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Al_2O_3-(Co,Ni)陶瓷基复合材料的燃烧合成控制与组织

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特种铸造及有色合金 2008年第S1期28卷 334-337页

作者：陆韬潘冶东南大学材料科学与工程学院江苏省先进金属材料高技术研究重点实验室

用燃烧合成技术制备了Al2O3-(Co,Ni)陶瓷基复合材料,通过Al-CoO和Al-NiO的燃烧合成反应的热力学计算,提出了合适的反应体系成分设计原则。合理选择稀释剂配比,配合助燃体系及聚合物添加剂辅助反应,控制燃烧合成反应的剧烈程度,获得燃烧... 详细信息

用燃烧合成技术制备了Al2O3-(Co,Ni)陶瓷基复合材料,通过Al-CoO和Al-NiO的燃烧合成反应的热力学计算,提出了合适的反应体系成分设计原则。合理选择稀释剂配比,配合助燃体系及聚合物添加剂辅助反应,控制燃烧合成反应的剧烈程度,获得燃烧合成样品。结果表明,稀释剂能降低体系的反应绝热温度,通过合理的反应成分设计及反应控制,能得到金属合金相在陶瓷基体中颗粒尺寸细小、分布均匀的复合组织,运用合理的加压致密化技术提高试样相对致密度,得到致密试样。

关键词：陶瓷基复合材料燃烧合成成分设计

Investigation on the 773 K isothermal section of La-Fe-Sn ternary systems by X-ray powder diffraction

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Rare Metals 2010年第6期29卷 567-571页

作者： CHEN Xiang ZHUANG Yinghong CHEN Yungui key laboratory of Nonferrous Metal and New Processing Technology of materials (Ministry of Education of china) Guangxi University Nanning 530004 China Department of Physics and Electronic Information Engineering Neijiang Teachers College Neijiang 641002 China Department of metallic materials Engineering Sichuan University Chengdu 610065 China

The 773 K isothermal section of the La-Fe-Sn ternary system was investigated and constructed by X-ray powder diffraction（XRD）.The existence of two reported ternary intermetallic compounds,La6Fe13Sn and La3FeSn6,is confirmed in this *** with other R-Fe-Sn phase diagrams（R = Pr and Sm）,the binary alloys Fe3Sn and Fe5Sn3 are not *** compound Fe3Sn2 was observed from the XRD pattern of Fe3Sn2 samples,but it is not an equilibrium phase at 773 K and decomposes into Fe and FeSn phases completely for a longer heat treated *** to now,the crystal structure data of La2Sn3 has not been reported,so the X-ray pattern of La2Sn3 was only *** phase relationship for this compound was drawn by a dotted line.

关键词： intermetallics quenching phase diagrams X-ray diffraction.

Preparation of multi-walled carbon nanotube-reinforced TiNi matrix composites from elemental powders by spark plasma sintering

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Rare Metals 2012年第1期31卷 48-50页

作者： CAI Wei,FENG Xue,and SUI Jiehe National key laboratory Precision Hot Processing of Metals,School of materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,china National key laboratory Precision Hot Processing of Metals School of Materials Science and Engineering Harbin Institute of Technology Harbin China

Carbon nanotube (CNT)-reinforced TiNi matrix composites were synthesized by spark plasma sintering (SPS) employing elemental *** phase structure,morphology and transformation behaviors were *** was found that thermoelastic martensitic transformation be-haviors could be observed from the samples sintered above 800 ℃ even with a short sintering time (5min),and the transformation tempera-tures gradually increased with increasing sintering temperature because of more Ti-rich TiNi phase *** decreasing the sin-tering temperature and time to 700 ℃ and 5min could not protect defective MWCNTs from reacting with Ti,still-perfect MWCNTs re-mained in the specimens sintered at 900 ℃.This method is expected to supply a basis for preparing CNT-reinforced TiNi composites.

关键词： metallic composites shape memory materials carbon nanotubes spark plasma sintering

Effect of cooling rate on plastic deformation of Zr-based bulk metallic glasses

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Progress in Natural Science:materials International 2012年第1期22卷 21-25页

作者： Chunyan Li a,Shengzhong Kou a,b,Yanchun Zhao a,Guangqiao Liu b,Yutian Ding a a State key laboratory of Gansu advanced Non-ferrous Metal materials,Lanzhou University of Technology,Lanzhou 730050,china b key laboratory of Non-ferrous Metal Alloys and Processing of the Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,china [a] State key laboratory of Gansu advanced Non-ferrous Metal materials Lanzhou University of Technology Lanzhou 730050 China [b] key laboratory of Non-ferrous Metal Alloys and Processing of the Ministry of Education Lanzhou University of Technology Lanzhou 730050 China

The effect of cooling rate on plastic deformation of Zr-based bulk metallic glasses has been *** specimens with the diameters of 3 mm,4 mm and 6 mm cut from the same ladder-shaped Zr 55 Al 10 Ni 5 Cu 30 BMG rod were used in the present *** experimental results indicated that the different plastic strains were induced for the three type compression *** compressive plastic strain increased with the decreasing diameter for the as-cast specimens,which means that the compressive plastic strain increased with the increasing cooling *** reason of the difference is attributed to the free volume existed in the BMGs during the rapid solidification,and the larger free volume was contained in the specimen fabricated with the higher cooling *** has been found that the prominent serrations and multiple shear bands appeared during the compressive deformation tests of the specimen with smaller diameter of 3 mm,indicating that the specimen with smaller diameter exhibits better plasticity due to more free volume content.

