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A novel heat-resistant Al–Si–Cu–Ni–Mg base material synergistically strengthened by Ni-rich intermetallics and nano-AlN_p microskeletons
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作者 Kaiqi Hu Qingfei Xu +3 位作者 Xia Ma Qianqian Sun Tong Gao Xiangfa Liu 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第3期306-312,共7页
In this work, nano-AlN particle(nano-AlN_p) microskeletons were introduced into an Al–Si–Cu–Ni–Mg alloy by Al–8 AlN master alloy in which the nano-AlN_p reinforcements connect with each other to form three-dimens... In this work, nano-AlN particle(nano-AlN_p) microskeletons were introduced into an Al–Si–Cu–Ni–Mg alloy by Al–8 AlN master alloy in which the nano-AlN_p reinforcements connect with each other to form three-dimensional networks. It is found that these nano-AlN_p microskeletons mainly distribute in the binary Al–Si eutectic zones resulting in flaky eutectic Si phases being modified to particulates. Meanwhile,the microskeletons strengthen the matrix synergistically with semi-continuous Ni-rich intermetallics in three dimensions. The tensile mechanical properties, micro-hardness and thermal expansion properties of the alloy at different temperatures are significantly improved. Especially, the ultimate tensile strength(UTS) at 350℃ increases from 85MPa to 106MPa, rising by 24.7%, which is ascribed to nano-AlN_p microskeletons assisting intermetallics with undertaking mechanical loading, and to the modification of eutectic Si phases to reduce the stress concentration at elevated temperatures. 展开更多
关键词 Al–Si ALLOY HEAT-RESISTANT AL ALLOY Mechanical properties at high temperatures Nano-AlN_p microskeletons
Microstructure, mechanical, and corrosion properties of extruded low-alloyedMg xZn 0.2Ca alloys 预览
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作者 Ying-zhong Ma Chang-lin Yang +4 位作者 Yun-jin Liu Fu-song Yuan Shan-shan Liang Hong-xiang Li Ji-shan Zhang 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第10期1274-1284,共11页
The microstructure, mechanical, and corrosion properties of extruded low-alloyed Mg xZn 0.2Ca (x 0, 1.0, 2.0, 3.0) alloys were investigated in this study. Findings from scanning electron microscope, X-ray diffraction ... The microstructure, mechanical, and corrosion properties of extruded low-alloyed Mg xZn 0.2Ca (x 0, 1.0, 2.0, 3.0) alloys were investigated in this study. Findings from scanning electron microscope, X-ray diffraction and transmission electron microscopy results indi- cate that the amount of ternary Ca2Mg6Zn3 phase, as the only secondary phase in 1.0Zn, 2.0Zn, and 3.0Zn alloys, gradually increases with the addition of Zn, while the Mg2Ca phase was observed in the Mg 0.2Ca alloy only. Zn has a strong effect on the orientation and intensity of textures, which also influence mechanical behaviors, as revealed by electron back-scatter diffraction. Among all the alloys, the Mg 2.0Zn 0.2Ca alloy obtains the maximum tensile strength (278 MPa) and yield strength (230 MPa). Moreover, Zn addition has an evi- dent influence on the corrosion properties of Mg xZn 0.2Ca alloy, and Mg 1.0Zn 0.2Ca alloy exhibits the minimum corrosion rate. This paper provides a novel low-alloyed magnesium alloy as a potential biodegradable material. 展开更多
关键词 magnesium alloy Mg Zn Ca alloy EXTRUSION MICROSTRUCTURE mechanical properties corrosion properties textures
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Effect of intermetallic compounds on the fracture behavior of dissimilarfriction stir welding joints of Mg and Al alloys 预览
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作者 Amir Hossein Baghdadi Zainuddin Sajuri +3 位作者 Nor Fazilah Mohamad Selamat Mohd Zaidi Omar Yukio Miyashita Amir Hossein Kokabi 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第10期1285-1298,共14页
