Y. Q. Zhao
,
L. Zhou and J. Deng (Northwest Institute for Nonferrous Metal Research
,
P. O. Box 51 Xi' an
,
Shaanxi 710016
,
China)
金属学报(英文版)
Ti - 40 alloy is a single β phase burn resistant titanium alloy.Its high temperature deformation mech- anism is studied and its stress - strain curves are examined he use of Gleeble - 1500 thermal -simulator. The results reveal that there are abrupt flow stress drops followed b steady state.The magnitude of the flow stress drop increases with strain rote and decreases with temperature.Deformation activation energy, Q, is 247. 5 KJ/mol. The deformation mechanism of Ti - 40 alloy is controlled by the lattice diffusion Its constitutive equation is set up, i. e.
关键词:
burn resistant titanium alloy
,
null
,
null
,
null
高健
,
康健
,
吴学玲
,
徐競
,
李邦梅
,
邱冠周
中国有色金属学报
以分离于江西某铜矿的嗜铁钩端螺旋菌(L. ferriphilum YSK)菌株为研究对象,报道不同Fe2+浓度对 L. ferriphilum生长活性的影响.结果表明,YSK菌株生长最适宜的Fe2+浓度约为0.1 mol/L.当初始Fe2+浓度为0.4 mol/L时,进入对数生长期前很明显需要一个较长的延迟期,表明该Fe2+浓度对细胞的生长产生较强的抑制作用;当初始Fe2+浓度为0.6 mol/L时,YSK菌株的生长完全受到抑制.尽管高浓度的Fe2+抑制细胞的生长,但受到抑制而不生长繁殖的YSK细胞仍然具有氧化Fe2+的能力.
关键词:
L.ferriphilum YSK菌株
,
Fe2+
,
生长活性
MA Zongyi YAO Zhongkai Harbin Institute of Technology
,
Harbin
,
China
金属学报(英文版)
The SiC_w/Al composite prepared by squeeze casting has a combination of superior room temperature specific strength and modulus together with excellent thermal properties.The extrusion can make an improvement on the strength and ductility of the composite from 582 MPa as squeeze casted up to 639 MPa,and on the transformation from isotropic to the anisotropic structure.This seems to be explained by the orientation of whiskers and the densification of dislocations in matrix.TEM observation indicates that the stacking fault is the usual planar defect on the SiC_w surface. composite;;SiC whisker;;Al alloy;;microstructure
关键词:
composite
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null
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null
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null
Corrosion
This paper introduces the design of a localized corrosion rate monitoring instrument that can monitor and evaluate the maximum and stable localized corrosion rate of a nonpassivable metal in a corrosive environment by measuring the current density in a corrosion sensor with an occluded anode.
关键词:
instrument;localized corrosion rate;monitor
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
关键词:
room-temperature
Nabil S. Youssef
,
K.H.Hegab
材料科学技术（英文）
Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 were coordinated either in the enol or the keto form. IR spetra also showed that Fe(III)-, Ni(II)-, Mn(II)-, VO(II)-L1 and Cu(II)-L2 chelates behaved in a bidentate manner, in contrast with the two (1:1) M:L cobalt chelates with the two ligands are tridentate. TG analysis indicated the presence of three to twelve water molecules of hydration eliminated on heating up to 150°C and one or two coordinated water molecules removed at 150-180°C. The octahedral structure is proposed for all the chelates, except Cu(II)-L2 and Ni(II)-L1 chelates which have square planar geometry, based on their electronic spectra.
关键词:
