Ultrafast synchrotron X-ray imaging studies of microstructure fragmentation in solidification under ultrasound

Microstructures and properties of in-situ (ZrB2 + Al2O3)np/AA6111 composites synthesized under magnetic and ultrasonic fields

“…More importantly, the bubble fragments produced by implosion bubbles can be used as the bubble nuclei of the next bubble evolution cycle. The cyclic fatigue effect caused by the momentum of the oscillating bubble and the sound wave flow is the main mechanism for breaking up the solidified phase at the liquid-solid interface [29]. Besides, the acoustic enhanced flow contributes to break up the solid flow or redistribute it back to the bulk liquid or semi-solid melt, restraining the sedimentation of particles and promoting grain rounding.…”

Understanding the Highly Dynamic Phenomena in Ultrasonic Melt Processing by Ultrafast Synchrotron X-ray Imaging

“…These investigations provide valuable visual data for understanding the effects of USP. Generally, organic transparent alloys and solutions are very different from liquid metal alloys in terms of density, viscosity, surface tension, heat/mass transfer coefficient and sound velocity; and it is inappropriate to simply apply all findings from organic alloy systems to metallic systems as argued by Wang et al [6].…”

“…In this paper, we presented three important cases obtained from systematic in situ and real-time studies carried out in the past 8 years or so. The experiments were conducted via close collaborations with scientists of the Advanced Photon Source (APS), USA, the Diamond Light Source (DLS), UK, Synchrotron SOLEIL, France, and Swiss Light Source (SLS), Switzerland; more and systematic results have been published in [6][7][8][9][10]. The experimental observations and interpretations were complemented by modelling and simulation using Helmholtz equation for calculating the propagation of acoustic pressure in liquid metal; and the Gilmore model for calculating the pressure and velocity at the oscillating ultrasonic bubble wall [6][7][8]10].…”

“…The experimental observations and interpretations were complemented by modelling and simulation using Helmholtz equation for calculating the propagation of acoustic pressure in liquid metal; and the Gilmore model for calculating the pressure and velocity at the oscillating ultrasonic bubble wall [6][7][8]10]. Figure 1 shows the experimental apparatus and the setup at the 32-ID-B of APS [6]. The sample holder was made from a quartz tube with a flat thin channel region (15 x 10 0.30 mm) in the middle that can be filled with *300 lm thick liquid metal.…”

Non-destructive testing and evaluation of composite materials/structures: A state-of-the-art review

“…Second-generation synchrotrons were dedicated to the production of synchrotron light in the 1980s, which used bending magnets to generate synchrotron light. Third-generation light sources originated in the 1990s [221], with facilities that used insertion devices (wigglers and undulators) to produce intense and tuneable X-ray beams. Fourth-generation facilities will be based on free electron lasers which offer more advanced capabilities to generate brighter light sources [222].…”