Joining Mg to Al is challenging because of the deterioration of mechanical properties caused by the formation of intermetallic compounds (IMCs) at the Mg/Al interface. This study aims to improve the mechanical propert... Joining Mg to Al is challenging because of the deterioration of mechanical properties caused by the formation of intermetallic compounds (IMCs) at the Mg/Al interface. This study aims to improve the mechanical properties of welded samples by preventing the frac- ture location at the Mg/Al interface. Friction stir welding was performed to join Mg to Al at different rotational and travel speeds. The microstructure of the welded samples showed the IMCs layers containing Al12Mg17 (γ) and Al3Mg2 (β) at the welding zone with a thickness (< 3.5 m). Mechanical properties were mainly affected by the thickness of the IMCs, which was governed by welding parameters. The highest tensile strength was obtained at 600 r/min and 40 mm/min with a welding efficiency of 80%. The specimens could fracture along the boundary at the thermo-mechanically affected zone in the Mg side of the welded joint. 展开更多
关键词 aluminum alloy magnesium alloy intermetallic compounds dissimilar welded joint friction stir welding
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A brief review of brazing diamond in cutting tools 预览
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作者 崔冰 陶善仁 +2 位作者 薛行雁 钟素娟 徐东 《中国焊接:英文版》 EI CAS 2019年第2期56-64,共9页
Diamond has high hardness and good wear resistance.It is widely used in cutting tools and workpieces.Brazing is an effective method to realize high quality cemented carbide joints in various materials connection techn... Diamond has high hardness and good wear resistance.It is widely used in cutting tools and workpieces.Brazing is an effective method to realize high quality cemented carbide joints in various materials connection technologies.This paper analyzes the research status of diamond brazing in detail.The materials used as brazing filler in diamond brazing are reviewed.Copper base filler and nickel base filler are the most commonly used brazing filler in diamond brazing.The advantages and disadvantages of diamond grinding tools under different production methods are analyzed.In addition,a series of new brazing alloys such as amorphous Ni based brazing filler metals are analyzed.Finally,the development trend of diamond brazing is pointed out. 展开更多
关键词 brazing diamond manufacturing process filler alloy interface microstructure amorphous Ni-based filler alloy
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我国医用镍钛形状记忆合金标准现状分析 预览
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作者 汤京龙 马立翠 +5 位作者 温莉茵 徐红 宋可婧 吕原原 余新华 母瑞红 《中国药事》 CAS 2019年第6期649-654,共6页
目的:以完善镍钛形状记忆合金材料和植入物的安全有效性标准评价体系为目的,指明我国在该领域的标准化研究方向。方法:一方面,对比国内外在相关领域已发布的标准与相关材料产品安全有效性评价的标准需求之间的差距;另一方面,对比国内外... 目的:以完善镍钛形状记忆合金材料和植入物的安全有效性标准评价体系为目的,指明我国在该领域的标准化研究方向。方法:一方面,对比国内外在相关领域已发布的标准与相关材料产品安全有效性评价的标准需求之间的差距;另一方面,对比国内外标准在具体技术内容上的区别。通过对比总结出我国在此领域应该重点开展的标准化研究方向。结果:在医用镍钛形状记忆合金材料及其植入物领域,国际上已有美国等5个国家的标准化组织发布了25份专用标准,我国已发布了11份专用标准,基本形成了比较完善的标准体系。通过对国内外发布标准技术内容的比较,可发现我国在医用镍钛合金电偶腐蚀性能评价、相转变温度测试方法的标准相对滞后于国际标准。另外,通过分析对比镍钛形状记忆合金材料及其植入物安全有效性评价的标准需求,可发现在医用镍钛形状记忆合金材料或植入物体外镍离子释放、镍钛形状记忆合金植入物的形状恢复能力评价等方面,国内外均缺少规范的标准。结论:我国应在相关方面尽快开展标准化研究,积极缩小国内外标准差距,进一步完善镍钛合金材料和植入物的安全性和有效性标准评价体系,为企业的质量控制提供依据,为监管部门的技术审评提供指南,更好地保障人民群众的用械安全。 展开更多
关键词 镍钛 形状记忆 标准 合金
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Microstructural evolution and age-hardening behavior of quasicrystal-reinforced Mg-Dy-Zn alloy
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作者 Guang-Li Bi Yu-Xiang Han +3 位作者 Jing Jiang Chun-Hong Jiang Yuan-Dong Li Ying Ma 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第8期739-745,共7页
