期刊文献+
共找到15,273篇文章
< 1 2 250 >
每页显示 20 50 100
Crystal structure and hydrogen storage properties of(La,Ce)Ni5-xMx(M=Al,Fe,or Co)alloys 预览
1
作者 Wan-liang Mi Zhao-sen Liu +2 位作者 Toru Kimura Atsunori Kamegawa Hai-liang Wang 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第1期108-113,共6页
The effects of partial substitution of La by Ce and Ni by Al,Fe,or Co in LaNi5-based alloys on hydrogen storage performance were systematically studied.All samples were prepared using vacuum arc melting in an argon at... The effects of partial substitution of La by Ce and Ni by Al,Fe,or Co in LaNi5-based alloys on hydrogen storage performance were systematically studied.All samples were prepared using vacuum arc melting in an argon atmosphere.The results showed that for La-Ni5-xMx(M=Al,Fe,or Co)alloys,the lattice constants and unit cell volumes increased with an increasing amount of Al and Fe.On the other hand,these parameters decreased upon partial substitution of La by Ce.In addition,the lattice constant remained almost constant in the La0.6Ce0.4Ni5–xCox alloys regardless of the value of x(x=0.3,0.6,or 0.9),as Ce might enhance the homogeneity of the CaCu5-type phase in Co-containing alloys.The hydrogen storage properties of the alloys were investigated using pressure,composition,and temperature isotherms.The experimental results showed that the plateau pressure decreased with an increasing content of Al,Fe,or Co,but it increased with Ce addition.Furthermore,the plateau pressures of all Co-containing alloys were almost identical upon substitution with Ce.Finally,the enthalpy(ΔH)and entropy(ΔS)values for all alloys were calculated using van’t Hoff plots.The relationship between the lattice parameters and enthalpy changes for hydrogenation will be discussed. 展开更多
关键词 metal HYDRIDE LANI5 hydrogen storage ALLOYS partial SUBSTITUTION P-C-T CURVES thermodynamics
在线阅读 下载PDF
Effect of Mo Addition on Corrosion Behavior of High-Entropy Alloys CoCrFeNiMo_x in Aqueous Environments
2
作者 Xu-Liang Shang Zhi-Jun Wang +3 位作者 Qing-Feng Wu Jin-Cheng Wang Jun-Jie Li Jia-Kang Yu 《金属学报:英文版》 SCIE EI CAS CSCD 2019年第1期41-51,共11页
The corrosion behavior of CoCrFeNiMox alloys was investigated in aqueous environments, NaCl and H2SO4 solutions,respectively, to simulate typical neutral and acidic conditions. The cyclic polarization curves in NaCl a... The corrosion behavior of CoCrFeNiMox alloys was investigated in aqueous environments, NaCl and H2SO4 solutions,respectively, to simulate typical neutral and acidic conditions. The cyclic polarization curves in NaCl and the potentiodynamic curves in H2SO4 clearly reveal the beneficial effects of Mo and the detrimental effect of σ-phase on the corrosion resistance. The X-ray photoelectron spectroscopy results of CoCrFeNiMox alloys in H2SO4 solution indicate that Cr and Mo predominate the corroded surface of the alloys, where Mo primarily exists in the form of MoO3. 展开更多
关键词 High-entropy alloys Corrosion σ-phase MOLYBDENUM
Enhanced elevated temperature wear resistance of Al-17Si-5Cu alloy after a novel short duration heat treatment 预览
3
作者 Biplab Hazra Supriya Bera Bijay Kumar Show 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第3期360-368,共9页
The goal of the present study is to improve the elevated temperature wear resistance of an Al-17 wt%Si-5 wt%Cu alloy(AR alloy) by a novel short duration heat treatment process. The elevated temperature(100°C) dry... The goal of the present study is to improve the elevated temperature wear resistance of an Al-17 wt%Si-5 wt%Cu alloy(AR alloy) by a novel short duration heat treatment process. The elevated temperature(100°C) dry sliding wear behavior of an AR alloy was studied after microstructural modification using the proposed heat treatment. The study revealed considerable microstructural modifications after the heat treatment and the heat treated alloy was designated as HT(heat treatment) alloy. A higher hardness value was obtained for the HT alloy compared to the AR alloy. Accordingly, the wear rate for the HT alloy was found to be significantly lower compared to the as-cast AR alloy at all applied loads. Accelerated particle pull-out for the AR alloy at elevated temperatures resulted in poor wear behavior for it compared to the HT alloy. On the other hand, the Si particles remained intact on the worn surface of the HT alloy due to the good particle/matrix bonding that resulted from the isothermal heat treatment. Furthermore, the age hardening that occurred in the HT alloy during wear provided additional wear resistance. Thus, the HT alloy at 100°C exhibited a lower wear rate compared to the AR alloy even at room temperature for all applied loads. This improvement was attributed to microstructural modification upon isothermal heat treatment along with the age hardening effect. 展开更多
