JIANG Guang
,
WU Yinshun
,
LI Jiuqing
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LIU Haiping University of Science and Technology Beijing
,
Beijing
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China Department of Surface Sciences and Corrosion Engineering
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University of Science and Technology Beijing
,
Beijing 100083
,
China
金属学报(英文版)
Observation was carried out of the structure of sulphuric,oxalic or phosphoric film on Al after treatment of reanodizing and electrolytic depositing lubricant in (NH_4)_2MoS_4 solution,as well as of the deposited products by means of EMPA,TEM and energy spectro-scopic analysis.The deposited products are mixture of compounds of S and Mo rather than single MoS_2 and most of them dcposited near the surface layer of the film.Some regular long pores without barrier layer occurred in the film,but the regular fine channels without relation to the structural element parameters of original anodized film were found in the thickened barrier layer of phosphoric film.Sulphur may be remained as Mo sulphide in the film during heating under Ar protective environment.
关键词:
Al
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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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