Synchrotron radiation X-ray imaging of cavitation bubbles in Al–Cu alloy melt

•Cavitation was fist directly observed in non-transparent and high-melting alloy.•Synchrotron radiation X-ray imaging was exploited to study cavitation in metals.•The X-ray imaged “bubble” shows a near maximum radius of the oscillating bubble.•Cavitation bubble size obeys a truncated Gaussian distribution.

Cavitation bubbles in Al–10 wt.%Cu melt has been investigated by adopting synchrotron radiation X-ray imaging technology. In-situ observation reveals that most of bubbles concentrate within an intense cavitation zone nearby the radiation face. The measured near-maximum bubble radii obey a similar truncated Gaussian distribution as in water but increase by nearly the magnitude of one order due to higher ultrasonic intensity applied in aluminum melt.