ISSN 1005-3093
CN 21-1328/TG
Started in 1987

About the Journal

  Current Issue
    , Volume 33 Issue 9 Previous Issue    Next Issue
    For Selected: View Abstracts
    ARTICLES
    Relationship Between Mechanical Behavior and Microstructure for an Ultra-high Strength Maraging Steel
    FENG Jiawei,NIU Mengchao,WANG Wei,SHAN Yiyin,YANG Ke
    Chinese Journal of Materials Research, 2019, 33 (9): 641-649.  DOI: 10.11901/1005.3093.2018.707
    Abstract   HTML   PDF (17102KB) ( 545 )

    Precipitate evolution during aging process as well as its effect on mechanical properties of a 2.4 GPa grade ultra-high strength maraging steel was investigated by means of high resolution transmission electron microscope (HRTEM) and atom probe tomography (APT). It was found that at the initial stage of aging Ni and Ti atoms segregated rapidly and Ni-Ti clusters formed in the matrix. At the peak-aging time the Ni-Ti clusters transformed into Ni3Ti, and the Mo-rich phase appeared at the Ni3Ti/matrix interface. With extension of the aging time Ni3Ti phase started to coarsen and the Mo-rich phase transformed into Ni3Mo. Mechanical property tests show that the ultimate tensile strength increased firstly and then started to decrease after peak-aging time. A mutually exclusive relation between the ultimate tensile strength and fracture toughness was found, especially, when the aging time was 4 h the ultimate tensile strength reached to the maximum value of 2560 MPa, however the fracture toughness decreased down to the minimum value of 20 MPa·m1/2. Finally, the effect of the morphology of the precipitates on both the strength and fracture toughness is discussed based on the results of the precipitates evolution during aging process.

    Figures and Tables | References | Related Articles | Metrics
    Microstructure Evolution and Mechanical Properties of Rapid Solidified AlCoCrFeNi2.1 Eutectic High Entropy Alloy
    CAO Leigang,ZHU Lin,ZHANG Leilei,WANG Hui,CUI Yan,YANG Yue,LIU Fengbin
    Chinese Journal of Materials Research, 2019, 33 (9): 650-658.  DOI: 10.11901/1005.3093.2019.069
    Abstract   HTML   PDF (7636KB) ( 530 )

    Rods with different diameters and ribbons of the multi-component eutectic high-entropy alloy AlCoCrFeNi2.1 were prepared by vacuum rapid solidification facility. The effect of cooling rate on microstructure and mechanical properties of the alloy was investigated. The results show that all of the alloys consist of FCC and B2 phases. Alloy rods of different diameters present a typical eutectic structure, with the presence of the cellular microstructure at certain sites of axial surface regions. The decrease of the diameter raises the cooling rate of the casting rod, resulting in the decrease of lamellar spacing (λ) of the regular eutectic structure and the increase of yield strength. As the diameter decreases from 8 mm to 2 mm, the values of λ decrease from 530.4 to 357.0 μm in the axial surface regions and from 712.0 μm to 474.0 μm in the axial center regions, resulting in the increase of the yield strength from 690 MPa to 877 MPa. As far as the microstructure morphology of the alloy ribbons is concerned, it can be concluded that the microstructure of the alloy may evolves in the following sequence, namely, regular and irregular eutectic structure, cellular structure and dendrite structure as the cooling rate is increased.

    Figures and Tables | References | Related Articles | Metrics
    Characterisation of Passive Film on HRB400 Steel Rebar in Curing Stage of Concrete
    SHANG Baihui,MA Yuantai,MENG Meijiang,LI Ying
    Chinese Journal of Materials Research, 2019, 33 (9): 659-665.  DOI: 10.11901/1005.3093.2019.068
    Abstract   HTML   PDF (1680KB) ( 297 )

    The standard curing time of concrete is 28 days in order to guarantee the strength of the concrete. It is well known that a stable passive film can be formed on the surface of steel rebar in the alkaline pore fluid during the concrete curing stage, long before the steel rebar will be influenced by chloride ingress or concrete carbonation in the future. However, there is no consensus on the time conditions for the pre-passivation of the steel bars in the open literature. In this study, the growth process and characteristic evolution of the passive film formed on HRB400 steel rebar in a Ca(OH)2 saturated solution, which aims to simulate the medium in concrete pores during curing period, were studied by a series of electrochemical tests (open-circle potential (OCP), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curve (PDC)) and XPS. Results show that it will take 5 days to form a stable passive film on the surface of HRB400 steel rebar, and the passive film has a two-layered structure. In the initial stage of passivation, on the HRB400 steel surface a thin film mainly composed of Fe(II) products firstly formed, then on top of which, a film mainly composed of Fe(III) products would further form.

