the increasingly serious pitting damage.

In the present study, a high chromium cast iron (HCCI) alloyed with Mo (16 wt.% Cr-6 wt.% Mo-2.4 wt.% C) with excellent wear resistance was bonded to a low carbon steel (LCS) by surface liquid-phase sintering. The bimetal was also subjected to a quenching + tempering treatment. The diffusion behavior of the atoms between the HCCI and LCS was analyzed. The bonding strength of the bimetal was investigated before and after heat treatment. The results show that the bimetal had a good bonding quality due to the uphill diffusion of C atoms. A diffusion zone with a width of approximately 37 μm and a troostite structure formed on the HCCI side by the interface. With different bonding times, there was no obvious change in the width of the diffusion zone. The shear strength of the bimetal at all holding times was reduced from a high level after heat treatment and decreased with increasing tempering temperature. The impact toughness of the bimetal substantially increased compared with that of the HCCI. After a quenching treatment, the impact toughness of the bimetal decreased, and the microhardness of the diffusion zone improved. As the tempering temperature increased, the microhardness and impact toughness decreased and increased, respectively.

Hot corrosion behaviors of CoCrFeNiTi0.5 high entropy alloy pre-coated various mixture salt in air at 750°C were investigated respectively by using weight change kinetics, X-ray analyses, SEM equipped with EDS and EPMA. The results indicate that CoCrFeNiT0.5 alloy exhibits relatively high corrosion resistance in Na2SO4-25%K2SO4 molten salts. The cross-section is divided into three parts: the oxide scale composed of various oxides, the corrosion affected zones with some micro-pores as well as minor of sulfides and the matrix. The addition of NaCl to Na2SO4 destroys seriously the integrity and compactness of the oxide scale and induces the formation of more micro-pores as well as sulfides in the corrosion affected zone, which accelerates the propagation of hot corrosion. As a result, the alloy suffers from more severe corrosion in Na2SO4-25% NaCl than in Na2SO4-25%K2SO4. Hot corrosion of the alloy in Na2SO4-25%K2SO4 is explained based on the oxidation and the basic fluxing of Cr2O3 in molten Na2SO4. However, hot corrosion process in Na2SO4-25% NaCl is dominated by the interaction of oxidation and chlorination. In addition, the internal sulfidation of Fe and Ni also contributes to hot corrosion of the alloy in both Na2SO4-25%K2SO4 and Na2SO4-25% NaCl mixture salt.