Microstructural evolution and age-hardening behavior of Mg-2 Dy-6 Zn(at%)alloy during solid-solution and aging treatment were investigated.The microstructure of as-cast alloy is composed of a-Mg,Mg3 DyZn6(Ⅰ)phase,Mg3... Microstructural evolution and age-hardening behavior of Mg-2 Dy-6 Zn(at%)alloy during solid-solution and aging treatment were investigated.The microstructure of as-cast alloy is composed of a-Mg,Mg3 DyZn6(Ⅰ)phase,Mg3 Dy2 Zn3(W)phase,Mg(Zn,Dy)phase and a small amount of Mg0.97Zn0.03 phases.After solid-solution treatment(480℃,12 h),all the I phases and most W phases dissolve into a-Mg matrix and the remainder W phases transform into Mg(Dy,Zn)phase and MgDy3 phase.During aging treatment,I phase and small amounts of W phases co-precipitate from α-Mg matrix,respectively.The alloy exhibits a peak hardness of HV 77.5 at 200 ℃ for 8 h.The excellent age-hardening behavior of alloy is mainly attributed to the co-precipitation strengthening of I and W phases. 展开更多
关键词 Mg-Dy-Zn ALLOY Microstructure I phase AGE-HARDENING BEHAVIOR
Preparation of Al-Zn-Mg-Cu alloy semisolid slurry through a water-cooled serpentine pouring channel
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作者 Wen-zhi Zhu Wei-min Mao +2 位作者 Qing-song Wei Chen Hui Yu-sheng Shi 《中国铸造:英文版》 SCIE 2019年第1期31-39,共9页
The semisolid slurry of Al-Zn-Mg-Cu alloy was prepared through a self-designed water-cooled copper serpentine pouring channel(WSPC) machine. Influences of pouring temperature, the number of turns and the cooling water... The semisolid slurry of Al-Zn-Mg-Cu alloy was prepared through a self-designed water-cooled copper serpentine pouring channel(WSPC) machine. Influences of pouring temperature, the number of turns and the cooling water flow rate on the microstructure of the semisolid Al-Zn-Mg-Cu alloy slurry were investigated. The results show that the semisolid Al-Zn-Mg-Cu alloy slurry with satisfactory quality can be generated by the WSPC when the pouring temperature is in the range between 680 ℃ and 700 ℃. At a given pouring temperature, the average grain size of primary α-Al decreases and the shape factor increases with the increase of the number of turns. When the cooling water flow rate is 450 L·h-1, the obtained semisolid slurry is optimal. During the preparation of the semisolid Al-Zn-Mg-Cu alloy slurry with low superheat pouring, the alloy melt has mixed inhibition and convection flow characteristics by 'self-stirring'. When the alloy melt flows through the serpentine channel, the chilling effect of the inner wall of the channel, the convection and mixed inhibition of the alloy melt greatly promote the heterogeneous nucleation and grain segregation. This effect destroys the dendrite growth mode under traditional solidification conditions, and the primary nuclei gradually evolve into spherical or nearspherical grains. 展开更多
关键词 Al-Zn-Mg-Cu Alloy SEMISOLID slurry WATER-COOLED SERPENTINE CHANNEL primary α-Al
一锅法制备三元ZnCdTe/ZnS量子点及其在照明中应用研究
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作者 刘久诚 魏娴 +3 位作者 魏畅 梅时良 谭振坤 张万路 《中国照明电器》 2019年第6期1-7,共7页
Cd系量子点由于其量子产率高,光谱调谐方便,成为世界各国科学家研究的热点;目前已经在生物荧光,传感,太阳能电池等领域有了很大的进展,但是Cd元素的毒性一直是限制其大规模应用的瓶颈。目前,降低含Cd量子点毒性的方法主要有两种:包覆保... Cd系量子点由于其量子产率高,光谱调谐方便,成为世界各国科学家研究的热点;目前已经在生物荧光,传感,太阳能电池等领域有了很大的进展,但是Cd元素的毒性一直是限制其大规模应用的瓶颈。目前,降低含Cd量子点毒性的方法主要有两种:包覆保护层和采用合金化。二元CdTe量子点的制备技术以及包覆技术已较为成熟,但是三元量子点的研究相对比较少,目前的制备技术大多比较复杂,成本较高,不适合规模化生产。本文采用溶剂热法,以巯基乙酸(TGA)作为稳定剂,通过包覆与合金化相结合的手段,成功在高温下制备了量子产率高,性能稳定,发射波长能够覆盖可见光区域的水溶性ZnCdTe量子点。 展开更多
关键词 三元量子点 合金 包覆 照明
Microstructure and properties of W-4.9Ni-2.1Fe heavy alloy with Dy2O3 addition
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作者 Yuan-Feng Xie Liang-Liang Zhou +3 位作者 Xiao-Yong Zhang Xiao-Xian Li Zeng-Lin Zhou Xue-Hui Zhang 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第8期746-753,共8页
