|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Influence of the lithium content on the negative difference effect of Mg-Li alloys显示文摘The so-called 'negative difference effect'(NDE) was often defined by the increasing rate of hydrogen evolution from magnesium(Mg) surface under anodic polarization.In this work,a series of electrochemical tests and microstructure observations were performed to provide an evidence that the NDE of Mg-Li alloys can be retarded by increasing lithium content.Potentiostatic,galvanostatic and potentiodynamic polarization experiments using Mg-xLi(x=4,7.5 and 14 wt%) alloys electrodes indicated that Mg-4 Li alloy maintained the enhancing NDE prior to anodic dissolution as that of conventional Mg alloys.However,the emergence of β-Li phase weakened the NDE of duplex Mg-7.5 Li alloy at a low anodic current density,but it was still enhanced apparently after a high applied anodic value(more than 2 mA/cm^2).The surface observations,including the plane and cross-sectional morphologies,confirmed that the cracked surface film derived from the anodic dissolution resulted in the catalytic activity of NDE for Mg-4 Li and Mg-7.5 Li alloys.Furthermore,the NDE of Mg-14 Li alloy was suppressed obviously after a prior applied anodic polarization,which was attributed to the persistent and integrated surface film which endured a higher level of applied anodic potential and current. | C.Q.Li D.K.Xu Z.R.Zhang E.H.Han | 2020 | Journal of Materials Science & Technology2020，54，22： | 5 |
| 2 | Mechanisms of eutectic lamellar destabilization upon rapid solidification of an undercooled Ag-39.9 at.% Cu eutectic alloy显示文摘The eutectic Ag-Cu alloys exhibiting fine Ag-Cu lamellar eutectic structure formed upon rapid solidification have great potentials being used in various engineering fields.However,the desired fine primary lamellar eutectic structure(PLES)is usually replaced by a coarse anomalous eutectic structure(AES)when the undercooling prior to solidification exceeds a certain value.The forming mechanism of AES in the undercooled eutectic Ag-Cu alloy has been a controversial issue.In this work,the undercooled Ag-39.9 at.% Cu eutectic alloy is solidified under different cooling conditions by using techniques of melt fluxing and copper mold casting.The results show that the coupled eutectic growth of this alloy undergoes a transition from a slow eutectic-cellular growth(ECG)to a rapid eutectic-dendritic growth(EDG)above a undercooling of 72 K,accompanying with an abrupt change of the distribution and amount of AES in as-solidified microstructures.Two kinds of primary lamellar eutectic structures are formed by ECG and EDG during recalescence,respectively.The destabilization of PLES that causes the formation of AES is ascribed to two different mechanisms based on the microstructural examination and theoretical calculations.Below 72 K,the destabilization of PLES formed by slow ECG is caused by the mechanism of'termination migration'driven by interfacial energy.While above 72 K,the destabilization of PLES formed by rapid EDG is attributed to the unstable perturbation of interface driven by interfacial energy and solute supersaturation. | H.Dong Y.Z.Chen Z.R.Zhang G.B.Shan W.X.Zhang F.Liu | 2020 | Journal of Materials Science & Technology2020，59，24： | 2 |
