刘元帅徐坚
金属学报
采用“3D法”, 系统地研究了Ti-(Cu1-xNix)-Sn(0.20≤x≤0.30, 原子分数, 下同) 四元合金的玻璃 形成能力对成分变化的依赖性. 确定玻璃形成能力最佳的合金为Ti38Cu37.8Ni16.2Sn8,Cu模吸铸形成金属玻璃 棒材的临界直径接近1 mm.该金属玻璃的过冷液态温度区间宽度ΔTx为56 K, 约化玻璃转变温度T rg为0.57. 对电弧熔炼Ti38Cu37.8Ni16.2Sn8合金微观结构的研究表明,合金熔体的凝固主要经历伪二元共晶反应:L→ Ti5Sn3Cu+TiCuNi.
关键词:
非晶态合金
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metallic glass
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eutectic reaction
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Ti alloy
Z.G.Liu
,
B.Gabbitas
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D.L.Zhang
,
J.Liang
,
W.Gao
材料科学技术（英文）
The production and microstructural characterization of two types of ceramic particulate reinforced Ti matrix composites (TMCs): Ti-6Al-4V/10~vol. pct TiB and Ti(Al,O)/58 vol. pct Al2O3 were studied. The Ti-6Al-4V/10 vol. pct TiB composite with refined microstructure has been produced using a combination of high energy mechanical milling and hot isostatic pressing. The Ti(Al,O)/58 vol. pct Al2O3 in-situ composite powder has been produced using a novel powder processing process which involves high energy mechanical milling of a mixture of Al and TiO2 powders to produce an Al/TiO2 composite powder followed by thermal treatment of the composite powder. The Ti(Al,O)/58 vol. pct Al2O3 composite powder has been used to produce coatings. Selected mechanical properties of the Ti-6Al-4V/10 vol. pct TiB composite and the high temperature oxidation resistance have also been evaluated.
关键词:
Ti alloy
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null
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null
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null
Z.M. Song
材料科学技术（英文）
Fatigue cracking behavior from a notch was investigated at room temperature for Ti–6.5Al–3.5Mo–1.5Zr–0.3Si (TC11) alloys with four different microstructures obtained at different cooling rates from the β transus temperature. It was found that the alloy with lamellar structures consisting of α/β lamellae or acicular α' martensite laths had a higher fatigue crack initiation threshold from the notch, while the bimodal structure with coarse α grain had a lower fatigue cracking resistance. The alloy with α/β lamellar structure showed a higher fatigue crack growth resistance. The length scales of the microstructures were characterized to correlate with fatigue cracking behavior. Fatigue cracking mechanism related to microstructures was discussed.
关键词:
Ti alloy
LIU Ping Institute of Aeronautical Material
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Beijing
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ChinaXU Changgan Beijing University of Aeronautics and Astronautics
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Beijing
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China XU Changgan
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Associate Professor
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Group 102
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Beijing University of Aeronautics and Astronautics
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37 Xueyuan Road
,
Beijing 100083
,
China
金属学报(英文版)
The electrochemical behaviour,which is presented by means of anodic polarization curves.of the component phases in Ti and Ti alloys in aqueous solutions of fluorhydrie acid,chhnhydric acid and amber acid has been investigated.The results indicate that the electrochemical behaviour of the allloys depends upon the composition and the lattice type.The corrosion of x and x′phase in actire region and that of β phase in passive region are the dominant corrosion behaviour.
关键词:
Ti alloy
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null
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null
Z. K. Yao
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H. Z. Cuo
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M. Wang
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F. Lan and P. F. Feng (Northwestern Polytechnical University
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Xi' an 710072
,
China)
金属学报(英文版)
Isothermal flashless die forging process of Ti - alloy structural air - frame part with varying thickness rib has been modelled in this paper.The results of present study show that a upside - down trapezoid rib would be formed and buckling would occure as blank is reduced,if the thickness of billet is maller than or equal to the thickness of rib. During modelling process of structural air frame part with E type cross - section rib, the saddle or lap would be formed finally at the middle of transverse rib between ribs with increase in deformation.If metal is allowed to flow out at confluence of longitudinal and transverse rib, the lop defect would be eliminated,, but a pipe cavity is obvious on corresponding loca- tion of blank. of defect formation depends on distance of metal flow ,friction,temperature homoge- neity of the blank and complexity of the part.
关键词:
Ti alloy
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null
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null
G.P.Li
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D.Li
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Y.Y.Liu
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S.X. Guan and Q.J.Wang (Department of Titanium Alloys
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Institute of Metal Research
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The Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
TEM examination proves that the second phase particle within the as-forged Ti-55alloy consists of either bright or dark "matrix" (nano-Nd3Sn) and some small dark blocks (SnO) dispersed in the "matrix". The HREM observation shows that the nanoNd3Sn phase is roughly spherical and about 3-15nm in diameter, and the grain boundaries with atout 1nm width are "gas-like" structure.
关键词:
Ti alloy
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null
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null
YU Bingxi GAO Shujun Institute of Metal Research
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Academia Sinica
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Shenyang
,
China
金属学报(英文版)
The variations of Debye temperature and lattice parameter of Ti-30Mo alloy with different hydrogen contents were measured by means of X-ray diffraction.It was found that as the hydrogen content increases,the Debye temperature decreases,but the lattice parameter of the aUoy increases.The above results experimentally support the decohesion theory that the in- crease of hydrogen in metals will weaken the cohesive force between the atoms and make met- als brittle.
关键词:
Debye temperature
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null
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null
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null
Y.L. Yang
金属学报(英文版)
The mixing technology of laser and heated nitrogen was applied to improve the surface hardness of titanium alloy (TC4). The samples were nitrided with laser power density of 6.5×105W·cm-2, the scanning speed various from 100 to 500mm·min-1. The nitrogen gas was pre-heated to 300℃ to accelerate the nitriding process. Some interested samples were tested with XRD method (X-ray diffraction) to analyze the composition of nitrides, and the surface hardness of HV was measured. The results show that TiN and Ti2N were formed on the surface of Ti alloy with proper nitriding parameters, but TiN is the main composition. The surface hardness increased by three times, which is from the original value of 269 to 794kg·mm-2. The mechanism of the mixing technology is considered mainly of the activation of nitrogen by laser power and the pre-heated process which accelerated the nitriding process. The nitridation process can be considered as six steps given in detail. The result by analyzing the mechanism of improving the surface property of TiAl alloy shows the improvement of surface property due to two factors: the first reason is the result of laser annealing, and the second one is the formation of TiN.
关键词:
laser nitridation
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表面硬度
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钛合金
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X射线衍射
