Co-reporter:Long Zhang, Zhengwang Zhu, Huameng Fu, Hong Li, Haifeng Zhang
Materials Science and Engineering: A 2017 Volume 689(Volume 689) pp:
Publication Date(Web):24 March 2017
DOI:10.1016/j.msea.2017.02.070
Ti/Zr-based bulk metallic glass composites (BMGCs) containing an in-situ formed β phase (β-type BMGCs) normally show a poor work-hardening capability or even work-softening during plastic deformation. The limited work-hardening capability of the β phase by the entanglement of dislocations cannot totally compensate the shear softening of the glassy matrix. In this work, a strategy is proposed to destabilize the β phase, and the BMGC containing a metastable β phase (metastable β-type BMGC) shows improved plasticity and work-hardening capability due to the deformation-induced phase transformation from β-Ti to α″-Ti. The underlying principle for destabilizing β phases in BMGCs by adjusting the overall compositions and the structural origins for the improved plasticity and work-hardening capability of metastable β-type BMGCs are discussed. These findings shed light on developing metastable β-type BMGCs with excellent mechanical properties.
Co-reporter:L. Zhang, W.Q. Li, Z.W. Zhu, H.M. Fu, ... H.F. Zhang
Journal of Materials Science & Technology 2017 Volume 33, Issue 7(Volume 33, Issue 7) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/j.jmst.2016.03.025
In order to obtain a glassy matrix during quenching, Be is often selected as a constituent of the compositions of Ti/Zr-based bulk metallic glass composites (BMGCs). The in situ formed β phase in Be-bearing BMGCs was reported to be Be-free. However, a thorough investigation of the distribution of Be in BMGCs is still missing to date. In this work, the distribution of Be in a Ti47.5Zr33Cu5.8Co3Be12.5 (at.%) BMGC was studied by the secondary ion mass spectrometry (SIMS) and the electron energy loss spectroscopy (EELS). It is found that Be almost totally dissolves in the glassy matrix, but a very weak intensity of Be in β phase is still detectable by SIMS, and the content of Be in β-Ti is estimated to be about 0.3 at.%. Based on the recently established two-phase quasi-equilibrium of BMGCs, the distinct solubility of Be in the glassy matrix and in β-Ti has been explained.
Co-reporter:L. Zhang, S. Chen, H.M. Fu, H. Li, Z.W. Zhu, H.W. Zhang, Z.K. Li, A.M. Wang, H.F. Zhang
Materials & Design 2017 Volume 133(Volume 133) pp:
Publication Date(Web):5 November 2017
DOI:10.1016/j.matdes.2017.07.062
•Precipitation of ω-Ti was revealed to account for the sub-Tg exothermic reaction of metastable β-type BMGCs.•Precipitation of isothermal ω-Ti significantly increases the modulus and hardness of the crystalline phase in β-type BMGCs.•Precipitation of isothermal ω-Ti does not alter the morphologies of the crystalline phase in β-type BMGCs.•Smaller modulus and lower hardness of the crystalline phase were substantiated to cause a lager plasticity of BMGCs.It is challenging to tailor the mechanical properties of in-situ formed β phases in Ti/Zr-based bulk metallic glass composites (β-type BMGCs) without changing the morphologies of the β phases. Recently, BMGCs containing metastable β-Ti/Zr phases (metastable β-type BMGCs) exhibit an exothermic reaction below the glass transition temperature (sub-Tg) of the glassy matrices during heating, however, the corresponding structural origin remains unclear. In this work, the precipitation of ω phase inside β phase was revealed to account for the sub-Tg exothermic event of the metastable Ti45.7Zr33Cu5.8Co3Be12.5 BMGC. The sub-Tg annealing of metastable β-type BMGCs causes the precipitation of nanometer-sized isothermal ω phase, which leads to a large increase in the modulus and hardness of the crystalline phase. This finding provides a novel route to tailor the modulus and hardness of the crystalline phases in BMGCs without changing their morphologies, including volume fractions, sizes, and distributions. On this basis, the influence of the modulus and hardness of the crystalline phase on mechanical properties of BMGCs was exclusively investigated. Our experimental results together with finite-element simulations proved that lower modulus and hardness of the crystalline phase benefit a larger plasticity of BMGCs.Download high-res image (378KB)Download full-size image
Co-reporter:Xindong Qin, Zhengkun Li, Zhengwang Zhu, Huameng Fu, ... Haifeng Zhang
Journal of Materials Science & Technology 2017 Volume 33, Issue 10(Volume 33, Issue 10) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.jmst.2017.01.024
The mechanism and kinetics of acid orange II (AOII) treated by aged gas-atomized Fe-Si-B metallic glass (MG) powders were investigated in this study. The decolorization reaction is shown to obey the pseudo-first-order kinetic model, and the treatment processes could be divided into two stages: a slow step followed by a rapid one. This observation is in accordance with the following results, the azo dye is simply adsorbed onto the Fe-based MG powders in the initial stage, because the oxide layer coated on the powder surface depresses the degradation reaction by covering the activity sites, and then the degradation occurs with the desquamation of the powders. The AOII could be degraded with a rapid reaction rate when the Fe-based MG powders are applied to the treatment process again, because of the consumption of the oxide layer and the unchanged core of the Fe-based MGs. These findings will promote the practical application of MGs in degrading azo dyes.
Co-reporter:L. Zhang, S. Pauly, Z.W. Zhu, T. Gemming, H.M. Fu, J. Eckert, H.F. Zhang
Intermetallics 2016 Volume 73() pp:5-11
Publication Date(Web):June 2016
DOI:10.1016/j.intermet.2016.02.002
•TEM specimens prepared by ion milling show regular micrometer-sized patterns.•Compositions are changing within these patterns.•Certain regions (compositions) show preferential partial crystallization.•TEM specimens prepared by electrolytic thinning show a uniform microstructure.•A mechanism for ion milling-induced preferential crystallization is proposed.The Ti36.2Zr30.3Cu8.3Fe4Be21.2 (at.%) bulk metallic glass (BMG) exhibits a regular micrometer-sized pattern in the transmission electron microscope (TEM) after ion milling. Quantitative energy-dispersive X-ray spectroscopy (EDX) results show that the compositions in the bright and dark regions are distinctly different, and the compositions gradually change with the contrast of the pattern. In the intermediate regions (with grey contrast) preferential crystallization is observed and this confirms that microscale heterogeneities exist in the ion-milled TEM specimens. On the contrary, the specimens prepared by focused ion beam and by electrolytic thinning show featureless microstructures in the TEM. Moreover, EDX results and the secondary ion mass spectroscopy show that the constituent elements are homogeneously distributed. An ion milling-induced compositional fluctuation mechanism is proposed, and the partial devitrification can be explained based on this mechanism. The present findings may lead to a deeper understanding of the occurrence of micrometer-sized heterogeneities in BMGs induced by ion milling.
Co-reporter:L. Zhang, M.Q. Tang, Z.W. Zhu, H.M. Fu, H.W. Zhang, A.M. Wang, H. Li, H.F. Zhang, Z.Q. Hu
Journal of Alloys and Compounds 2015 Volume 638() pp:349-355
Publication Date(Web):25 July 2015
DOI:10.1016/j.jallcom.2015.03.120
•Seven BMGs with dc over 20 mm are developed in the Ti–Zr–Cu–Fe–Be system.•No. 6 and No. 7 alloys could directly solidify into 150 g amorphous ingots.•The dc of No. 7 alloy is over 50 mm by the simple cooper mold casting method.•These BMGs show large compressive plasticity and are intrinsically plastic.•These Ti–Zr–Cu–Fe–Be BMGs show work hardening-like behavior.We report seven TiZr-based bulk metallic glasses (BMGs) developed in the Ti–Zr–Cu–Fe–Be alloy system with critical sizes over 20 mm for glass formation. Especially, the melts with compositions of Ti31.9Zr33.4Cu8.7Fe4Be22 (at.%, No. 6 alloy) and Ti32.8Zr30.2Cu9Fe5.3Be22.7 (No. 7 alloy) can directly solidify into 150 g glassy ingots, and the No. 7 alloy could be cast into an amorphous rod with a diameter of 50 mm and a height of 75 mm by the simple copper mold casting method. Yield strength, maximum strength, the increase of true stress after yielding, and compressive plastic strain of No. 6 BMG are 1720 MPa, 2010 MPa, 165 MPa and 8%, respectively. Other BMGs show similar mechanical properties with compressive plastic strains more than 5%, concomitant work hardening-like behavior. A parameter named as angles of spherical compositional vectors (ASCVs) was proposed to quantitatively evaluate the discrepancy between two multiple-component compositions. These plastic BMGs with exceptional GFA in the Ti–Zr–Cu–Fe–Be alloy system have enriched the family of BMGs and may have scientific significance on developing advanced BMGs for practical applications.Graphical abstract
Co-reporter:Dechuan Yu, Xiaogang Shi, Huameng Fu, Yan Geng, Zhengwang Zhu, Yang Qi, Haifeng Zhang
Materials Letters 2015 Volume 157() pp:299-302
Publication Date(Web):15 October 2015
DOI:10.1016/j.matlet.2015.05.142
•A new method was proposed to quickly locate good glass formers in 3D space.•Glass formers were obtained by combining clusters and mixing entropy.•Several new Zr-based glass formers with high glass forming ability were quickly discoveredAimed at developing new Ni-free Zr-based bulk metallic glasses (BMGs), a series of Ni-free Zr–Al–Fe–Cu glass formers have been developed in this work. The compositions are designed by using a combination of clusters and mixing entropy. Glass formers in this system are considered to be a mixture of Zr–Al, Zr–Fe and Zr–Cu clusters. Their coefficients were obtained by the calculation of mixing entropy. Under the guidance of this method, a series of compositions with high glass forming ability (GFA) were developed. Among the glass formers, the alloy compositions of Zr60.32Cu22.56Fe9.95Al7.17 and Zr64.08Cu18.78Fe10.02Al7.12 possess the highest GFA. Glassy rods can be fabricated at these two compositions with critical diameter up to 5 mm, which is superior to that reported for the known Zr60Cu25Fe5Al10 BMG under the same condition.
Co-reporter:Jinbo Wu, Zhengwang Zhu, Hongwei Zhang, Huameng Fu, Hong Li, Aimin Wang, Haifeng Zhang, Zhuangqi Hu
Electrochimica Acta 2014 Volume 146() pp:322-327
Publication Date(Web):10 November 2014
DOI:10.1016/j.electacta.2014.09.075
Electrochemical performance of the as-prepared silicon based composite electrode for lithium ion battery can be enhanced by modifying the surface morphology of the Cu foil used as the anode current collector. Increasing the roughness of the Cu foil, contributes to the strong interface adhesion between the anode current collector and the silicon based active composite material slurry layer. The electrode with surface morphology modified Cu current collector delivers higher specific capacity and exhibits better rate capability than that with unmodified Cu current collector. It is also found that the cycle-life of the silicon based composite electrode has been significantly improved by using a surface morphology modified anode current collector. The enhanced cyclability is attributed to the good electrical contact integrality between the active materials and the anode current collector. The improved electrochemical performance indicates that optimizing the anode current collector system can be a valuable alternative for improving electrochemical properties of lithium ion rechargeable batteries.
Co-reporter:Bo Zhang, Huameng Fu, Zhengkun Li, Zhengwang Zhu, Haifeng Zhang, Zhuangqi Hu
Materials Science and Engineering: A 2014 619() pp: 165-170
Publication Date(Web):
DOI:10.1016/j.msea.2014.09.084
Co-reporter:H.M. Fu, N. Liu, A.M. Wang, H. Li, Z.W. Zhu, H.W. Zhang, H.F. Zhang, Z.Q. Hu
Materials & Design 2014 58() pp: 182-186
Publication Date(Web):
DOI:10.1016/j.matdes.2013.12.063
Co-reporter:P.F. Sha, Z.W. Zhu, H.M. Fu, H. Li, A.M. Wang, H.W. Zhang, H.F. Zhang, Z.Q. Hu
Materials Science and Engineering: A 2014 Volume 589() pp:182-188
Publication Date(Web):1 January 2014
DOI:10.1016/j.msea.2013.09.078
The effects of casting temperature on the microstructure and mechanical properties of an in-situ bulk metallic glass matrix composite (BMGMC) with a nominal composition of Ti45.7Zr33Ni3Cu5.8Be12.5 (at.%) are investigated through X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the uniaxial compression tests and a finite-volume-method (FVM) analysis. With different casting temperatures, the cooling rate and oxygen content are found to be responsible for the partial crystallization of the amorphous matrix and the variation of the morphology of the crystalline dendrites. Furthermore, the partial crystallization in the amorphous matrix of the BMGMC together with the variation of the morphology of dendrites are the possible reasons for the different tendency observed in strength and plastic deformation of the composite.
Co-reporter:Juan Mu, Zhengwang Zhu, Ru Su, Yandong Wang, Haifeng Zhang, Yang Ren
Acta Materialia 2013 Volume 61(Issue 13) pp:5008-5017
Publication Date(Web):August 2013
DOI:10.1016/j.actamat.2013.04.045
Abstract
The deformed-induced microstructure evolution and phase transformation behavior of Ti-based amorphous alloy composites (AACs) containing ductile dendrites in situ formed during solidification were investigated using ex situ transmission electron microscopy (TEM) and in situ high-energy X-ray diffraction (HE-XRD). In situ synchrotron-based HE-XRD experiments provide clear evidence on the deformation-induced phase transformation from β to α″ martensite initiated already in the linear elastic stage of the macroscopic stress–strain curve. Detailed analyses from the diffraction experiments show that the grains that were aligned with [0 0 1]β along the loading direction (LD) were then easily transformed into α″ martensite, whereas the martensitic variants oriented with [1 0 0]α″ along LD were preferentially formed under compression. The current study provides quantitative information about changes in various microstresses between the crystal phase and the amorphous matrix during deformation. Enhancement of the macroscopic plasticity of the AACs was mainly attributed to the strain relaxation in the β phase and to the formation of multiple shear bands in the amorphous matrix triggered by the deformation-induced phase transformation inside β, knowledge of which greatly deepens understanding of the complex micromechanical behaviors in advanced AACs.
Co-reporter:G.F. Ma, Z.K. Li, C.L. He, Z.W. Zhu, H.M. Fu, A.M. Wang, H. Li, H.F. Zhang, Z.Q. Hu
Journal of Alloys and Compounds 2013 Volume 549() pp:254-259
Publication Date(Web):5 February 2013
DOI:10.1016/j.jallcom.2012.09.066
The present work describes the interactions that occur between TiZr-based BMG and W substrate. The sessile drop method was used to study the wetting behavior and interfacial characteristics of molten Ti32.8Zr30.2Ni5.3Cu9Be22.5 alloy on W substrate in the temperature range of 973–1323 K in high vacuum. Good wettability with the final equilibrium contact angles of 53–23 was obtained. The interfacial reaction depended on the experimental temperature, namely, W2Zr granular phases particles appeared at the interface when the experimental temperature was 1273 K. The study was also focused on the spreading kinetics to determine the mechanisms controlling the rate of spreading. The spreading kinetics of molten Ti32.8Zr30.2Ni5.3Cu9Be22.5 alloy on W substrate consists of up to three regions according to the experimental temperature.Highlights► Interactions occur between molten Ti32.8Zr30.2Ni5.3Cu9Be22.5 alloy and W substrate. ► Good wettability was obtained. ► The interface reaction depended on the temperature of the test. ► The study was also focused on wetting kinetics to determine the mechanisms. ► According to the experimental temperature three regions were identified.
Co-reporter:L. Zhang, Z.W. Zhu, A.M. Wang, H. Li, H.M. Fu, H.W. Zhang, H.F. Zhang, Z.Q. Hu
Journal of Alloys and Compounds 2013 Volume 562() pp:205-210
Publication Date(Web):15 June 2013
DOI:10.1016/j.jallcom.2013.02.047
The limited glass forming ability (GFA) and deficient plasticity are two longstanding bottlenecks for the applications of bulk metallic glasses (BMGs) as structural materials. In this article, we report a TiZr-based BMG with nominal composition of Ti36.2Zr30.3Cu8.3Fe4Be21.2 (at.%) which possesses exceptional GFA and remarkable compressive plasticity simultaneously. The alloy ingot in weight of 150 g can be solidified into an amorphous state, indicating an exceptional GFA – the critical size for glass forming of the current BMG is estimated over 50 mm. The plasticity of about 8% was obtained from the as-cast 2-mm-diameter rod with an aspect ratio of 2, concomitant obvious work hardening effect. The present BMG possessing exceptional GFA and remarkable compressive plasticity simultaneously may have a scientific importance on developing BMGs for structural applications.Highlights► A TiZr-based BMG was developed in Ti–Zr–Cu–Fe–Be system for the first time. ► This BMG possesses an exceptional GFA and remarkable plasticity simultaneously. ► The critical size is over 30 mm by copper mold pour casting method. ► The plastic strain is as large as 8% concomitant an obvious work hardening effect. ► The compressive plasticity is the largest among those of BMGs with dC over 20 mm.
Co-reporter:Z.K. Li, G.F. Ma, H.M. Fu, P.F. Sha, B. Zhang, Z.W. Zhu, A.M. Wang, H. Li, H.W. Zhang, H.F. Zhang, Z.Q. Hu
Materials Letters 2013 Volume 98() pp:98-101
Publication Date(Web):1 May 2013
DOI:10.1016/j.matlet.2013.02.005
The wettability and spreading kinetics of Zr-based alloy melt on W substrate were evaluated using the modified sessile drop method under ultrahigh vacuum. The alloy melt wets the substrate well and the spreading kinetics indicates that drop spreading is mainly controlled by the viscous friction. The drop spreads rapidly and the spreading follows the hydrodynamic model and Jiang's empirical formula. The spreading of the drop shows little interaction with the precursor film, which is generated by diffusion. After the initial incubation period, the equilibrium contact angle stabilizes at about 29°, and the precursor film spreads linearly with the square root of time.Highlights► Drop spreading is mainly controlled by the viscous friction. ► The precursor film has little influence on the drop spreading. ► After the incubation period, the precursor film spreading is determined by diffusion.
Co-reporter:Bo Zhang, Huameng Fu, Pengfeng Sha, Zhengwang Zhu, Chuang Dong, Haifeng Zhang, Zhuangqi Hu
Materials Science and Engineering: A 2013 Volume 566() pp:16-21
Publication Date(Web):20 March 2013
DOI:10.1016/j.msea.2012.12.080
The compressive deformation behaviors of Zr-based metallic glass composites containing different tungsten fiber orientations were investigated. The angles (θf) between tungsten fiber orientation and loading axial direction are 0°, 15°, 30°, 45°, 60°, 75° and 90°, respectively. The results show that the strength, plasticity and the failure modes vary with θf. At θf =0°, the composite possesses the highest strength and the largest plasticity. When θf are 45° and 90°, the composites show relatively low compressive strength and plasticity. At θf≥15°, the composites fail in different shear modes. The composites fail by in-plane sliding at 0°<θf≤45°, while the composites fail by out-of-plane sliding at 45°<θf≤90°.
Co-reporter:Changqin Zhang, Zhengwang Zhu, Haifeng Zhang, Zhuangqi Hu
Journal of Non-Crystalline Solids 2012 Volume 358(Issue 1) pp:61-64
Publication Date(Web):1 January 2012
DOI:10.1016/j.jnoncrysol.2011.08.023
Decolorization property of Fe–Mo–Si–B ribbons with different structures was investigated, and kinetic analyses elucidated that the decolorization process could be described by a pseudo-first-order kinetic model. Amorphous ribbons were proved to decolorize Acid Orange II solutions much more rapidly than amorphous/nanocrystalline ribbons at the same temperatures. Activation energies of the decolorization process by amorphous ribbons and amorphous/nanocrystalline ribbons were obtained according to Arrhenius equation, and they were proved more or less the same because of the existence of amorphous phase in both ribbons, while the different reactive site amount was considered to lead to the different decolorization rates for the two ribbons with different structures.Highlights► We studied decolorization property of Fe–Mo–Si–B ribbons with different structures. ► Amorphous ribbons decolorize the dye solution much more rapidly. ► Activation energies were more or less the same for the two ribbons. ► Different reactive site amount leads to the different decolorization rates.
Co-reporter:Bo Zhang, Huameng Fu, Zhengwang Zhu, Aimin Wang, Hong Li, Chuang Dong, Zhuangqi Hu, Haifeng Zhang
Materials Science and Engineering: A 2012 540() pp: 207-211
Publication Date(Web):
DOI:10.1016/j.msea.2012.01.127
Co-reporter:Z.W. Zhu, L. Gu, G.Q. Xie, W. Zhang, A. Inoue, H.F. Zhang, Z.Q. Hu
Acta Materialia 2011 Volume 59(Issue 7) pp:2814-2822
Publication Date(Web):April 2011
DOI:10.1016/j.actamat.2011.01.020
Abstract
The relation between icosahedral short-range ordering (ISRO) and plastic deformation was investigated in Zr70−xNbxCu13.5Ni8.5Al8 (at.%, x = 0, 2, 4, 6, 7, 8, 10) bulk metallic glasses (BMG). The formation of icosahedral quasicrystal (I-phase) during the annealing process implies that ISRO widely exists in these materials. The degree of ISRO is thermodynamically evaluated to show that ISRO increases with increasing Nb content. Compression tests indicate that BMG with 0–7 at.% Nb possess similar unusual plastic deformability, which is attributed to ISRO-mediated local distribution of free volume (FV) and ISRO prompted deformation-induced crystallization. A proposed core–shell model coupled with transmission electron microscopy analysis demonstrates that the FV is distributed more heterogeneously with increasing ISRO, which is beneficial for multiplying the shear bands. Deformation-induced crystallization is facilitated, owing to the low interfacial energy of the nucleation and growth of the crystals attributed to ISRO in the amorphous matrix, which improves plasticity by consuming energy and the product altering the stress field in the amorphous matrix. Design of new ductile BMG is discussed in these strategies.
Co-reporter:Yongli Chen, Aimin Wang, Huameng Fu, Zhengwang Zhu, Haifeng Zhang, Zhuangqi Hu, Lu Wang, Huanwu Cheng
Materials Science and Engineering: A 2011 530() pp: 15-20
Publication Date(Web):
DOI:10.1016/j.msea.2011.08.063
Co-reporter:ChangQin Zhang;ZhengWang Zhu;ZhuangQi Hu
Science Bulletin 2011 Volume 56( Issue 36) pp:3988-3992
Publication Date(Web):2011 December
DOI:10.1007/s11434-011-4781-8
An Fe-based amorphous alloy was found to significantly enhance the reductive degradation of an azo dye in aqueous solution. The surface-area normalized rate constant was up to 2.0 L m−2 min−1 at room temperature, an order of magnitude larger than any previously reported value. The activation energy of the degradation process was calculated according to the Arrhenius equation, and a much lower value than those previously reported was obtained. Valence band measurement indicated that a depressed valence band maximum and a widened empty band were established in the amorphous ribbon. The unique structure of the amorphous alloy is important — it may reduce the activation energy of the degradation process and enhance the activity of the electrons, thus accelerating the degradation process.
Co-reporter:DengKe Li;AiMin Wang;ZhengWang Zhu
Science Bulletin 2011 Volume 56( Issue 36) pp:3926-3931
Publication Date(Web):2011 December
DOI:10.1007/s11434-011-4763-x
The effect of tin (Sn) addition on the glass forming ability (GFA) and mechanical properties of the Ni-Nb-Zr ternary alloy system has been studied. The addition of Sn improves the GFA; Ni61Nb35.5−xZr3.5Snx (in at.%) alloys with x=1 can be cast into amorphous samples at least 3 mm in diameter using a copper mold injection-casting method. The critical size for glass formation decreases to 2 mm when x=5 because Ni2SnZr phase precipitates readily. The addition of Sn is also effective in enhancing the stability of the supercooled liquid; a maximum supercooled liquid region of 48 K was attained for the Ni61Nb30.5Zr3.5Sn5 alloy. Compression tests reveal that the Ni61Nb33.5Zr3.5Sn2 alloy possesses the best mechanical properties, with yield strength ∼3180 MPa, fracture strength ∼3390 MPa and plastic strain ∼1.3%. The fracture surfaces examined by scanning electron microscopy indicate that the alloys have a transition from ductility to brittleness in fracture behavior. The combination of high GFA, high thermal stability, high strength and compressive plasticity makes these alloys potentially attractive for engineering applications.