关键词 AL-SI alloys ISOTHERMAL heat treatment wear resistance MICROSTRUCTURAL investigation
在线阅读 下载PDF
Buckling and post-buckling behavior of titanium alloy stiffened panels under shear load
4
作者 Yuru SU Zhidong GUAN +3 位作者 Xin WANG Zengshan LI Jun GUO Yongjie HUANG 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第3期619-626,共8页
Titanium alloy has been increasingly applied in aviation industry due to its superior performance. However, the titanium alloy structures are less studied. This work investigates the structural behavior of Ti6Al4V tit... Titanium alloy has been increasingly applied in aviation industry due to its superior performance. However, the titanium alloy structures are less studied. This work investigates the structural behavior of Ti6Al4V titanium alloy stiffened panels under in-plane shear load by experiments and numerical analysis. After the shear tests, the buckling instability, the post-buckling process and the failure mechanism of the specimen were obtained. The Finite Element(FE) models were established with the subsequent validation verification. A parametric analysis was implemented to study the influence of stringer thickness and stringer height on the behavior of the stiffened panels. The results show that after the initial local buckling on the skin, the buckling mode jumps several times with the increase of load. The stringers twist when the load reaches a certain level, and finally the structure damages due to the plastic deformation and the global buckling. The shear clip has little effect on the buckling and failure loads. Compared to the relatively large effect on the buckling load, the influence of the stringer thickness and stringer height on the failure load is neglectable.According to the parametric analysis, the stringer thickness influences the final buckling mode and failure mode, while the stringer height affects the buckling mode transformation. 展开更多
关键词 BUCKLING Finite Element Method(FEM) IN-PLANE shear loading Stiffened panel STRINGER HEIGHT STRINGER thickness Titanium alloys
Fatigue crack initiation of magnesium alloys under elastic stress amplitudes:A review
5
作者 B.J.WANG D.K.XU +1 位作者 S.D.WANG E.H.HAN 《机械工程前沿:英文版》 CSCD 2019年第1期113-127,共15页
The most advantageous property of magnesium(Mg)alloys is their density,which is lower compared with traditional metallic materials.Mg alloys,considered the lightest metallic structural material among others,have great... The most advantageous property of magnesium(Mg)alloys is their density,which is lower compared with traditional metallic materials.Mg alloys,considered the lightest metallic structural material among others,have great potential for applications as secondary load components in the transportation and aerospace industries.The fatigue evaluation of Mg alloys under elastic stress amplitudes is very important in ensuring their service safety and reliability.Given their hexagonal close packed structure,the fatigue crack initiation of Mg and its alloys is closely related to the deformation mechanisms of twiuning and basal slips.However,for Mg alloys with shrinkage porosities and inclusions,fatigue cracks will preferentially initiate at these defects,remarkably reducing the fatigue lifetime.In this paper,some fundamental aspects about the fatigue crack initiation mechanisms of Mg alloys are reviewed,in cluding the 3 followings:1)Fatigue crack initiation of as-cast Mg alloys,2)influence of microstructure on fatigue crack initiation of wrought Mg alloys,and 3)the effect of heat treatment on fatigue initiation mechanisms.Moreover,some unresolved issues and future target on the fatigue crack initiation mechanism of Mg alloys are also described. 展开更多