The W-4.9 Ni-2.1 Fe-xDy2 O3 heavy alloy was fabricated by high-energy ball milling and spark plasma sintering(SPS)technique,and the microstructure,mechanical and friction behavior and anti-corrosion ability were inves... The W-4.9 Ni-2.1 Fe-xDy2 O3 heavy alloy was fabricated by high-energy ball milling and spark plasma sintering(SPS)technique,and the microstructure,mechanical and friction behavior and anti-corrosion ability were investigated by scanning electron microscope(SEM),Rockwell hardness tester,X-ray diffraction(XRD),reciprocating friction and wear tester,electrochemical station,etc.The results show that the trace Dy2 O3 particles,which mainly distributes in the W-M(tungsten-matrix)interface and the tungsten matrix phase,can dramatically decrease the tungsten grain size and the amount of O and P impurities aggregating in the interface,promote the γ-(Ni,Fe)bonding phase and tungsten particles uniform distribution,and increase the relative density,hardness,and wear and corrosion resistance properties.But the excessive Dy2 O3 addition can make the inhibition effect weaken,resulting in the decrease in the comprehensive performances of the alloy.So,the amount of Dy2 O3 should be appropriate.When the adding amount of Dy2 O3 particles is 0.7 wt%,the comprehensive performances of the heavy alloy are the best. 展开更多
关键词 DYSPROSIUM oxide W-4.9Ni-2.1Fe alloy Spark plasma SINTERING Mechanical property ANTICORROSION ability
Effect of vibration on seepage feeding during low-pressure casting of ZL205A alloy
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作者 Ru-jia Wang Shi-ping Wu Wei Chen 《中国铸造:英文版》 SCIE 2019年第1期40-45,共6页
Appropriate vibration can promote the feeding capacity of gravity casting, but the effect of vibration on the feeding of low-pressure casting is not clear. The effect of vibration on the seepage feeding of ZL205A allo... Appropriate vibration can promote the feeding capacity of gravity casting, but the effect of vibration on the feeding of low-pressure casting is not clear. The effect of vibration on the seepage feeding of ZL205A alloy was investigated by vibration casting experiment and physical simulation. The aqueous solution of sodium carboxymethyl cellulose(CMC) with the same rheological characteristic of metal melt was used. The results show that vibration can improve the feeding capacity and reduce shrinkage defects of ZL205A alloy in lowpressure casting. The orthogonal physical simulation experiments indicate that vibration with low frequency and great exerted force can significantly improve the seepage velocity of non-Newtonian fluid with solid particles in porous medium. The seepage phenomenon in CMC solution shows that vibration can change the structure of accumulated particles at the seepage entrance, and thus open the blocked feeding channel. The numerical simulation of one-dimensional semisolid fluid seepage reveals that vibration can form a wave field in the porous medium, which can reduce the adhesion force between fluid and capillary wall and destroy the boundary layer of fluid, and thus promote the seepage velocity. 展开更多
关键词 mechanical VIBRATION PHYSICAL simulation SEEPAGE ZL205A ALLOY
Design and motion testing of a Multiple SMA fin driven BIUV 预览
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作者 Yong-hua Zhang Jian-hui He Kinhuat Low 《水动力学研究与进展:英文版》 SCIE EI CSCD 2019年第1期124-136,共13页
Fishes interact with the fluid environment using various surfaces.These multiple control surfaces work in combination to produce the thrust and the balance torques in a steady swimming,to maneuver and to position them... Fishes interact with the fluid environment using various surfaces.These multiple control surfaces work in combination to produce the thrust and the balance torques in a steady swimming,to maneuver and to position themselves accurately even in turbulent flows.These motivate us to embark on a research program designed to develop an agile biologically inspired robotic fish based on the performance of multiple fins.To accomplish this goal,a mechanical ray-like fin actuated by the shape memory alloy (SMA) is developed,which can realize the oscillating motion,the undulating motion or even the complex three dimensional motion.The basic unit is the two opposite side SMA-driven plate,namely the fin ray.As a result,a lightweight bio-inspired fin is constructed by placing radially multiple SMA fin rays.A biologically inspired underwater vehicle (BIUV) is later built using the above multiple lightweight bio-inspired fins.Two common arrangement