    Figures and Tables | References | Related Articles | Metrics
    Effect of PEG6000 on Electroless Copper in Dual-Ligands System
    LU Jianhong, DENG Xiaomei, YAN Jianhui, TU Jiguo, WANG Mingyong, JIAO Shuqiang
    Chinese Journal of Materials Research, 2019, 33 (9): 666-672.  DOI: 10.11901/1005.3093.2019.060
    Abstract   HTML   PDF (4493KB) ( 328 )

    The effect of surfactant polyethylene glycol (PEG) 6000 on the electroless copper plating process in a bath of dual-ligands ethylenediamine tetraacetic acid (EDTA)/tetrahydroxypropyl ethylenediamine (THPED) was investigated by electrochemical method. Mixed potential-time curves indicate that the overall process can be divided into three districts: induction, transitional and stable region. PEG6000 can slowdown the negative shifting of electrode potential, which related to the retardation of the adsorption of charged ions resulted from the surfactant adsorption on the copper electrode. Linear sweep voltammetry measurements show that cathodic reduction reaction is the controlling step for the plating process; PEG6000 could retard cathodic polarization, therewith, the peak value of cathodic reduction current decreased about 40%, so PEG6000 linearly reduced deposit speed. The copper layers prepared from the bath with PEG6000 are product of high-purity with a surface morphology of uniformly distributed fine particles, moreover, the addition of PEG6000 favored the formation of copper layer with (220) preferred orientation with refined grains of average size 50.0 nm, in comparison with 77.7 nm that from the bath without PEG6000 addition.

    Figures and Tables | References | Related Articles | Metrics
    Effect of Minor Sc on Microstructure and Properties of Al-Zn-Mg Alloy Weld Joint
    LI Zhaoming,JIANG Haichang,YAN Desheng,ZHANG Hongliang,RONG Lijian,WU Fei
    Chinese Journal of Materials Research, 2019, 33 (9): 673-682.  DOI: 10.11901/1005.3093.2019.064
    Abstract   HTML   PDF (27080KB) ( 217 )

    The microstructures, tensile properties and stress corrosion cracking resistance of tungsten inert gas weld joints of Al-Zn-Mg alloy and Al-Zn-Mg alloy with 0.06% (mass fraction) Sc were comparatively investigated by means of optical microscope, scanning electron microscope, transmission electron microscopy, electronic universal testing machine and slow strain rate test. The results show that recrystallization with abnormal grain growth occurred in heat affected zone near the fusion line of the traditional Al-Zn-Mg alloy, while the excellent thermal stability of secondary Al3(Sc, Zr, Ti) phase existed in the Al-Zn-Mg alloy with 0.06% Sc, which could hinder the grain boundary migration during the welding process, thereby inhibit the nucleation and growth of recrystallized grains and then refine the grain size in the matrix near the fusion line. At the same time, the strength of the weld joint for Al-Zn-Mg alloy with 0.06% Sc is obviously higher than that for Al-Zn-Mg alloy, which is mainly related to the grain-boundary strengthening and dispersion strengthening caused by secondary Al3(Sc, Zr, Ti) phase.

    Figures and Tables | References | Related Articles | Metrics
    Modifying Effect of Ce Addition on Primary Mg2Si Phase in Mg-5Si Alloy
    FAN Jinping,WANG Hao,WU Gailin,JIANG Yifeng,WANG Hao,LIU Chunlian
    Chinese Journal of Materials Research, 2019, 33 (9): 683-690.  DOI: 10.11901/1005.3093.2019.080
    Abstract   HTML   PDF (13365KB) ( 354 )

    The modifying effect of Ce addition on primary Mg2Si phase in Mg-5Si alloy was investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), optical microscopy (OM), ICP spectrometry and X-ray diffraction (XRD). The results show that the morphology of the primary Mg2Si phase changed from coarse dendritic shape to polygonal shape with the addition of various amount of Ce. The eutectic Mg2Si phase changed from Chinese-characters shape to fine fiber shape or dot shape. The optimum modification effect was obtained when the amount of Ce addition was 1.2%. The size of the primary Mg2Si decreased from 48 μm to 9 μm or less. Whilst, short rod-shaped Mg-Si-Ce compounds were found in the alloy with 1.6% Ce. Ce promotes the nucleation of Mg2Si, and inhibits its anisotropic growth.