关键词 Mg alloys FATIGUE behavior microstructure CRACK INITIATION DEFORMATION mechanism
In vitro corrosion resistance and antibacterial performance of noveltin dioxide-doped calcium phosphate coating on degradable Mg-1Li-1Ca alloy
6
作者 Lan-Yue Cui Guang-Bin Wei +6 位作者 Zhuang-Zhuang Han Rong-Chang Zeng Lei Wang Yu-Hong Zou Shuo-Qi Li Dao-Kui Xu Shao-Kang Guan 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第3期254-265,共12页
A SnO2-doped calcium phosphate(Ca-P-Sn) coating was constructed on Mg-1 Li-1 Ca alloy by a hydrothermal process. The fabricated functional coatings were investigated using scanning electron microscopy(SEM), X-ray diff... A SnO2-doped calcium phosphate(Ca-P-Sn) coating was constructed on Mg-1 Li-1 Ca alloy by a hydrothermal process. The fabricated functional coatings were investigated using scanning electron microscopy(SEM), X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FT-IR). A triple-layered structure, which is composed of Ca3(PO4)2,(Ca, Mg)3(PO4)2, SnO2, and MgHPO4·3 H2O, is evident and leads to the formation of Ca10(PO4)6(OH)2 in Hank’s solution. Electrochemical measurements, hydrogen evolution tests and plating counts reveal that the corrosion resistance and antibacterial activity were improved through the coating treatment. The embedded SnO2 nanoparticles enhanced crystallisation of the coating.The formation and degradation mechanisms of the coating were discussed. 展开更多
关键词 MAGNESIUM alloys Coatings Corrosion BIOMEDICAL materials
High performance GaSb based digital-grown InGaSb/AlGaAsSb mid-infrared lasers and bars
7
作者 谢圣文 张宇 +8 位作者 杨成奥 黄书山 袁野 张一 尚金铭 邵福会 徐应强 倪海桥 牛智川 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第1期411-414,共4页
InGaSb/AlGaAsSb double-quantum-well diode lasers emitting around 2 μm are demonstrated. The AlGaAsSb barriers of the lasers are grown with digital alloy techniques consisting of binary AlSb/AlAs/GaSb short-period pai... InGaSb/AlGaAsSb double-quantum-well diode lasers emitting around 2 μm are demonstrated. The AlGaAsSb barriers of the lasers are grown with digital alloy techniques consisting of binary AlSb/AlAs/GaSb short-period pairs. Peak power conversion efficiency of 26% and an efficiency higher than 16% at 1 W are achieved at continuous-wave operation for a 2-mm-long and 100-μm-wide stripe laser. The maximum output power of a single emitter reaches to 1.4 W at 7 A.19-emitter bars with maximum efficiency higher than 20% and maximum power of 16 W are fabricated. Lasers with the short-period-pair barriers are proved to have improved temperature properties and wavelength stabilities. The characteristic temperature(T0) is up to 140?C near room temperature(25–55?C). 展开更多
关键词 MID-INFRARED laser diode DIGITAL alloys characteristic temperature BARS
Joints of continuous carbon fiber reinforced lithium aluminosilicate glass ceramics matrix composites to Ti60 alloy brazed using Ti-Zr-Ni-Cu active alloy
8
作者 Shengpeng HU Dongdong FENG +5 位作者 Long XIA Ke WANG Renwei LIU Zhentao XIA Hongwei NIU Xiaoguo SONG 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第3期715-722,共8页
Continuous carbon fiber reinforced lithium aluminosilicate glass ceramics matrix composites(Cf/LAS composites) are joined to Ti60 alloy vacuum brazed using Ti-Zr-Ni-Cu brazing alloy. The effects of the brazing tempera... Continuous carbon fiber reinforced lithium aluminosilicate glass ceramics matrix composites(Cf/LAS composites) are joined to Ti60 alloy vacuum brazed using Ti-Zr-Ni-Cu brazing alloy. The effects of the brazing temperature on the interfacial microstructure and mechanical properties of brazed joints are investigated in details. The interfacial microstructure varies apparently with an increase of the brazing temperature. The thicknesses of the banded Ti solid solution(Ti(s, s)) and the reactive layer between Cf/LAS composites and the interlayer grow gradually. The mechanical properties of brazed joints increase firstly and then decrease with an increasing temperature. In addition, a joint that is brazed at 980℃ for 10 min shows the highest shear strength of$38.13 MPa. At the same time, the fracture paths of brazed joints also change as the temperature increases. When the brazing temperature is 950℃, the fracture position is in the TiC + ZrC +Ti2O + ZrSi2+ Ti5Si3 layer on the composite side. When the brazing temperature is 980℃, the fracture position is on the side of the braze seam(Ti, Zr)2(Ni, Cu), Ti2O + ZrSi2+ Ti5Si3 layer,and carbon fiber in the composite material. When the brazing temperature is 990℃, the fracture position is in the Ti2O + ZrSi2+ Ti5Si3 layer on the composite side and the carbon fiber in the composite material. 展开更多
