Y. Zhou
,
C.S. Yang
,
J.A. Chen
,
G.F. Ding
,
L. Wang
,
M.J. Wang
,
Y.M. Zhang
,
T.H. Zhang
金属学报(英文版)
Microbridge testing is used to measure the Young's modulus and residual stresses of
metallic films. Nickel film microbridges with widths of several hundred microns are
fabricated by Microelectromechanical Systems. In order to measure the mechanical
properties of nickel film microbridges, special shaft structure is designed to solve the
problem of getting the load-deflection curves of metal film microbridge by Nanoindenter XP system with normal Berkovich probe. Theoretical analysis of the microbridge load-deflection curve is proposed to evaluate the Young's modulus and residual
stress of the films simultaneously. The calculated results based on the experimental
measurements show that the average Young's modulus and residual stress are around
190GPa and 175MPa respectively, while the Young's modulus measured by Nano-
hardness method on nickel film with silicon substrate is 186.8±7.34GPa.
关键词:
nickel film microbridge
,
null
,
null
,
null
Z.W. Yu
,
L. Wang
,
X.L. Xu
,
J.B. Qiang
金属学报(英文版)
The growth process of low-temperature plasma-nitriding layer was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The layer is composed
of expanded fcc phase (γN), whose lattice parameter of the layer increases with process
time resulting from increasing the nitrogen content. The layer hardness increases gradually with nitrogen content. The high slip band density on the layer surface observed
in situ by SEM shows that the surface yield occurs when supersaturated nitrogen content in the layer attains to some value, which is also responsible for the increase in
layer hardness.
关键词:
austenitic stainless steel
,
null
,
null
X.L. Xu
,
L. Wang
,
Z. W. Yu and Z.K. Hei(Institute of Metal and Technology
,
Dalian Maritime University
,
Dalian 116024
,
China)
金属学报(英文版)
The cross-sectional microstructure of an ion-nitrided layer on a No.45 steel was studied by transmission electron microscopy (TEM). The results show that the columnar crystals constitute the compound layer. Most of them have the microstructure of alternating ε-Fe2-3N and γ-Fe4N and others are single ε-Fe2-3N phase. There are abnormal strip ferrites between the columnar crystals. The transition layer mainly consists of spherical γ-Fe4N and cementite (Fe3C) particles in the pearlite are dissolved in this layer. In diffusion layer, besides the equilibrium phase γ-Fe4N, there are α -Fe16N2 and the satellite spots around main spots of α-Fe16N2 demonstrate its modulation structure. A metastable ordered cluster zone of the nitropen atoms was found in the division layer.
关键词:
ion nitriding
,
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