Co-reporter:J. Mu, Z.W. Zhu, H.F. Zhang, Z.Q. Hu, Y.D. Wang, Y. Ren
Acta Materialia 2010 Volume 58(Issue 19) pp:6267-6275
Publication Date(Web):November 2010
DOI:10.1016/j.actamat.2010.07.048
Abstract
We successfully fabricated nanocrystalline (NC) indium (In) particles embedded in Al-based amorphous matrix. Systematic investigations indicate that thermal interaction between the NC In and the amorphous matrix significantly influences their respective thermal behaviors. The melting temperature of NC In was found to be depressed by 10–30 K, owing to the specific interfacial structure of NC In/amorphous system. The simultaneous appearance of the liquid/amorphous interface destabilizes the amorphous matrix, leading to face-centered cubic-Al precipitation at the interface of In sphere/amorphous matrix at a relatively lower temperature. This effect is attributed to the diffusion of La from the matrix to the liquid In particles.
Co-reporter:Na Liu, Haifeng Zhang, Hong Li, Zhuangqi Hu
Journal of Alloys and Compounds 2010 Volume 494(1–2) pp:347-350
Publication Date(Web):2 April 2010
DOI:10.1016/j.jallcom.2010.01.032
The wetting behavior and interfaces of CuZr-based glassy alloys/W system were investigated by the sessile drop method. It was found that Cu50Zr50/W, Cu47.5Zr47.5Al5/W and Cu40Zr44Al8Ag8/W system had the final equilibrium contact angle around 18°, 8° and 3° at corresponding experimental temperatures. Base on the scanning electron microscopy observing, no reaction product can be found at the interface of Cu47.5Zr47.5Al5/W and Cu40Zr44Al8Ag8/W, and some granular reaction products appeared along the interface of Cu50Zr50/W. The present work indicates that Cu47.5Zr47.5Al5 and Cu40Zr44Al8Ag8 bulk metallic glasses (BMGs) are appropriate for the fabrication of W reinforced BMGs matrix composite.
Co-reporter:Juan Mu;Huameng Fu;Zhengwang Zhu;Aimin Wang;Hong Li;Zhuangqi Hu
Advanced Engineering Materials 2010 Volume 12( Issue 11) pp:1127-1130
Publication Date(Web):
DOI:10.1002/adem.201000163
Abstract
Melt treatment is widely used to mediate the structure of materials. Recently, it is evidenced to be a new way to improve the glass forming ability (GFA) and thermal stability of the amorphous alloys. Bulk metallic glass was obtained through this process in the Al–Ni–La alloy system. In this work, the mechanism of melt treatment on the GFA and thermal stability of the Al–Ni–La alloy was studied. A Ni-rich metastable high-melting-temperature-phase is found to occur to this alloy system. The elimination of the Ni-rich phase through the melt treatment is attributed to stabilize the thermal stability of the melt and, accordingly, enhances the GFA and thermal stability of the amorphous alloy.
Co-reporter:Jie Mao;Hai-Feng Zhang;Hua-Meng Fu;Ai-Min Wang;Hong Li;Zhuang-Qi Hu
Advanced Engineering Materials 2010 Volume 12( Issue 3) pp:170-175
Publication Date(Web):
DOI:10.1002/adem.200900264
Abstract
The effects of mold preheating temperature on the glass-forming ability of Zr64.9Al7.9Ni10.7Cu16.5 and Zr47Cu37.5Ag7.5Al8 alloys are investigated using traditional copper mold casting. It is found that there exists an optimum mold temperature for glass-forming alloy systems. For the two Zr-based alloy systems studied the optimum mold temperature is 353 K. This is explained from the perspectives of heat transfer efficiency and the wettability between liquid alloy and copper mold.
Co-reporter:M.Q. Tang, H.F. Zhang, Z.W. Zhu, H.M. Fu, A.M. Wang, H. Li, Z.Q. Hu
Journal of Materials Science & Technology 2010 Volume 26(Issue 6) pp:481-486
Publication Date(Web):June 2010
DOI:10.1016/S1005-0302(10)60077-1
Co-reporter:Changqin Zhang, Haifeng Zhang, Manqi Lv, Zhuangqi Hu
Journal of Non-Crystalline Solids 2010 Volume 356(33–34) pp:1703-1706
Publication Date(Web):15 July 2010
DOI:10.1016/j.jnoncrysol.2010.06.019
The authors recently find that (Fe0.99Mo0.01)78Si9B13 glassy ribbons have a prominent effect on the decolorization of azo dyes. Direct Blue 2B solution of 200 mg/L were found to be decolorized by the ribbons nearly completely within 30 min. Decolorization mechanism was discussed briefly, and kinetic analyses based on the experimental data elucidated that the decolorizaiton process could be described by a pseudo-first-order kinetic model. Recycled experiments proved that the ribbons could be reused at least four times without obvious decay of decolorization efficiency. Combined with low manufacturing cost of producing Fe-based glassy ribbons, this new finding seems attractive, valuable and promising for industrial applications in the future.
Co-reporter:J. Mao, H.F. Zhang, H.M. Fu, A.M. Wang, H. Li, Z.Q. Hu
Materials Science and Engineering: A 2010 527(4–5) pp: 981-985
Publication Date(Web):
DOI:10.1016/j.msea.2009.09.040
Co-reporter:J.M. Zhu, H.M. Fu, H.F. Zhang, A.M. Wang, H. Li, Z.Q. Hu
Materials Science and Engineering: A 2010 527(26) pp: 6975-6979
Publication Date(Web):
DOI:10.1016/j.msea.2010.07.028
Co-reporter:J.M. Zhu, H.M. Fu, H.F. Zhang, A.M. Wang, H. Li, Z.Q. Hu
Materials Science and Engineering: A 2010 527(27–28) pp: 7210-7214
Publication Date(Web):
DOI:10.1016/j.msea.2010.07.049
Co-reporter:G.F. Ma, H.F. Zhang, H. Li, Z.Q. Hu
Materials Letters 2009 Volume 63(18–19) pp:1605-1607
Publication Date(Web):31 July 2009
DOI:10.1016/j.matlet.2009.04.026
Using the sessile-drop method, the wettability and diffusion of the molten Bi–Sn on amorphous and crystalline Fe78B13Si9 alloy are studied at isothermal condition, and the interfacial characteristics were investigated by HRSEM and EPMA. The results show that the contact angle of Bi–Sn alloy melts on amorphous substrate is smaller than that of Bi–Sn alloy melts on the crystalline one at 423 K. The interface is continuous, while no intermediate reaction layer formed at the interface of molten Bi–Sn on amorphous and crystalline Fe78B13Si9, respectively. The width of diffusion layer of Bi–Sn alloy melts on the amorphous substrate is thinner than that on the crystalline one under identical conditions.
Co-reporter:Jie Mao;Hai-Feng Zhang;Hua-Meng Fu;Ai-Min Wang;Hong Li;Zhuang-Qi Hu
Advanced Engineering Materials 2009 Volume 11( Issue 12) pp:986-991
Publication Date(Web):
DOI:10.1002/adem.200900174
Abstract
The glass1-forming ability of two alloys, Zr64.9Al7.9Ni10.7Cu16.5 and Zr47Cu37.5Ag7.5Al8, prepared by arc-melting a mixture of Zr, Cu, Al, Ni and Ag elements is studied as a function of casting temperature. Other processing parameters such as the alloy melt mass, and the vacuum and injection pressures during the copper-mold-casting process are kept constant so just the influence of the casting temperature is considered. The casting temperature determines the characteristics of the liquid melt and the cooling rate. The glass-forming ability is discussed in terms of dissipation of pre-exiting, metastable local-ordering clusters that act as nucleation sites promoting crystallization, the cooling rate at high casting temperatures, and the presence of oxygen in the alloys, which is increased at high casting temperatures. It is found that the glass-forming ranges of alloys shrink as the glass-forming size approaches a critical value. The optimum temperatures are around 1450 K and 1550 K for Zr64.9Al7.9Ni10.7Cu16.5 and Zr47Cu37.5Ag7.5Al8 alloys respectively. The alloys were studied by XRD, TEM, oxygen-level determination, and DSC.
Co-reporter:Juan Mu;Huameng Fu;Zhengwang Zhu;Aimin Wang;Hong Li;Zhuangqi Hu
Advanced Engineering Materials 2009 Volume 11( Issue 7) pp:530-532
Publication Date(Web):
DOI:10.1002/adem.200900100
Co-reporter:H.F. Zhang, H. Li, A.M. Wang, H.M. Fu, B.Z. Ding, Z.Q. Hu
Intermetallics 2009 Volume 17(Issue 12) pp:1070-1077
Publication Date(Web):December 2009
DOI:10.1016/j.intermet.2009.05.011
Based on full understanding of wettability between Zr based bulk metallic glass (BMG) matrix and tungsten (W) fibre, and liquid/solid interfacial atomic interaction, the high density and high strength 80 vol.% W fibre/Zr based BMG composite, with optimum interfacial layer, was successfully developed by strictly controlling the infiltration and solidification process. Its density was 17 g/cm3. The average value of tensile fracture strength was 1685 MPa. Fracture mode represented instant rupture which was vertical to the axial direction. The average value of compressive fracture strength and strain were 2550 MPa and 23% respectively. Its fracture mode was complex splitting along loading direction. The initiation of shear bands occurred when the compressive specimen reached plastic strength. Shear bands' continuous expanding, branching, propagation and build up responded the improvement of plasticity under the continuous loading. Shear bands distributed on the fracture surface in two ways. One was consistent with the maximum shear force direction and at 45° angle with the loading direction. The other was nearly horizontal and vertical to the loading direction. The characteristics of plastic deformation and fracture were also investigated and discussed in detail.
Co-reporter:Y. Sun, H.F. Zhang, H.M. Fu, A.M. Wang, Z.Q. Hu
Materials Science and Engineering: A 2009 Volume 502(1–2) pp:148-152
Publication Date(Web):25 February 2009
DOI:10.1016/j.msea.2008.10.008
We study the glass forming ability (GFA) and mechanical properties of the Mg–Cu–Ag–Er bulk metallic glass (BMG) systemically in this paper. A new best glass former Mg60.5Cu19.667Ag9.833Er10 is pinpointed using systematic strategy in 3D space. The critical glass formation diameter for this alloy has improved significantly from 6 mm to 11 mm. The Mg63Cu16.8Ag11.2Er9 BMG exhibits yielding and plastic deformation during compressive loading. The fracture strength and plastic strain of Mg63Cu16.8Ag11.2Er9 BMG is 1098 MPa and 0.5%, respectively. The superior mechanical properties compare with other Mg-based BMGs are attributed to the introduction of Er.
Co-reporter:G.F. Ma, H.L. Zhang, H.F. Zhang, H. Li, Z.Q. Hu
Journal of Alloys and Compounds 2008 Volume 464(1–2) pp:248-251
Publication Date(Web):22 September 2008
DOI:10.1016/j.jallcom.2007.09.137
The wettabilities of In–Sn alloy on Cu40Zr44Al8Ag8 BMG substrate were investigated using the sessile-drop method at different temperature. The result shows that the equilibrium contact angle decreased with increasing temperature. The interfacial reaction of the active Sn atoms in molten In–Sn alloy and the active Zr atoms in Cu40Zr44Al8Ag8 BMG caused crystallization reaction. Ion beam sputtering profiling in combination with AES technique was employed to investigate the Sn diffusion in Cu40Zr44Al8Ag8 BMG. Between 473 K and 673 K, the diffusion coefficients vary from 0.7 × 10−16 m2/s to 12.9 × 10−16 m2/s. It is concluded that the interfacial reaction is favorable to the crystallization and then the crystallization also promotes Sn diffusion.