关键词 BRAZING COMPOSITES Mechanical properties Microstructure TITANIUM alloys
A New Spot Welding Technique for Fuselage 预览
9
作者 CHEN Dan CHAI Peng +2 位作者 ZHAO Huaxia XIONG Jiangtao LI Jinglong 《材料导报》 EI CAS CSCD 北大核心 2019年第10期1595-1596,共2页
High strength aluminum alloys(series 2XXX and 7XXX)are kinds of precipitation-hardening alloys,which have been widely applied in manufacturing of fuselage for their high strength-to-weight ratio,good fatigue performan... High strength aluminum alloys(series 2XXX and 7XXX)are kinds of precipitation-hardening alloys,which have been widely applied in manufacturing of fuselage for their high strength-to-weight ratio,good fatigue performance and damage tolerance[1-2].These structures mostly adopt lap joint.The traditional joining methods include riveting and bolting,which cost weight-increase and inefficiency.These disadvantages could be overcome by a new joining technique—friction stir spot welding(FSSW)developed from friction stir welding(FSW).However,after wel-ding,FSSW normally leaves the workpiece with a keyhole,which decreases mechanical properties and corrosion resistance of the joint.To fill the keyhole,refill friction stir spot welding(RFSSW,Refill-FSSW)was invented by GKSS in 1999.GKSS designs a special welding tool for RFSSW,consisting of pin,sleeve and clamping ring,which are precisely assembled with indepen-dent driving systems[3].In a typical RFSSW process,the pin and sleeve move in opposite direction at a given speed ratio.Approximately,the speeds are set inverse proportional to their cross-sectional area.In 2011,GKSS performed RFSSW on aluminum alloy and obtained the joint with good strength.Thereafter,RFSSW was highlighted in research,which was expected to apply in fuselage manufacturing and to replace the traditional joining methods. 展开更多
关键词 HIGH STRENGTH ALUMINUM ALLOYS kinds
在线阅读 免费下载
In situ growth of N-doped carbon coated CoNi alloy with graphene decoration for enhanced HER performance 预览
10
作者 Linlin Chen Saisai Yang +3 位作者 Kun Qian Wei Wei Cheng Sun Jimin Xie 《能源化学:英文版》 SCIE EI CAS CSCD 2019年第2期129-135,共7页
Non-noble metal-based catalysts,especially stable ones,have gained increasing attentions in the field of electronically catalytic hydrogen evolution reaction(HER).In this work,an N-doped carbon confined Co–Ni alloy w... Non-noble metal-based catalysts,especially stable ones,have gained increasing attentions in the field of electronically catalytic hydrogen evolution reaction(HER).In this work,an N-doped carbon confined Co–Ni alloy with reduced graphene oxide(rGO) decoration(CoNi@N-C/rGO) was fabricated for HER.The prepared catalyst exhibited excellent HER activity in an acidic electrolyte(Tafel slope of ~133.7 m V).The results showed that the enhanced HER performance of the nanostructures is attributed to the chemical and electronic synergic effect between the confined Co–Ni alloy and r GO.Stability tests,realized via longterm potential cycles and extended electrolysis,provided the confirmation of the exceptional durability of the catalyst,which originated from the confining effect of the N-doped carbon shell.This versatile method provides a strategy for designing stable non-precious metal electrocatalysts confined by carboncoating. 展开更多
关键词 Metal alloys N-DOPED CARBON Reduced GRAPHENE OXIDES Hydrogen evolution reaction
在线阅读 下载PDF
Microstructure and Mechanical Properties of Mg–RE–TM Cast Alloys Containing Long Period Stacking Ordered Phases: A Review
11
作者 Huan Liu He Huang +4 位作者 Jia-Peng Sun Ce Wang Jing Bai Ai-Bin Ma Xian-Hua Chen 《金属学报:英文版》 SCIE EI CAS CSCD 2019年第3期269-285,共17页