styles of multiple fins on the BIUV are considered here:one is the posterior fin (for the oscillating motion) that is parallel to the anterior fins (for the undulating motion),another one is the posterior fin that perpendicular to the anterior fins.The kinematic modeling,the deformation modeling and the detecting of the SMA fin are made.The thrust generation is also established.Finally,an experiment is conducted to test the performance of the proposed two arrangement styles,including the comparison of the averaged propulsion velocity and the averaged thrust under certain kinematic parameters.Meanwhile,the influence of the frequency and the amplitude of the SMA fin ray on the propulsion performance is also investigated. 展开更多
关键词 OSCILLATING undulating shape MEMORY alloy (SMA) biologically inspired UNDERWATER vehicle (BIUV) FIN RAY
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Single and double aging treatments on Mg97Zn1Y2 alloy
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作者 Di-qing Wan Ying-lin Hu +1 位作者 Hou-bin Wang Shu-ting Ye 《中国铸造:英文版》 SCIE 2019年第1期46-52,共7页
The development of magnesium alloys was limited due to the low absolute strength and poor corrosion resistance. It was found that the optimal performance could not be achieved in some alloys by a single quenching and ... The development of magnesium alloys was limited due to the low absolute strength and poor corrosion resistance. It was found that the optimal performance could not be achieved in some alloys by a single quenching and aging treatment, but could be achieved after a graded aging or multiple-stage aging heat treatment. The Mg97Zn1Y2 alloy was prepared and subjected to single and double aging treatments. Single aging was carried out at 250 ℃ for 6 to 15 h. For double aging, the first step was performed the same as the single aging. The second step was performed at 350 ℃ for 12 h. The microstructure and properties of the alloy with single and double aging were analyzed by means of hardness measurement, optical microscopy, scanning electron microscopy, X-ray diffraction, and polarization curve measurements. Results show that the precipitated nanoscale phases are formed during aging, and evenly distributed in the matrix. Compared with the single aging treatment, the hardness and corrosion resistance of the alloy are further improved due to the double aging treatment. 展开更多
关键词 SINGLE AGING DOUBLE AGING Mg97Zn1Y2 ALLOY LPSO PHASE
Effects of trace Cr on as-cast microstructure and microstructural evolution of semi-solid isothermal heat treatment ZC61 magnesium alloy
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作者 Xiao-feng Huang Ya-jie Ma +2 位作者 Qiao-qiao Zhang Lang-lang Wei Jian-qiao Yang 《中国铸造:英文版》 SCIE 2019年第1期53-62,共10页
The content and kind of trace elements in magnesium alloys have important effects on their ascast and semi-solid microstructures. In this research work, effects of trace Cr on as-cast and semi-solid microstructures of... The content and kind of trace elements in magnesium alloys have important effects on their ascast and semi-solid microstructures. In this research work, effects of trace Cr on as-cast and semi-solid microstructures of ZC61 magnesium alloy were investigated by metal mold casting and semi-solid isothermal heat treatment. The results show that the addition of Cr can refine the α-Mg phase without generating a new phase, noticeably change the eutectic phase, and decrease the average size of solid particles at the same isothermal heat treatment conditions. Non-dendritic microstructures of all alloys are constituted of α1-Mg phases, α2-Mg phases and eutectic phases after water quenching. With isothermal temperature increased or holding time prolonged, the eutectic microstructure(α-Mg+MgZn2+CuMgZn) at the grain boundaries in as-cast alloy is melted preferentially and then turned into semi-solid non-dendritic microstructure by processes of initial coarsening, microstructure separation, spheroidizing and final coarsening. Especially when the ZC61-0.1 Cr alloy was treated at 585 ℃ for 30 min, the ideal non-dendritic microstructure can be obtained, and the corresponding solid particle size and shape factor were 37.5 μm and 1.33, respectively. The coarsening process of solid α-Mg phase at higher temperature or longer time, which is affected by both combining growth and Ostwald ripening mechanism, is refrained when Cr is added to the ZC61 alloy. 展开更多