Co-reporter:R.D. Ma, H.F. Zhang, H.S. Yu, Z.Q. Hu
Journal of Alloys and Compounds 2008 Volume 454(1–2) pp:370-373
Publication Date(Web):24 April 2008
DOI:10.1016/j.jallcom.2006.12.071
In this paper, a systematic investigation about the effect of Al substitution on properties of Fe–Cr–Mo–Er–C–B amorphous material, including glass-forming ability (GFA), thermal properties, and mechanical properties was presented. It was found out by X-ray diffraction (XRD) that the glass-forming ability decreased with the increase of Al, when Al reached 7 at%, fully amorphous specimen was not obtained. With regard to thermal parameters, such as glass transition temperature Tg, crystallization temperature Tx, supercooled liquid region ΔTx, and reduced glass temperature Trg were checked by differential scanning calorimeter. A rather wide supercooled liquid region more than 40 K was found. During compression test, results showed Al substitution slightly improved the fracture strength from 3.4 to 3.7 GPa. The fracture morphology was observed by scanning electron microscopy. Micrographs showed the same cleavage-like fracture in spite of different Al substitution.
Co-reporter:G.F. Ma, H.F. Zhang, H. Li, Z.Q. Hu
Journal of Alloys and Compounds 2008 Volume 462(1–2) pp:343-346
Publication Date(Web):25 August 2008
DOI:10.1016/j.jallcom.2007.08.049
Alumina ceramics are stable materials in contact with metallic melts and bulk metallic glasses (BMGs) may be used as metal–matrix composites (MMCs). In this study, the wetting behavior and metal-oxide interfaces in the CuZr-based BMGs/alumina system were investigated by the sessile drop method in a high vacuum furnace. It was found that Cu50Zr50, Cu45Zr48Al7 and Cu40Zr44Al8Ag8 BMG presented final equilibrium contact angle values around 43°, 13° and 2° at respective temperature of melting point. The samples were cut transversaly and characterized by scanning electron microscopy (SEM) and electronic probe microscopic analyzer (EPMA). The interface was continuous and no intermediate reaction layer was formed at the interface of CuZr-based BMGs/alumina. However, diffusion band was observed at the fringe of metallic drop.
Co-reporter:G.F. Ma, N. Liu, H.F. Zhang, H. Li, Z.Q. Hu
Journal of Alloys and Compounds 2008 Volume 456(1–2) pp:379-383
Publication Date(Web):29 May 2008
DOI:10.1016/j.jallcom.2007.02.086
Wetting behavior of amorphous Fe78B13Si9 substrate by molten Bi–Sn alloy was investigated by sessile drop technique. Liquid–solid reaction and the crystallization reaction occur in the reactive zone of the liquid/solid interface. We found that the equilibrium contact angle on amorphous Fe78B13Si9 substrate does not decrease monotonically with increasing temperature. Pre-annealing of amorphous Fe78B13Si9 made the equilibrium contact angle increase with the increase of the pre-annealing temperature. We propose that the crystallization reaction in the interface provides an additional driving force for the observed spreading process. By analyzing wetting kinetics, three wetting stages were identified in the wetting process.
Co-reporter:G.F. Ma, H.L. Zhang, H.F. Zhang, H. Li, Z.Q. Hu
Materials Letters 2008 Volume 62(12–13) pp:1853-1855
Publication Date(Web):30 April 2008
DOI:10.1016/j.matlet.2007.10.026
Co-reporter:Jieqiong Li, Lu Wang, Haifeng Zhang, Zhuangqi Hu, Hongnian Cai
Materials Letters 2007 Volume 61(11–12) pp:2217-2221
Publication Date(Web):May 2007
DOI:10.1016/j.matlet.2006.08.077
Bulk Mg65Cu20Ag5Gd10 metallic glass matrix composites reinforced by SiC particulates were synthesized and characterized. Thermal stability and glass forming ability of the matrix are not significantly affected by the particle addition. Compressive fracture strength of the SiC particulates reinforced composite reached about 963 MPa, a factor of 1.2 higher than monolithic glass. A small quantity of Si atoms diffusion can be detected in the composite, but no reaction layer can be observed.
Co-reporter:W.Y. Liu, H.F. Zhang, A.M. Wang, H. Li, Z.Q. Hu
Materials Science and Engineering: A 2007 Volume 459(1–2) pp:196-203
Publication Date(Web):25 June 2007
DOI:10.1016/j.msea.2007.01.033
Six mathematical criteria used for quantitatively measuring their glass forming ability, thermal stability and characteristic temperatures (temperature of glass transition Tg, crystallization onset Tx and liquidus Tl) of various bulk metallic glasses (BMGs) have been proposed in this article. It is found that the criteria are suitable for evaluating these quantities for BMGs. The estimated results are better than those calculated by Fang et al.'s models and Lu et al.'s γ criterion, but our analyses indicate that these criteria, defined by the data (Pauling electronegativity xi, atomic radius ri, electron concentration ni and melting temperature Tmi) easily found in literatures, still need to be further refined in future research for shortcomings of the parameters.
Co-reporter:H.M. Fu, H. Wang, H.F. Zhang, Z.Q. Hu
Scripta Materialia 2006 Volume 55(Issue 2) pp:147-150
Publication Date(Web):July 2006
DOI:10.1016/j.scriptamat.2006.03.052
A new Cu-based bulk metallic glass of 10 mm diameter was successfully prepared by a conventional copper mold casting method using alloy Cu46Zr45Al7Gd2. The addition of Gd effectively alleviates the harmful effects of oxygen in the melt by the preferential formation of gadolinium oxide and significantly increases the glass-forming ability. The Trg = Tg/Tm reaches a maximum value of 0.694 for the Cu46Zr45Al7Gd2 alloy, which is consistent with the experimental results.