    Figures and Tables | References | Related Articles | Metrics
    Preparation and Properties of Hybrid Proton Exchange Membranes of SPES-C/MIL-53(Al)-SO3H
    HAN Guanglu,CHEN Zhe,CAI Lifang,TIAN Junfeng,ZHANG Xuebo,MA Huanhuan
    Chinese Journal of Materials Research, 2019, 33 (9): 691-698.  DOI: 10.11901/1005.3093.2019.140
    Abstract   HTML   PDF (5764KB) ( 357 )

    MIL-53(Al) was synthesized through hydrothermal synthesis, then sulfonic groups were introduced into MIL-53(Al) cages by sulfonation reaction to obtain MIL-53(Al)-SO3H with proton conduction property. The post-synthetic MIL-53(Al)-SO3H was incorporated into sulfonated polyarylethersulfone with cardo (SPES-C) polymer matrix to form hybrid PEMs. SEM results show that MIL-53(Al)-SO3H dispersed uniformly in SPES-C phase and no obvious interfacial defects in membranes could be observed. The TGA analysis confirmed that the membranes of PEMs have excellent thermal stability. The water uptake was enhanced with embedding MIL-53(Al)-SO3H and it presented positive correlation with composition. The incorporation of MIL-53(Al)-SO3H also inhibited the swelling ratio, indicating the excellent dimensional stability of the as-prepared hybrid PEMs. The hybrid PEMs also showed encouraging proton conductivity. The proton conductivity of the hybrid PEMs with incorporation amount of 5% (in mass fraction) MIL-53(Al)-SO3H reached to 0.15 S·cm-1, which was 32.5% higher than that of the pristine SPES-C membrane, and exceeded that of the ordinary commercial Nafion membrane (0.134 S·cm-1).

    Figures and Tables | References | Related Articles | Metrics
    Pyrolysis Kinetics of Glass Fiber/Epoxy Foam Sandwich Panel
    CHEN Songhua,XU Yanying,WANG Zhi,WANG Jing
    Chinese Journal of Materials Research, 2019, 33 (9): 699-704.  DOI: 10.11901/1005.3093.2019.192
    Abstract   HTML   PDF (1772KB) ( 193 )

    The thermal decomposition characteristics of glass fiber/epoxy foam sandwich panels was studied via DTG-60(AH) thermogravimetric analyzer by different heating rates and in three atmospheres with different oxygen contents. The results show that the pyrolysis reaction of glass fiber/epoxy foam sandwich panels in air can be differentiated into three stages. As the heating rate increases, the initial reaction temperature, the termination reaction temperature and the maximum mass loss rate temperature of the pyrolysis reaction shifted to the high temperature. The decrease of oxygen content in atmospheres has a greater impact on the third stage of thermal decomposition. The pyrolysis kinetics were analyzed by the Flynn-Wall-Ozawa method and the Starink method to obtain the apparent activation energy.

    Figures and Tables | References | Related Articles | Metrics
    Effect of MgCl2 Deposite on Simulated Atmospheric Corrosion of Zn via Wet-dry Altertnating Corrosion Test
    YIN Qi,LIU Miaoran,LIU Yuwei,PAN Chen,WANG Zhenyao
    Chinese Journal of Materials Research, 2019, 33 (9): 705-712.  DOI: 10.11901/1005.3093.2019.188
    Abstract   HTML   PDF (8248KB) ( 205 )

    The effect of MgCl2- and NaCl-deposit on simulated atmospheric corrosion of Zn was comparatively investigated via wet-dry alternating corrosion test, as well as mass loss, X-ray diffraction (XRD), scanning electron microscope equipped with energy dispersive spectrometer (SEM-EDS). The results show that the corrosion rate of Zn was significantly inhibited by the deposition of MgCl2; the corrosion products formed on Zn plate with NaCl deposit were Zn5(OH)8Cl2·H2O、Zn4CO3(OH)6·H2O and Zn(OH)2, while was only Zn5(OH)8Cl2·H2O for Zn plate with MgCl2 deposit. It was proposed that the corrosion may be caused by the decrease of pH, which was induced by the precipitation of Mg2+ ions and OH- ions, in the cathodic sites.

    Figures and Tables | References | Related Articles | Metrics
    Influence of High Temperature Water Vapor on Characteristics of CO2 Electrochemical Sensor
    WANG Guangwei,CHEN Hongzhen,LI Youfeng,XIE Bo,JIANG Zhongyuan
    Chinese Journal of Materials Research, 2019, 33 (9): 713-720.  DOI: 10.11901/1005.3093.2018.711
    Abstract   HTML   PDF (4622KB) ( 226 )

    Carbon dioxide electrochemical sensor was prepared with Li and Ba co-doped oxycarbonate as auxiliary sensing electrode and YSZ as electrolyte, then the influence of high temperature water vapor on the performance of the sensor was investigated. The results show that the potentiometric sensor respond correctly and rapidly to the change of CO2 concentration (271~576802 μL/L) after pretreatment in water vapor (300℃) for 24~120 h. The number of transfer electrons of the electrode reactions were approximately 2. Low oxygen dependency was found for the sensors, whether they were pretreated or not in water vapor for 120 h, all responded rapidly and accordingly for different oxygen content. The sensor worked not only in water vapor for relatively long term, but also after the constantly water vapor treatment to some extent.

    Figures and Tables | References | Related Articles | Metrics