关键词 ZC61 magnesium alloy CR content SEMI-SOLID isothermal heat treatment NON-DENDRITIC microstructure MICROSTRUCTURAL evolution
Tunable Perpendicular Magnetic Anisotropy in Off-Stoichiometric Full-Heusler Alloy Co2MnAl
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作者 余之峰 鲁军 +5 位作者 王海龙 赵旭鹏 魏大海 马佳淋 毛思玮 赵建华 《中国物理快报:英文版》 SCIE CAS CSCD 2019年第6期79-82,共4页
Off-stoichiometric full-Heusler alloy Co2 MnAl thin films with different thicknesses are epitaxially grown on GaAs(001) substrates by molecular-beam epitaxy. The composition of the films, close to Co1.65Mn1.35Al(CMA),... Off-stoichiometric full-Heusler alloy Co2 MnAl thin films with different thicknesses are epitaxially grown on GaAs(001) substrates by molecular-beam epitaxy. The composition of the films, close to Co1.65Mn1.35Al(CMA),is determined by x-ray photoelectron spectroscopy and energy dispersive spectroscopy. Tunable perpendicular magnetic anisotropy(PMA) from 3.41 Merg/cm^3 to 1.88 Merg/cm^3 with the thickness increasing from 10 nm to 30 nm is found,attributed to the relaxation of residual compressive strain. Moreover, comparing with the ultrathin CoFeB/MgO used in the conventional perpendicular magnetic tunnel junction, the CMA electrode has a higher magnetic thermal stability with more volume involved. The PMA in CMA films is sustainable up to 300℃,compatible with semiconductor techniques. This work provides a possibility for the development of perpendicular magnetized full-Heusler compounds with high thermal stability and spin polarization. 展开更多
关键词 TUNABLE PERPENDICULAR Magnetic ANISOTROPY Full-Heusler Alloy Co2MnAl different thicknesses
Hot compression deformation behavior of biomedical Ni-Ti alloy
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作者 Zhen Wang Xiao-Wen Xu Bing Zhang 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第7期609-619,共11页
Biomedical Ti-55.78 (wt%) Ni alloy samples were prepared by vacuum induction melting, and their hot compression deformation behavior was studied in the deformation temperature range of 750-950℃, the strain rate range... Biomedical Ti-55.78 (wt%) Ni alloy samples were prepared by vacuum induction melting, and their hot compression deformation behavior was studied in the deformation temperature range of 750-950℃, the strain rate range of 0.001-1.000 s^-1 and the true strain range of 0.1 -0.7. The constitutive equation of the as-cast biomedical Ni-Ti alloy was established based on the Arrhenius constitutive model, and error analysis of the constitutive equation was carried out. The processing zone and unstable thermal deformation zone of the as-cast biomedical Ni-Ti alloy were obtained by establishing hot processing maps based on a dynamic material model. The results showed that deformation temperature and strain rate were the main factors affecting the flow stress. The results of error verification of the constitutive equation show that the predicted flow stress curves agree well with the measured ones. Therefore, the constitutive equation based on Arrhenius can accurately predict the high temperature flow stress of as-cast biomedical Ni-Ti alloy. The optimum parameters for forging process of biomedical Ni-Ti alloy are the strain rate less than 0.003 s^-1 and the hot deformation temperature range of 930-950℃. 展开更多
关键词 BIOMEDICAL NI-TI ALLOY HOT compression deformation Constitutive equation HOT processing map
Corrosion resistance of Mg(OH)2/Mg-Al-layered double hydroxide coatings on magnesium alloy AZ31: influence of hydrolysis degree of silane