Casting magnesium alloys hold the greatest share of magnesium application products due to their short processing period, low cost and near net shape forming. Compared with conventional commercial magnesium alloys or o... Casting magnesium alloys hold the greatest share of magnesium application products due to their short processing period, low cost and near net shape forming. Compared with conventional commercial magnesium alloys or other Mg–RE-based alloys, the novel Mg–RE–TM cast alloys with long period stacking ordered(LPSO) phases usually possess a higher strength and are promising candidates for aluminum alloy applications. Up to now, two ways: alloying design and casting process control(including subsequent heat treatments), have been predominantly employed to further improve the mechanical properties of these alloys. Alloying with other elements or ceramic particles could alter the solidifi cation pattern of alloys, change the morphology of LPSO phases and refi ne the microstructures. Diff erent casting techniques(conventional casting, rapidly solidifi cation, directional solidifi cation, etc.) introduce various microstructure characteristics, such as dendritic structure, nanocrystalline, metastable phase, anisotropy. Further heat treatments could activate the transformation of various LPSO structures and precipitation of diverse precipitates. All these evolutions exert great impacts on the mechanical properties of the LPSO-containing alloys. However, the underlying mechanisms still remain a subject of debate. Therefore, this review mainly provides the state of the art of the casting magnesium alloys research and the accompanying challenges and summarizes some topics that merit future investigation for developing high-performance Mg–RE–TM cast alloys. 展开更多
关键词 MAGNESIUM alloys Long period STACKING ORDERED PHASE CASTING Heat treatment PHASE TRANSFORMATIONS Mechanical properties
Characterization of the High-Strength Mg–3Nd–0.5Zn Alloy Prepared by Thermomechanical Processing
12
作者 Jirí Kubasek Drahomír Dvorsky +3 位作者 Jozef Vesely Peter Minarik Maria Zemkova Dalibor Vojtěch 《金属学报:英文版》 SCIE EI CAS CSCD 2019年第3期321-331,共11页
Magnesium alloys based on Nd and Zn are promising materials for both aviation industry and medical applications.Superior mechanical properties of these materials can be achieved by thermomechanical processing such as ... Magnesium alloys based on Nd and Zn are promising materials for both aviation industry and medical applications.Superior mechanical properties of these materials can be achieved by thermomechanical processing such as extrusion or rolling and by aging treatment, which can significantly strengthen the alloy. The question remains especially about the connection of texture strength created in the alloys based on the specific conditions of preparation. This work focuses on the Mg–3 Nd–0.5 Zn magnesium alloy prepared by hot extrusion of the as-cast state at two different temperatures combined with heat pre-treatment. Extrusion ratio of 16 and rate of 0.2 mm/s at 350 and 400 °C were selected for material preparation. The structures of prepared materials were studied by scanning electron microscopy and transmission electron microscopy. The effect of microstructure on mechanical properties was evaluated. Obtained results revealed the strong effect of thermal pre-treatment on final microstructure and mechanical properties of extruded materials. The Hall–Petch relation between grain size and tensile yield strength has been suggested in this paper based on the literature review and presented data. The observed behavior strongly supports the fact that the Hall–Petch of extruded Mg–3Nd–0.5 Zn alloys with different texture intensities cannot be clearly estimated and predicted. In addition, Hall–Petch relations presented in literature can be sufficiently obtained only for fraction of the Mg–3Nd–0.5 Zn alloys. 展开更多
关键词 Mg–Nd–Zn ALLOYS EXTRUSION THERMAL treatment MICROSTRUCTURE Mechanical properties
Microstructural evaluation and nanohardness of an AlCoCuCrFeNiTi high-entropy alloy 预览
13
作者 C.D.Gómez-Esparza R.Peréz-Bustamante +4 位作者 J.M.Alvarado-Orozco J.Munoz-Saldana R.Martínez-Sánchez J.M.Olivares-Ramírez A.Duarte-Moller 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第5期634-641,共8页