| 3 | 新型大环配体-BDBPH合成及其晶体结构显示文摘目的 利用分子设计 ,合成新型大环多胺配体BDBPH ,研究其合成工艺及晶体结构。方法 2 ,6 二甲酰基对甲苯酚 ,二亚乙基三胺 ,Pb(SCN) 2 三种化合物在CHCl3溶液中 50~ 6 0℃反应 18h ,随后经NaBH4 还原、脱Pb2 + 等操作 ,得晶体产品BDBPH ,用1HNMR、FAB—MS、元素分析确定了其结构 ,用单晶X 射线衍射法测定其晶体结构。结果 1HNMR(D2 O) ,δ(ppm) :2 .13(s , CH3,6H) ,3.35(q ,ethylene ,16H) ,4 .2 1(s , CH2 ,8H) ,7.16 (s ,Ary1,4H) ;FAB MS :4 71(M +H ) ;元素分析 ,计算值 (BDBPH·6HBr·4H2 O) :C 30 .35,H 5.4 4 ,N 8.17,实测值 :C 30 .2 2 ,H 5.4 6 ,N7.98。晶体属单斜晶系 ,P2 1/C空间群 ,晶体学参数 :a =14.4 4 1(5) ,b =11.4 82 (4 ) ,c =12 .0 90 (6 ) ,α =90 ,β =96 .92 (3) ,γ =90℃ ,V =1990 .0 (14) 3。大环分子采取椅式构型 ,6个Br- ,4个H2 O分子对称分布于大环两侧。结论 该大环配体合成工艺先进 ,晶体结构新颖 ,可用于多种金属配合物的研究 ,对进一步了解金属酶的结构及其催化作用机制具有重要意义。 | 上官国强 A.E.Martell Z.R.Zhang J.Reibenspie | 2000 | 济宁医学院学报2000，23，1： | 2 |
| 4 | A novel Mg-Gd-Y-Zn-Cu-Ni alloy with excellent combination of strength and dissolution via peak-aging treatment显示文摘Inferior absolute strength and dissolution properties are the main bottlenecks for the widespread application of dissolvable magnesium alloys in complex working environments for unconventional oil and gas resources.Here,a novel functional peak-aged Mg-9.5Gd-2.7Y-0.9Zn-0.8Cu-0.4Ni(wt.%) alloy for fracturing tools is reported,and it possesses an ultimate tensile strength of 457.6 MPa,ultimate compressive strength of 620.7 MPa and dissolution rate of ~43.7 mg·cm^(-2)·h^(-1) in 3 wt.% KCl solutions at 93℃.The excellent strength of the agedalloy is primarily attributed to the combination of grain refinement,long-period stacking ordered(LPSO) strengthening,and precipitation strengthening induced by stacking fault and β’ phase,among which the precipitation strengthening is dominant.Further investigations confirm that the corrosion is triggered from the micro-galvanic coupling between the Mg matrix and the cathodic lamellar and block LPSO phases.Strip-shaped corrosion pits along with LPSO phases are subsequently formed,significantly accelerating corrosion.The β’ precipitates can effectively improve the strength without compromising the dissolution rate because of their nanoscale size.This study provides an excellent material selection for dissolvable fracturing tools and presents a strategy by which a synergistic combination of strength and dissolution rate is achieved via peak-aging treatment. | Y.H.Liu Z.R.Zhang J.Wang Y.Li H.X.Li L.Y.Jia J.H.Wang J.S.Zhang | 2023 | Journal of Magnesium and Alloys2023，11，2： | 1 |
| 5 | A novel direct reduction method to synthesize ordered Fe-Pt alloy nanoparticles显示文摘In this work, a direct green solid-phase reduction method for the fabrication of large yield of ordered phase Fe-Pt alloy nanoparticles was reported, in which inorganic salts were used as metal precursors and H_2-containing atmosphere was used as reducer. Utilizing this method, the composition and chemical ordered phase, such as L1_2-Fe_3 Pt, L1_2-FePt_3, and L1_0-FePt phases can be easily achieved by one step reaction. The synthesized nanoparticles have clean surface because no organic precursors, no organic solutions or organic surfactants/ligands were used. Their magnetic performance and the formation mechanism of Fe-Pt alloy nanoparticles were also investigated. This strategy can be applied to synthesize many other types of alloy nanoparticles with desired composition and necessary crystal structure, which can be used for a variety of practical applications, such as in magnetism and catalyst research fields. | Q.Zheng Z.R.Zhang J.Du L.L.Lin W.X.Xia J.Zhang B.R.Bian J.P.Liu | 2019 | Journal of Materials Science & Technology2019，35，4： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员