检索结果-南通市图书馆

Precipitation evolution and properties of Cu-15Ni-8Sn alloys via Al microalloying during ageing

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第10期43卷 5216-5228页

作者： Wei Luo li-jun peng Xu-jun Mi Hao-Feng Xie Yi-Cheng Cao Shu-Hui Huang State Key Laboratory of Nonferrous Metals and Processes GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute Co. Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China School of Materials Science and Engineering South China University of TechnologyGuangzhou 510640China

Studies have shown that microalloying Cu-Ni-Sn alloys using Al inhibits discontinuous precipitation reactions;however,the mechanism has not been investigated ***,this study explored the properties and precipitation evolution of Cu-15Ni-8Sn alloys without and with 1 wt%Al(Cu-15Ni-8Sn-1Al)during ageing at 500℃ through X-ray diffraction(XRD),scanning electron microscopy and high-angle annular dark-field scanning transmission electron *** results revealed that in Cu-15Ni-8Sn alloy,DO_(22)ordering first occurred after spinodal decomposition,subsequently transitioning to an L1_(2)ordering phase,during which the discontinuous precipitates gradually nucleated at the grain boundaries and formed *** alloy hardness increased sharply with ordering and then decreased rapidly after reaching its peak value,due to the dominance of the discontinuous precipitation ***,the DO_(22)ordered phase did not appear during the ageing of Cu-15Ni-8Sn-1Al alloy,and a Ni_(3)(Al_(x),Sn_(1-x))intermetallic compound with L1_(2)structure was formed,consuming Ni and Sn atoms,thereby significantly suppressing the discontinuous precipitation reaction and improving the stability during prolonged *** tensile strength(yield strength)of Cu-15Ni-8Sn and Cu-15Ni-8Sn-1Al alloys at peak hardness were 855(755)and 936 MPa(892 MPa),respectively,and their main strengthening mechanisms were solid solution strengthening and precipitation *** addition of 1 wt%Al effectively improved the precipitation strengthening effect of Cu-Ni-Sn alloys but severely decreased the ductility.

关键词： Cu-15Ni-8Sn Al addition Precipitation sequence Strengthening mechanism

Microstructure of phases in a Cu–Zr alloy

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2015年第10期34卷 706-709页

作者： li-jun peng Xu-jun Mi Bai-Qing Xiong Hao-Feng Xie Guo-Jie Huang State Key Laboratory of Nonferrous Metals and Processes General Research Institute for Nonferrous Metals

The morphology and crystallography of phases in the Cu-0.12% Zr alloy were investigated by scanning electron microscope(SEM), transmission electron microscope(TEM), and high-resolution transmission electron microscope(HRTEM). The results show that the as-cast microstructure of Cu–Zr alloy is mainly Cu matrix and eutectic structure which consist of Cu and Cu5Zr phases with a fine lamellar structure. The disk-shaped and plateliked Cu5Zr phases with fcc structure are found in the matrix, in which habit plane is parallel to {111}a plane of the *** the copper matrix and Cu5Zr phase,there exists an orientation relationship of [112]a|| [011]Cu5Zr;(111)a||(111)Cu5Zr. The space structure model of Cu5Zr phase can be established.

关键词： Cu–Zr alloy Microstructure Crystal structure Morph

Microstructure and properties of Cu-2.8Ni-0.6Si alloy

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2013年第3期32卷 228-233页

作者： Xiang-peng Xiao Bai-Qing Xiong Guo-Jie Huang Lei Cheng li-jun peng Qi-Ming liang State Key Laboratory for Fabrication and Processing of Nonferrous Metals General Research Institute for Nonferrous Metals China Nonferrous Metals Processing Technology Albetter Albronze Co. Ltd.

The phase transformation behavior and heat treatment response of Cu-2.8Ni-0.6Si （wt%） alloy sub- jected to different heat treatments were studied by X-ray diffraction, transmission electron microscopy observation, and measurement of hardness and electrical conductivity. The variation of hardness and electrical conductivity of the alloy was measured as a function of aging time. On aging at the temperature below TR （500-550 ℃） in Cu-2.8Ni-0.6Si alloy, the transformation undergoes spinodal decomposi- tion, DO22 ordering, and δ-NiaSi phase. On aging at the temperature above TR （500-550 ℃）, the transformation products were precipitations of 8-Ni2Si. The free energy versus composition curves were employed to explain the microstructure observations.

