Showing 2 results for R. Ebrahimi
S. A. Sajadi, R. Ebrahimi, M. M. Moshksar,
Volume 6, Issue 1 (winter 2009 2009)
Abstract
Abstract: In this paper, the forming process of a central hub by radial-forward extrusion is analyzed by using the finite
element software, ABAQUS. Radial-forward extrusion is used to produce hollow parts that generally feature a central
hub with radial protrusions. Effective design factors such as mandrel diameter, die corner radius, die fillet radius,
mandrel corner radius, tube wall thickness and frictional conditions on the force required are investigated by
simulation process. Commercially pure Aluminum AA1100 is selected as a model material for both experimental
investigation and simulation analysis. Comparison is made and good agreement between the experimental result and
that of finite element method is achieved.
A. Davoodi, J. Pan,ch. Leygraf, Gh. R. Ebrahimi, M. Javidani,
Volume 6, Issue 3 (Summer 2009 2009)
Abstract
Abstract: Localized corrosion of aluminum alloys is often triggered by intermetallic particles, IMP’s. To understandthe role of IMP’s in corrosion initiation of EN AW-3003, efforts were made to combine nano-scale ex-situ analysis ofthe IMP’s by SEM-EDS, SKPFM and in-situ AFM monitoring of the localized attack in chloride containing solution.The results showed that two distinct types of eutectically-formed constituent IMP’s exist the -Al(Mn,Fe)Si and theAl(Mn,Fe) phases. However, the exact chemical composition of the IMP’s varies with the particles size. Volta potentialdifference of surface constituents revealed that IMP’s have a higher Volta potential compared to the matrix, indicatingthe cathodic characteristic of the IMP’s. Noticeably, the boundary regions between the matrix and IMP’s exhibited aminimum Volta potential probably the sites for corrosion initiation. Localized corrosion attack monitored by in-situAFM clearly showed the trench formation occurrence around the large elongated IMP’s in the rolling direction.
