Z.X. Yuan
,
S.H. Song
,
T.H. X.i
,
X.J. Zhangand Z.S. Yu(Department of Material
,
Wuhan Ye in University of Science and Technology
,
Wuhan 430081
,
China)(Department of Materials Physics
,
University of Science and Technology Beijing
,
Beijing 100083
,
China)
金属学报(英文版)
The infiuence of cerium on grnin boundaries of polycrpstalline N3Al alloys has beenstudied. The ja6mcability of a Ce-doped N3Al alloy strongly depends on the certumcontent. The alloy exhibits very poor fabrica6ility and cannot be fabrtcated into goodsheet8 by cold rolling when the concentmtion of cerium is <0. 0088wt% or>0.044wt%.A 0.011wt%Ce-doped N3Al alloy exhibits relatively good fabricability and may be fab-ricated into useful sheets by repeated cold rolling with 1OOa C annealing. The ductilityof the alloy strongly depends on the cerium distribution. Wthout the grain boundaryprecipitation of a second phase containing cer1um) the higher the segmpation level ofcerzum, the 6ettcr the tensile properties of the alloys, and in turn the more enhancedthe grain boundary cohesion.
关键词:
segregation
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QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
China
金属学报(英文版)
The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.
关键词:
stress corrosion cracking
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