关键词： Bulk metallic glasses Cooling rate Serration Plastic deformation Free volume

Plastic deformation behavior of Fe_(40)Ni_(40)P_(14)B_6 bulk metallic glass investigated by nanoindentation

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International Journal of Minerals,Metallurgy and materials 2007年第S1期15卷 68-72页

作者： Changqing Zhang and Kefu Yao key laboratory for advanced Manufacturing by materials Processing Technology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, china

Fe40Ni40P14B6 bulk metallic glass rods have been prepared by water quenching the fluxed alloy. The deformation behavior was investigated by nanoindentation tests and compressing tests. The average hardness and elastic modulus of the as-prepared Fe40Ni40P14B6 BMG (bulk metallic glass) measured by nanoindentation tests are 8.347 and 176.61 GPa respectively. The displace- ment-load curve shows “pop-in” characteristics which correspond to the loading rate bursts. Many shear bands around the indent were observed. The as-prepared Fe-based BMG exhibits a compressive plastic strain of 5.21%, which is much larger than that of other Fe-based glassy alloys and most of other BMGs.

关键词： Fe40Ni40P14B6 bulk metallic glass nanoindentation tests compressing tests, "pop-in" characteristics, shear bands, com- pressive plastic strain

Structural relaxation of metallic glass forming melts

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Science china(Physics,Mechanics & Astronomy) 2010年第3期53卷 405-408页

作者： BIAN XiuFang, QIN JingYu & QIN XuBo key laboratory for Liquid-Solid Structural Evolution and Processing of materials (Ministry of Education), Shandong University, Jinan 250061, china 1. key laboratory for Liquid-Solid Structural Evolution and Processing of materials (Ministry of Education) Shandong University Jinan 250061 China

The fragility of superheated melts, M, for 13 kinds of metallic alloys has been evaluated from the data of the dynamic viscosity above their liquidus temperatures. The authors find that the glass forming ability of metallic melts depends on the fragility of superheated melts rather than on the value of viscosity. In the present work the value of fragility is less than 1 for good glass-forming melts but more than 1 for the other melts. The variation rate of atomic coordination number with temperature indicates clearly the relaxation rate of molten structures. The fragility of superheated melts is found in good agreement with the variation rate of the atomic coordination number with temperature.

关键词： structural relaxation metallic glasses melts

ULTRASONIC SEPARATION OF MICRO-SIZED INCLUSIONS IN MOLTEN METAL

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Acta Metallurgica Sinica(English Letters) 2001年第5期14卷 375-379页

作者： X.Q. Bai and J.C. He key laboratory of National Education Ministry for Electromagnetic Processing of materials, Northeastern University, Shenyang 110004, china key laboratory of National Education Ministry for Electromagnetic Processing of materials Northeastern University

The coagulation time and position of micro-sized non-metallic inclusions in molten metal during ultrasonic separation process were investigated, and the motion course of micro-sized non-metallic inclusions in an ultrasonic standing wave field was numerically simulated. The results of theoretical analysis and numerical simulation show that the movement of inclusions depends on the balance between the acoustic radiation force, effective buoyancy force and viscous drag force. It is presented that micro-sized inclusions, agglomerated at antinode-planes may be removed further with horizon tal ultrasound.``

关键词： ultrasound molten metal micro-sized non-metallic inclusion numerical simulation process parameter

Effect of the cooling rate on plastic deformability of a Zr-based bulk metallic glass

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Science china(Physics,Mechanics & Astronomy) 2010年第3期53卷 415-418页

作者： ZHANG Jing, PANG ShuJie & ZHANG Tao key laboratory of Aerospace materials and Performance (Ministry of Education), Department of materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191, china 1. key laboratory of Aerospace materials and Performance (Ministry of Education) Department of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100191 China

The present work found the plastic deformability of Zr65Cu17.5Ni10Al7.5 BMG dependent on the cooling rate during the formation from the molten state alloy. The deformation behavior in the compression test of φ 2 mm Zr65Cu17.5Ni10Al7.5 BMGs as-cast or lathed from different sizes as-cast samples was characterized, and they exhibited different plastic strains. The compressive plastic strain increases with the decreasing diameter of the as-cast specimens, i.e. with increasing the cooling rate. It is suggested that free volume content in the BMGs, which is related to the cooling rate during the rapid solidification, could play an important role in the deformation process of the BMGs.

关键词： cooling rate shear band serration bulk metallic glass

Microstructure of Cu_(60)Zr_(20)Ti_(20) bulk metallic glass rolled at different strain rates

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Science china(Physics,Mechanics & Astronomy) 2008年第4期51卷 394-399页

作者： LI JinFu,CAO QingPing & ZHOU YaoHe State key laboratory of Metal Matrix Composites,School of materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200030,china State key laboratory of Metal Matrix Composites School of Materials Science Engineering Shanghai Jiao Tong University Shanghai 200030 China

The structural evolution of Cu60Zr20Ti20 bulk metallic glass during rolling at different strain rates and cryogenic temperature was investigated by X-ray diffraction (XRD),differential scanning calorimetry (DSC) and high-resolution transmission electron microscopy (HRTEM). It is revealed that the deformation-induced transformation is strongly dependent on the strain rate. At the lowest experimental strain rate of 1.0×10-4 s-1,no phase transformation occurs until the highest deformation degree reaches 95%. In a strain rate range of 5.0×10-4-5.0×10-2 s-1,phase separation oc-curs in a high deformation degree. As the strain rate reaches 5.0×10-1 s-1,phase separation and nanocrystallization concur. The critical deformation degree for oc-currence of phase transformation decreases with the strain rate increasing.

关键词： metallic glass inhomogeneous deformation strain rate phase separation nanocrystallization