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作者 Qing-Song Yao Zhong-Chao Li +5 位作者 Zai-Meng Qiu Fen Zhang Xiao-Bo Chen Dong-Chu Chen Shao-Kang Guan Rong-Chang Zeng 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第7期629-641,共13页
Mg(OH)2/Mg-Al-layered double hydroxide (LDH) coatings were modified with methyltrimethoxysilane (MTMS) on magnesium alloys. Effect of hydrolysis degree of silane solution on coating formation was investigated. Chemica... Mg(OH)2/Mg-Al-layered double hydroxide (LDH) coatings were modified with methyltrimethoxysilane (MTMS) on magnesium alloys. Effect of hydrolysis degree of silane solution on coating formation was investigated. Chemical compositions and surface morphologies of the coatings were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electronic microscopy (FESEM). Results indicated that the composite coatings consisted of polymethyltrimethoxysilane (PMTMS), LDH and Mg(OH)2. Electrochemical and hydrogen evolution measurements revealed that the composite coatings possessed good corrosion resistance, especially the ones prepared in a high hydrolysis degree of silane. The optimum corrosion resistance of the composite coati ng was LDH/PMTMS-3 coating, which had the lowest value of corrosion current density (5.537×10^-9 A·cm^-2) and a dense surface.Plausible mechanism for coating formation and corrosion process of MTMS-modified Mg(OH)2/Mg-Al-LDH coatings were discussed. 展开更多
关键词 Magnesium alloy Layered double HYDROXIDE (LDH) SILANE Coating Corrosion resistance
The microscopic mechanical performance for nonuniform welded joint of nickel-based alloy with nanoindentation 预览
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作者 李晓泉 郝本行 +2 位作者 陈一鑫 云叶菱 杨宗辉 《中国焊接:英文版》 EI CAS 2019年第2期29-34,共6页
To quantify the nonuniform micromechanical performance of welded joint,the load-displacement curves by nanoindentation test were introduced to examine different zones including base metal,coarse grained heat affected ... To quantify the nonuniform micromechanical performance of welded joint,the load-displacement curves by nanoindentation test were introduced to examine different zones including base metal,coarse grained heat affected zone,partially melted zone,weld metal near the fusion boundary and weld metal center.The results showed that the strengthening effect of weld metal was more obvious than that of heat affected zone for nickel based welded joint and especially in coarse grained heat affected zone,the hardening resulted from overheating was not apparent.Nickel based weld metal with high content of alloying elements which were often segregated at interdendritic regions or precipitated in grain interior under nonequilibrium solidification contributed to the characteristics that differ from conventional low alloy steel welded joint. 展开更多
关键词 microscopic mechanical performance NANOINDENTATION nickel based alloy welded joint
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Influence of Reaction Time on Growth Behaviours of Mg-Al LDH Films 预览
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作者 WU Liang CHEN Jing +5 位作者 ZHANG Sheng TANG Ai-tao YANG Dan-ni ZHANG Gen LIU Lei PAN Fu-sheng 《表面技术》 EI CAS CSCD 北大核心 2019年第3期19-26,共8页
Mg-Al LDH film was fabricated on anodized magnesium alloy AZ31 by in-situ growth method.The characteristics of the film were investigated by X-ray diffraction(XRD),Fourier transform infrared(FT-IR),scanning electron m... Mg-Al LDH film was fabricated on anodized magnesium alloy AZ31 by in-situ growth method.The characteristics of the film were investigated by X-ray diffraction(XRD),Fourier transform infrared(FT-IR),scanning electron microscopy(SEM)observation and electrochemical tests.The results showed that the crystallinity of LDH film was increased with reaction time.When the reaction time was more than 12 h,the LDH film had complete crystal layered structure.The anodic oxide film was sealed basically by the growth of LDH nanosheets after 6 h reaction.The corrosion resistance of the films became better with the increasing of reaction time.However,after 12 h reaction,the corrosion resistance of the film decreased.The formation behavior of the Mg-Al LDH film was proposed.That the competitive growth of LDH grains,which contains dissolution and recrystallization,was proposed to explain the change of the growth and corrosion resistance of the Mg-Al LDH film. 展开更多