An AlCoCuCrFeNiTi high-entropy alloy (HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlCoCuCrFeNi system.The structural and microstructural characterist... An AlCoCuCrFeNiTi high-entropy alloy (HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlCoCuCrFeNi system.The structural and microstructural characteristics were investigated by X-ray diffraction (XRD),scanning electron microscopy (SEM),and transmission electron microscopy (TEM).The formation of four micrometric phases was detected: a Cu-rich phase with a face-centered cubic (fcc) structure,a body-centered cubic (bcc) solid solution with Cu-rich plate-like precipitates (fcc),an ordered bcc phase,and a tetragonal structure.The XRD patterns corroborate the presence of a mixture of bcc-,fcc-,and tetragonal- structured phases.The Vickers hardness of the alloy under study was more than twice that of the AlCoCuCrFeNi alloy.Nanoindentation tests were performed to evaluate the mechanical response of the individual phases to elucidate the relationship between chemical composition,crystal structure,and mechanical performance of the multiphase microstructure of the AlCoCuCrFeNiTi HEA. 展开更多
关键词 high-entropy ALLOYS mechanical ALLOYING microstructure NANOINDENTATION
在线阅读 下载PDF
An improved process for grain refinement of large 2219 Al alloy rings and its influence on mechanical properties
14
作者 Hailin He Youping Yi +1 位作者 Shiquan Huang Yuxun Zhang 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第1期55-63,共9页
The large 2219 Al alloy rings used to connect propellant tank components of a satellite launch vehicle to each other are conventionally manufactured by radial-axial ring rolling at 460°C with 50% deformation,but ... The large 2219 Al alloy rings used to connect propellant tank components of a satellite launch vehicle to each other are conventionally manufactured by radial-axial ring rolling at 460°C with 50% deformation,but often suffer from coarse elongated grain and low ductility. An improved process(hot ring rolling at460°C with 30% deformation, then air cooling to 240°C, followed by ring rolling at 240°C with 20% deformation) was tested for ring manufacturing. The corresponding microstructure evolution and mechanical properties of the produced rings were studied. The results show that the improved process can successfully be applied to manufacture the large 2219 Al alloy rings without formation of macroscopic defects,resulting in a product with fine and uniform grains after heat treatment. The fracture mechanism of both rings was mainly intergranular fracture. With the resulting grain size refinement due to the improved process, more homogeneous slip occured and the crack propagation path became more tortuous during the tensile testing process. Thus, the elongation in all three orthogonal directions was greatly improved,and the axial elongation increased from 3.5% to 10.0%. 展开更多
关键词 2219 Al alloys LARGE RINGS Ring ROLLING Grain REFINEMENT Mechanical properties
亲水处理前后纯钛和钛锆合金种植体表面形貌及表面特性研究
15
作者 常尧仁 徐方方 +3 位作者 李婕 游元和 刘纯 殷丽华 《中华口腔医学杂志》 CAS CSCD 北大核心 2019年第2期118-123,共6页
目的探讨亲水处理对纯钛和钛锆合金种植体表面形貌及表面特性的影响,为种植体表面改性研究提供参考。方法使用喷砂酸蚀或喷砂酸蚀+亲水处理的方法,制备纯钛组、亲水性纯钛组、钛锆合金组、亲水性钛锆合金组试件(每组11个)。通过表面接... 目的探讨亲水处理对纯钛和钛锆合金种植体表面形貌及表面特性的影响,为种植体表面改性研究提供参考。方法使用喷砂酸蚀或喷砂酸蚀+亲水处理的方法,制备纯钛组、亲水性纯钛组、钛锆合金组、亲水性钛锆合金组试件(每组11个)。通过表面接触角仪、扫描电镜、光学轮廓仪、原子力显微镜(atomic force microscope,AFM)以及拉曼光谱仪分析4组钛试件表面形貌及表面特性。结果亲水性纯钛及亲水性钛锆合金表面接触角分别为1.6°±0.3°和1.5°±0.2°,纯钛及钛锆合金表面接触角分别为101.4°±4.6°和96.2°±3.0°。扫描电镜显示纯钛及钛锆合金表面的纳米突起较少甚至缺如,亲水性纯钛及亲水性钛锆合金表面的纳米突起则相对较多;亲水性纯钛表面纳米突起直径小且相对密集,亲水性钛锆合金表面纳米突起直径大且相对分散。光学轮廓仪及AFM显示亲水性纯钛和亲水性钛锆合金表面粗糙度均显著大于纯钛及钛锆合金(P<0.05)。拉曼光谱分析可见纯钛组表面仅存在非结晶型TiO2,而另3组均可见金红石型TiO2特征峰,但表现为横向不均匀性,在拉曼位移610 cm-1后4组拉曼光谱相似。结论喷砂酸蚀+亲水处理可提高纯钛和钛锆合金的表面亲水性与表面粗糙度,提高纯钛和钛锆合金种植体的表面性能。 展开更多
关键词 合金 表面特性 牙种植体
A general strategy for the reliable joining of Al/Ti dissimilar alloys via ultrasonic assisted friction stir welding
16
作者 Zhongwei Ma Yanye Jin +3 位作者 Shude Ji Xiangchen Meng Lin Ma Qinghua Li 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第1期94-99,共6页