Co-reporter:J. Cai, G.C. Ma, Z. Liu, H.F. Zhang, Z.Q. Hu
Journal of Alloys and Compounds 2006 Volume 422(1–2) pp:92-96
Publication Date(Web):28 September 2006
DOI:10.1016/j.jallcom.2005.11.054
This paper presents differences of microstructure between conventionally casting and rapidly solidified AZ91HP alloy. The experimental results showed that rapid solidification changed the morphology of microstructure. The grain size was refined and homogeneously distributed β-Mg17Al12 phase was obtained. High cooling rate increased nucleation sites of α-Mg, refined microstructure and decreased the proportion of brittle β-Mg17Al12 in the eutectic (α-Mg and β-Mg17Al12). The decrease of microporosity should be attributed to the grain refinement and application of copper mould.
Co-reporter:H.M. Fu, H. Wang, H.F. Zhang, Z.Q. Hu
Scripta Materialia 2006 Volume 54(Issue 11) pp:1961-1966
Publication Date(Web):June 2006
DOI:10.1016/j.scriptamat.2006.01.048
Cu-based bulk metallic glass (BMG) composites containing in situ TiB particles were successfully fabricated. The reinforcing TiB particles with a size of 5–10 μm are uniformly distributed in the amorphous matrix. The particles have a good bonding to the matrix with a reaction layer. The BMG composites exhibit an obvious ductility with a plastic strain of 2% for the 17.5 vol.% TiB sample due to the suppression of shear band propagation and the generation of multiple shear bands during compressive testing. The hardness of the materials is increased from Hv543 for monolithic BMG to Hv650 for 23.6 vol.% TiB-containing BMG composite.
Co-reporter:Z. Zhu;H. Zhang;D. Pan;W. Sun;Z. Hu
Advanced Engineering Materials 2006 Volume 8(Issue 10) pp:
Publication Date(Web):24 OCT 2006
DOI:10.1002/adem.200600105
Co-reporter:Huameng Fu, Haifeng Zhang, Hao Wang, Qingsheng Zhang, Zhuangqi Hu
Scripta Materialia 2005 Volume 52(Issue 7) pp:669-673
Publication Date(Web):April 2005
DOI:10.1016/j.scriptamat.2004.10.031
Cu-based bulk metallic glass matrix composites (BMGMCs) containing in-situ TiC particles were fabricated successfully. The yield and fracture strength increased from 1930 MPa, 2250 MPa to 2210 MPa, 2500 MPa, respectively. The ductility was improved and the hardness was also enhanced by 25%. The fracture mechanism was investigated in detail.
Co-reporter:W.Y. Liu, H.F. Zhang, Z.Q. Hu, H. Wang
Journal of Alloys and Compounds 2005 Volume 397(1–2) pp:202-206
Publication Date(Web):19 July 2005
DOI:10.1016/j.jallcom.2005.01.043
Mg65Cu25Er10 and Mg65Cu15Ag10Er10 bulk amorphous alloys were produced by a copper mould casting method. The alloys have high glass-forming ability and good thermal stability. The maximum diameter of glass formation (Dc), glass transition temperature (Tg), crystallization onset temperature (Tx), temperature interval of the supercooled region (ΔTx), melting temperature (Tm), liquidus temperature (Tl) as well as heats of crystallization (ΔHx) and melting (ΔHm) are reported for these alloys. Both alloys exhibit high hardness and high strength at room temperature.
Co-reporter:L. Qi, H.F. Zhang, Z.Q. Hu
Intermetallics 2004 Volume 12(10–11) pp:1191-1195
Publication Date(Web):October–November 2004
DOI:10.1016/j.intermet.2004.04.003
Based on the embedded-atom method, a constant-pressure, constant-temperature molecular dynamics technique is applied to obtain an atomic description of glass formation process in eutectic Cu40Ag60 alloy. By using radial distribution function and pair analysis methods, the structure and glass forming ability of this alloy is studied by quenching from the liquid at different cooling rates (1×1011, 1×1012, 5×1012, 1×1013 and 1×1014 K/s). It is observed that the retention of amorphous structure requires extremely high cooling rates. Structure analyses of the alloys in the simulations reveal the evolvement of the different clusters at various quenching rate during the quenching process.
Co-reporter:F.X. Qin, H.F. Zhang, B.Z. Ding, Z.Q. Hu
Intermetallics 2004 Volume 12(10–11) pp:1197-1203
Publication Date(Web):October–November 2004
DOI:10.1016/j.intermet.2004.04.015
The bulk amorphous alloy Ni45Ti23Zr15Si5Pd12 has been prepared by copper mold casting. The crystallization kinetics of the alloy has been investigated using differential scanning calorimetry by means of continuous heating and isothermal annealing, and the products of crystallization have been analyzed by transmission electron microscopy and X-ray diffraction. The isothermal activation energy obtained from Arrhenius equation increases in the process of crystallization transformation. The details of nucleation and growth during the isothermal crystallization are expatiated in terms of local Avrami exponent and local activation energy. Meanwhile, the origins of nanocrystal formation during the annealing process have also been discussed.
Co-reporter:K.Q. Qiu, H.F. Zhang, A.M. Wang, B.Z. Ding, Z.Q. Hu
Acta Materialia 2002 Volume 50(Issue 14) pp:3567-3578
Publication Date(Web):16 August 2002
DOI:10.1016/S1359-6454(02)00156-8
Abstract
The glass-forming ability (GFA) and thermal stability of Nd70−xFe20Al10Yx (0≤x≤15) alloys produced by melt spinning and copper-mold casting have been investigated. Ribbon samples in the composition range show a fully amorphous structure. Except Y=5 at.%, bulk amorphous alloys at least 2 mm in diameter were obtained. Both the amorphous ribbon and the bulk cylinder for the Nd55Fe20Al10Y15 alloy show a distinct glass transition temperature and a wide supercooled liquid region before crystallization. It is suggested to use a new parameter to characterize both the GFA and the thermal stability of Nd–Fe–Al–Y alloys, showing that Nd60Fe20Al10Y10 alloy is the best one both in GFA and thermal stability. The remanence (Jr), magnetization (J1500), and coercivity (Hc) for the as-cast Nd70−xFe20Al10Yx amorphous cylinders depend strongly on the composition. The enhanced GFA and thermal stability as well as the reduction of magnetic properties are discussed.
