Characterization of cast AlSi(Cu) alloys by scanning Kelvin probe force microscopy

• Published in: Electrochimica acta Vol. 51; no. 26; pp. 5892 - 5896
• Main Authors: Fratila-Apachitei, L.E., Apachitei, I., Duszczyk, J.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15.08.2006; Elsevier
• Subjects: Aluminum casting alloys; Applied sciences; Exact sciences and technology; Hardness; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Nobility; Particles; SKPFM; Volta potential; Volta potential; SKPFM; Particles; Nobility; Aluminum casting alloys; Eutectic alloy; Scanning probe microscopy; Mechanical properties; Kelvin probe; Aluminium alloy; Cast alloy; Surface structure; Corrosion resistance; Surface hardness; Wear resistance
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2006.03.027

The aluminum cast alloys undergo surface treatments involving micro-electrochemistry for improved hardness, wear and/or corrosion resistance. The susceptibility to local galvanic coupling for three different permanent mold cast aluminum alloys, i.e. 99.8 wt.%Al, Al–10 wt.%Si and Al–10 wt.%Si–3 wt.%Cu was investigated using the scanning Kelvin probe force microscopy (SKPFM) technique. All the particles detected in the alloys (i.e. Al–Fe, Al–Fe–Si, Si, Al 2Cu) revealed a positive Volta potential difference relative to the matrix. However, the nobility depended on particles composition. The highest Volta potential differences were determined in the Al–10 wt.%Si–3 wt.%Cu alloy between the copper containing intermetallics and the aluminum matrix whereas the lowest differences were detected for the Al–Fe particles in the 99.80 wt.%Al specimen. Further, the matrix of the 99.8 wt.%Al specimen showed Volta potential differences possibly due to compositional gradients following casting.