Ultrasonic assisted friction stir welding(UaFSW) was used to join 6061-T6 aluminum and Ti6Al4 V alloys.A small plunge depth endowed with the low heat input was used and the sound joints without obvious thickness reduc... Ultrasonic assisted friction stir welding(UaFSW) was used to join 6061-T6 aluminum and Ti6Al4 V alloys.A small plunge depth endowed with the low heat input was used and the sound joints without obvious thickness reduction were achieved. A diffusion-type bonding without the intermetallic compounds layer was observed at the joint interface. The ultrasonic improved the diffusion thickness and decreased the average size of grains and titanium alloy fragments. A hook-like structure was formed at the bottom interface of the UaFSW joint, which improved the bonding length and the mechanical interlocking. The microhardness of the stir zone was increased because of the further grain refinement induced by ultrasonic. The maximum tensile strength of the UaFSW joint was 236 MPa, which reached 85% of the base6061-T6 alloy. 展开更多
关键词 FRICTION STIR welding ULTRASONIC Aluminum/titanium alloys Microstructure Mechanical properties
Influence of Annealing Treatment on Microstructure Evolution and Mechanical Property of Friction Stir Weld AZ31 Mg Alloys
17
作者 LI Yajie QIN Fengming +3 位作者 LIU Cuirong LI Leijun ZHAO Xiaodong WU Zhisheng 《武汉理工大学学报:材料科学英文版》 SCIE EI CAS 2019年第2期417-425,共9页
In order to improve microstructure distribution and mechanical properties of Mg alloy joint by annealing treatment, die-casting AZ31 Mg alloy was successfully welded at rotation speed of 1 400 rpm and travel speed of ... In order to improve microstructure distribution and mechanical properties of Mg alloy joint by annealing treatment, die-casting AZ31 Mg alloy was successfully welded at rotation speed of 1 400 rpm and travel speed of 200 mm/min. The welded joints were annealed at 150-300 ℃ for 15-120 min and then were subjected to transverse tensile. The microstructure of annealed joints was analyzed by optical microscopy and electron backscatter diffraction. The experimental results indicate that(0001) texture intensity in stir zone significantly reduces and sharp transition of grain size is relieved in the interface between stir zone and thermo-mechanically affected zone after annealed at 200 ℃ for 30 min. Meanwhile, the elongation is increased from 7.5% to 13.0% and strength is increased slightly. It is because that annealing treatment can inhibit twin transformation and retain its ability to coordinate deformation during tensile deformation, which contributes to the improvement of plasticity. In addition, annealing treatment can increase the width of interfacial transition zone and lead to gradual transition of grain size between the SZ and TMAZ, which balances dislocation diffusion rate in different zone. 展开更多
关键词 magnesium alloys friction STIR welding annealing treatment texture distribution PLASTICITY
Wear Properties of Plasma Transferred Arc Fe-based Coatings Reinforced by Spherical WC Particles
18
作者 FAN Li DONG Yaohua +2 位作者 CHEN Haiyan DONG Lihua YIN Yansheng 《武汉理工大学学报:材料科学英文版》 SCIE EI CAS 2019年第2期433-439,共7页
Fe-based coatings reinforced by spherical WC particles were produced on the 304 stainless steel by plasma transferred arc(PTA) to enhance the surface wear properties. Three different Fe/WC composite powder mixtures co... Fe-based coatings reinforced by spherical WC particles were produced on the 304 stainless steel by plasma transferred arc(PTA) to enhance the surface wear properties. Three different Fe/WC composite powder mixtures containing 0 wt%, 30 wt%, and 60 wt% of WC were investigated. The microstructure and phase composition of the Fe/WC composite PTA coatings were evaluated systemically by using scanning electron microscope(SEM) and X-ray diffraction(XRD). The wear properties of the three fabricated PTA coatings were investigated on a BRUKER UMT TriboLab. The morphologies of the worn tracks and wear debris were characterized by using SEM and 3 D non-contract profiler. The experimental results reveal that the microhardness on the cross-section and the wear resistance of the fabricated coatings increase dramatically with the increasing adding WC contents. The coating containing 60 wt% of WC possesses excellent wear resistance validated by the lower coefficients of friction(COF), narrower and shallower wear tracks and smaller wear rate. In the pure Fe-based coating, the main wear mechanism is the combination of adhesion and oxidative wear. Adhesive and two-body abrasive wear are predominated in the coating containing 30 wt% of WC, whereas threebody abrasion wear mechanism is predominated in the coating containing 60 wt% of WC. 展开更多