关键词 magnesium alloy corrosion resistance in-situ GROWTH LAYERED double hydroxide(LDH) reaction time
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A promising new class of irradiation tolerant materials:Ti2ZrHfV0.5Mo0.2 high-entropy alloy
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作者 Yiping Lu Hefei Huang +9 位作者 Xuzhou Gao Cuilan Ren Jie Gao Huanzhi Zhang Shijian Zheng Qianqian Jin Yonghao Zhao Chenyang Lu Tongmin Wang Tingju Li 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第3期369-373,共5页
Recently, high-entropy alloys(HEAs) or multi-principal-element alloys with unprecedented physical,chemical, and mechanical properties, have been considered as candidate materials used in advanced reactors due to their... Recently, high-entropy alloys(HEAs) or multi-principal-element alloys with unprecedented physical,chemical, and mechanical properties, have been considered as candidate materials used in advanced reactors due to their promising irradiation resistant behavior. Here, we report a new single-phase bodycentered cubic(BCC) structured Ti2 ZrHfV0.5Mo0.2 HEA possessing excellent irradiation resistance, i.e.,scarcely irradiation hardening and abnormal lattice constant reduction after helium-ion irradiation,which is completely different from conventional alloys. This is the first time to report the abnormal XRD phenomenon of metallic alloys and almost no hardening after irradiation. These excellent properties make it to be a potential candidate material used as core components in next-generation nuclear reactors. The particular irradiation tolerance derives from high density lattice vacancies/defects. 展开更多
关键词 High-entropy alloy IRRADIATION resistance MICROSTRUCTURAL characterization DEFECTS evolution
Influence of solution treatment on microstructure, corrosion resistance, and oxidation behavior of cast G-NiCr28W alloy
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作者 Alptekin Kisasoz 《中国铸造:英文版》 SCIE 2019年第1期63-70,共8页
G-NiCr28W is a nickel-based cast alloy. Its microstructure consists of nickel-rich matrix phase and chromium-rich eutectic carbides. The solution treatment process can provide homogenous microstructure and desired mec... G-NiCr28W is a nickel-based cast alloy. Its microstructure consists of nickel-rich matrix phase and chromium-rich eutectic carbides. The solution treatment process can provide homogenous microstructure and desired mechanical/thermal properties for G-NiCr28W alloy. However, the solution treatment process affects the corrosion resistance of the alloy and it causes metal loss due to the occurrence of oxidation at atmospheric conditions. Therefore, determining the changes in the properties of the G-NiCr28W is important. For this purpose, G-NiCr28W specimens were solution treated at 1,040 ℃, 1,100 ℃ and 1,160 ℃ for 1 h and 8 h, respectively. The microstructures of the solution-treated samples were characterized by optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction analysis. Moreover, hardness, corrosion resistance and oxidation behaviors of the solution-treated samples were examined. The solution treatment process applied at 1,160 ℃ led to the formation of Fe2W2C blocky carbides, and hardness of the sample increased with the existence of blocky carbides, while corrosion resistance decreased. Furthermore, excessive metal loss occurred depending on oxidation due to the high process temperature at 1,160 ℃. 展开更多
关键词 G-NiCr28W nickel-based ALLOY heat treatment corrosion behaviour OXIDATION
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