Marking Oxide Films on the Section of Al-XSi Alloys by Ultrasonic-vibration Treatment

Abstract

Oxide films entrapped in Al–XSi alloys with an X from 0% to 13% are different, and can be identified by the presented ultrasonic-vibration treatment. After polishing and ultrasonic-vibration treatment, the surfaces of samples or castings then show differently shaped foggy marks, including lumps, flakes, strips or spots. Oxide films fracture and particles become detached from the film during ultrasonic-vibration treatment. The polished surface thus becomes partly eroded after treatment, and these eroded areas are visibly as differently shaped foggy marks. This paper presents a sequential summary of the formation of these eroded areas, foggy marks, in samples of pure aluminum and Al–XSi alloys during ultrasonic-vibration treatment.