关键词： Microstructure Hardness Electricalconductivity Spinodal decomposition DO22 ordering

Interface evolution of Cu-Ni-Si/Al-Mg-Si clad composite wires after annealing

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2020年第12期39卷 1419-1424页

作者： Zhen Yang Xu-jun Mi Xue Feng Hao-Feng Xie li-jun peng Guo-Jie Huang Yan-Feng li Xiang-Qian Yin Key Laboratory of Nonferrous Metals and Processes GRIMAT Engineering Institute Co.LtdBeijing 101400China

Interface micros tructures of Cu-Ni-Si/Al-MgSi clad composite wires during isothermal annealing from 623 to 773 K were *** composite wires were fabricated by a drawing *** evolution of intermetallic compounds(IMCs)was analyzed.A continuous IMCs layer forms only after annealing for 1 min,which may be due to more IMCs nucleation points generated by deep drawing *** consist of Al_(4)Cu_(9),AlCu and Al_(2)Cu identified by energy-dispersive spectroscopy(EDS)and transmission electron microscopy(TEM).The growth activation energies of total IMCs,Al_(2)Cu,AlCu and Al_(4)Cu_(9),are 98.8,69.4,101.3 and 137.1 kJ·mol^(-1),*** higher growth activation energy of Al_(4)Cu_(9)results in the higher growth rate under high ***,the average interdiffusion coefficient for each IMC calculated by Wagner method shows that interdiffusion in Al_(2)Cu and AlCu is more active than that in Al_(4)Cu_(9).The higher growth rate of Al_(4)Cu_(9)may be caused by the long concentration range.

关键词： Intermetallic compounds Clad composite wires Diffusion Activation energy

Microstructure and properties of Cu-Ni-Si-Zr alloy after thermomechanical treatments

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2013年第2期32卷 144-149页

作者： Xiang-peng Xiao Bai-Qing Xiong Qiang-Song Wang Guo-liang Xie li-jun peng Guo-Xing Huang State Key Laboratory for Fabrication and Processing of Non-ferrous Metals General Research Institute for Nonferrous Metals Aluminum Corporation of China limited Luoyang Copper Co. Ltd.

The effect of thermomechanical treatments on the microstructures and properties of Cu-2.1Ni-0.5Si- 0.2Zr alloy was investigated. The hot-rolled plates were solution treated at 920 ℃ for 1.5 h, quenched into water, cold rolled by 70 % reduction in thickness, and then aged at 400, 450 and 500 ℃for various times. The variation in tensile strength and electrical conductivity of the alloy was measured as a function of the aging time. The results show the peak strength value of 665 MPa for the alloy aged at 450 ℃ for 2 h. However, the electrical conductivity is observed to reach a maximum of 47 % IACS aged at 450℃for 8 h. OM, SEM, and TEM were used for microstructural inspection of the alloy. Precipitation occurs preferentially at deformation bands in the cold-rolled alloy. Properties behavior is discussed in the light of microstructural features.

关键词： Cu-Ni-Si-Zr alloy Precipitation Electricalconductivity Tensile strength Microstructural features

Improving interface adhesion in TiNi wire/shape memory epoxy composites using carbon nanotubes

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2021年第4期40卷 934-938页

作者： Xue Feng li-Min Zhao Xu-jun Mi Guo-Jie Huang Hao-Feng Xie Xiang-Qian Yin li-jun peng Zhen Yang State Key Laboratory of Nonferrous Metals and Process General Research Institute for Nonferrous MetalsBeijing 100088China College of Materials Science and Engineering Liaocheng UniversityLiaocheng 252059China

In order to increase both the interfacial strength and interphase region strength between TiNi wires and shape memory epoxy,a novel interface structure including aminated CNTs was *** morphology shows that after electroplating and etching,continuous and homogeneous concave-convex layers form on the surface of astreated TiNi wires,meanwhile aminated CNTs were planted on the surface which could react with shape memory epoxy at the interface *** interfacial shear strength increases first with the CNT content rising but then a dramatic drop happens,and the maximum is obtained at CNT content of 0.6 g·L^(-1),which is about twice the result of acid etching TiNi wires.