关键词 plasma TRANSFERRED arc(PTA) metal matrix composite coatings(MMCs) SPHERICAL tungsten CARBIDE FE-BASED alloys WEAR resistance
Recent advances in biodegradation controls over Mg alloys for bone fracture management: A review
19
作者 Ming-Shi Song Rong-Chang Zeng +5 位作者 Yun-Fei Ding Rachel W.Li Mark Easton Ivan Cole Nick Birbilis Xiao-Bo Chen 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第4期535-544,共10页
Magnesium(Mg) alloys possess comparable physical and mechanical properties to bone, making them an outstanding candidate of implant materials for bone fracture treatment. In addition to the excellent biocompatibility,... Magnesium(Mg) alloys possess comparable physical and mechanical properties to bone, making them an outstanding candidate of implant materials for bone fracture treatment. In addition to the excellent biocompatibility, and bioactivity, the engagement of Mg alloys is key for a number of biological functionalities in the human body. The unique biodegradation nature of Mg alloy implants implies that it may not require a secondary removal procedure when the expected supporting tasks accomplish, as they may simply and safely 'disappear' over time. Nonetheless, the demonstrated drawback of potentially rapid degradation, is an issue that must be addressed appropriately for Mg implants and is consequently given unique attention in this review article. Herein, the critical criteria and the state-of-the-art strategies for controlling the degradation process of Mg alloys are reported. Furthermore, future developments of biodegradable Mg and its alloys systems with satisfactory specifications for clinical trials and deployment,are discussed. This review aims to provide information to materials scientists and clinical practitioners in the context of developing practical biodegradable Mg alloys. 展开更多
关键词 MAGNESIUM ALLOYS BIODEGRADATION Corrosion MECHANISMS CYTOCOMPATIBILITY
Effect of Partially Substituting Ca with Mischmetal on the Microstructure and Mechanical Properties of Extruded Mg-Al-Ca-Mn-Based Alloys
20
作者 Chao Xu Taiki Nakata +4 位作者 Guo-Hua Fan Kosuke Yamanaka Guang-Ze Tang Lin Geng Shigeharu Kamado 《金属学报:英文版》 SCIE EI CAS CSCD 2019年第2期205-217,共13页
Mg-2Al-1.2Ca-0.2Mn(at%)-based alloys with Ce-rich mischmetal(MM) substitution of 0–0.6 at% for Ca were hot extruded at 400 °C. The effect of MM substitution on the microstructure and mechanical properties of the... Mg-2Al-1.2Ca-0.2Mn(at%)-based alloys with Ce-rich mischmetal(MM) substitution of 0–0.6 at% for Ca were hot extruded at 400 °C. The effect of MM substitution on the microstructure and mechanical properties of the extruded alloys was investigated. The as-cast Mg-2Al-1.2Ca-0.2Mn alloy is mainly composed of a-Mg, Mg2Ca and(Mg,Al)2Ca phases and Al8Mn5 precipitates, whereas the substitution of MM brings about the formation of Al11MM3, Al2MM phases and Al10MM2Mn7 particles with the absence of (Mg,Al)2Ca phase. The volume fraction of MM-containing phases increases with increasing MM contents. All of the extruded alloys exhibit bimodal microstructure comprising fine dynamically recrystallized grains with almost random orientation and coarse deformed grains with strong basal texture. Dense nanosized planar Al2Ca and spherical Al–Mn phases precipitate inside the deformed grains. High tensile yield strengths of 350 MPa and moderate elongations to failure of >12% are obtained in all extruded alloys;the MM substitution induces negligible difference in the tensile properties at ambient temperature, while the highest MM substitution improves the strength at 180 °C due to the better thermal stability of the fragmented MM-containing phases. 展开更多
关键词 Magnesium ALLOYS EXTRUSION MICROSTRUCTURES Precipitation Mechanical properties
上一页 1 2 250 下一页 到第
使用帮助 返回顶部 意见反馈