Precision Electrodischarge Machining of High Silicon P/M Aluminium Alloys for Electronic Application

2007 ◽  
pp. 243-247
Author(s):  
D. Biało ◽  
J. Perończyk ◽  
J. Tomasik ◽  
R. Konarski
Keyword(s):  
Aluminium Alloys ◽  
Electronic Application ◽  
Electrodischarge Machining ◽  
High Silicon

A Novel Micro-Arc Anodising Process for Aluminium Alloys Containing High Silicon

2009 ◽  
Vol 618-619 ◽  
pp. 279-282
Author(s):  
Zhi Ming Shi ◽  
Ming Xing Zhang
Keyword(s):  
Corrosion Resistance ◽  
High Voltage ◽  
Current Density ◽  
Aluminium Alloys ◽  
Al Alloys ◽  
Alkaline Electrolyte ◽  
Microstructure Examination ◽  
High Silicon ◽  
Highly Porous ◽  
Silicon Particles

Although the anodising process has been widely used in surface treatment of Al alloys, the well known sulphuric acid anodising process produces inhomogeneous and highly porous anodised coatings on Al alloys containing high Si due to the inertness of the silicon particles. The present work reports a novel micro-arc anodising process for such high-silicon aluminium alloys. Uniform and thick anodising coatings can be obtained through an anodising process in an alkaline electrolyte under high voltage and low current density conditions. The microstructure examination in SEM indicates that most pores in the coatings have been sealed during the anodising process, thus post-treatment that is normally needed for the currently used anodising process can be eliminated. The coating is very promising in the improvement of corrosion resistance for cast high-silicon aluminium alloys.

“Cavity” formation in superplastically deformed aluminium alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 958-959
Author(s):  
A. Cziráki ◽  
E. Ková-csetényi ◽  
T. Torma ◽  
T. Turmezey
Keyword(s):  
Grain Boundaries ◽  
Aluminium Alloys ◽  
Superplastic Deformation ◽  
Volume Fraction ◽  
Superplastic Forming ◽  
Polished Surface ◽  
Cavity Formation ◽  
Stress Concentrations ◽  
Electron Microscopic ◽  
Commercial Aluminium

It is known that the formation of cavities during superplastic deformation can be correlated with the development of stress concentrations at irregularities along grain boundaries such as particles, ledges and triple points. In commercial aluminium alloys Al-Fe-Si particles or other coarse constituents may play an important role in cavity formation.Cavity formation during superplastic deformation was studied by optical metallography and transmission scanning electron microscopic investigations on Al-Mg-Si and Al-Mg-Mn alloys. The structure of particles was characterized by selected area diffraction and X-ray micro analysis. The volume fraction of “voids” was determined on mechanically polished surface.It was found by electron microscopy that strongly deformed regions are formed during superplastic forming at grain boundaries and around coarse particles.According to electron diffraction measurements these areas consist of small micro crystallized regions. See Fig.l.Comparing the volume fraction and morphology of cavities found by optical microscopy a good correlation was established between that of micro crystalline regions.

EFFECT OF ADDITION OF THIRD ELEMENT IN HIGH SILICON-IRON ALLOY

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-133-C8-134
Author(s):  
H. Nakamura ◽  
N. Tsuya ◽  
Y. Saito ◽  
Y. Katsumata ◽  
Y. Harada
Keyword(s):  
Iron Alloy ◽  
Silicon Iron ◽  
High Silicon
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