关键词： Interfacial strength Interface structure Carbon nanotube Shape memory material Composite

Genetic Relation Analysis on Ramie[Boehmeria nivea(L.)Gaud.]Inbred lines by SRAP Markers

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2008年第8期7卷 944-949页

作者： liU li-jun peng Ding-xiang WANG Bo College of Plant Science and Technology Huazhong Agricultural University Wuhan 430070 P.R.China

The objective of this article is to reveal the variations of ramie inbred lines in DNA level and discuss their molecular background to provide a theoretical basis for ramie cross breeding. In the present study, the genetic relationships among 33 inbred line accessions and two wild types that originated from China and Brazil were estimated using sequence-related amplified polymorphism （SRAP） markers. The results showed that 33 out of 81 primer combinations turned out to be polymorphic and 332 polymorphism bands were obtained. On the basis of the appearance of the markers, the genetic relationships were analyzed using unweighted pair-group method of arithmetic average cluster analysis （UPGMA）, and the genetic Jaccard similarity coefficients were calculated. The inbred-lines originating from China and Brazil formed a cluster suggesting a possibility that the Brazilian cultivars could have developed from cultivars introduced from China. Within ramie inbred-lines, the groupings also indicated that the greatest genetic relationship among cultivars was correlated to the region of origin of cultivars. The results provided the evidence that SRAP was an efficient approach, suitable for taxonomic analysis of ramie inbred lines, To the authors＇ knowledge, this is the first application of SRAP marker on the systematics of ramie inbred lines.

关键词： relatives of ramie inbred lines SRAP taxonomic analysis UPGMA

Precipitation process and its effects on properties of aging Cu–Ni–Be alloy

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2013年第4期32卷 332-337页

作者： li-jun peng Bai-Qing Xiong Guo-liang Xie Qiang-Song Wang Song-Bai Hong State Key Laboratory of Nonferrous Metals & Process General Research Institute for Nonferrous Metals Yingtan Shine Electric Metal Material Co. Ltd

The precipitation process of aged Cu-Ni-Be alloy was investigated by X-ray diffraction （XRD）, trans- mission electron microscopy （TEM）, and high-resolution transmission electron microscopy （HRTEM）. The tensile strength, yield strength, and electronic conductivity of this alloy after aging were also studied. The precipitation sequence of the C17510 alloy aged at 525 ℃ is supersat-urated solid solution→G.P zones→ γ″-γ′→ γ. This transformation can be achieved by the accumulation of Be-atom layers. The G.P zones are composed of disk-shaped monolayers of Be atoms, which are formed on （001） matrix planes. The intermediate γ″ precipitate is nucleated in the G.P zones. The γ″ and γ′ precipitates have the same orientation relationship with matrix, e.g., （110）p｜｜（100）M,[001]p｜｜[001]M. The tensile strength of specimen shows a maximum during the aging process and then continuously decreases if the specimen is over aged. The strengthening effect of γ′ phase precipitated in aging at 525 ℃ for 4 h is calculated to be 436 MPa according to the Orowan strengthening, which is quite consistent with the experimental data.

关键词： Precipitation process C17510 alloy Metastable phases Strengthening mechanism

Properties and microstructure of copper–titanium alloys with magnesium additions

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 2290-2299页

作者： Lue Huang li-jun peng Jiang li Xu-jun Mi Gang Zhao Guo-Jie Huang Hao-Feng Xie Yi-Cheng Cao Wen-Jing Zhang Zhen Yang State Key Laboratory of Nonferrous Metals and Processes GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute Co. LtdBejing 101407China School of Materials Science and Engineering Northeastern UniversityShenyang110000China General Research Institute for Nonferrous Metals Beijing 100088China China Academy of Space Technology Beijing 100094China China Nonferrous Metals Mining Group(Tianjin)Co.Ltd Tianjin 3001llChina

The volume fractions and morphology of precipitates in precipitation-strengthened Cu-Ti alloys,which precipitate mainly as continuous and discontinuous precipitates,are important for the application of the *** study employed hardness and electrical conductivity tests transmission electron microscopy(TEM),atom probe tomography(APT),and first-principles calculations to demonstrate that the addition of Mg is effective for accelerating nanosized continuousβ'-Cu_(4)Ti precipitation as well as for suppressing the precipitation of coarse lamellar discontinuousβ-Cu_(4)Ti precipitates along the grain boundaries,resulting in Cu-Ti alloys with high yield strength and good electrical *** results showed that the continuous precipitation ofβ'-Cu_(4)Ti was accelerated by the Mg additions,which reduced the supersaturation of the matrix,thereby reducing the chemical driving force for the discontinuous *** the other hand,Mg additions increased the mismatch between the discontinuousβ-Cu_(4)Ti precipitates and matrix decreased the nucleation rate of the discontinuous precipitates,and increased the spacing of the discontinuous precipitation layer,resulting in a lower growth rate of the discontinuous ***,the addition of Mg to Cu-Ti alloys enhances the strength and improves the resistance to over-ageing.

关键词： Cu-Ti-Mg alloy Precipitation hardening Discontinuous precipitation Continuous precipitation Microstructure formation mechanism