| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Light Metal Technology
|
| Presentation Title |
Revealing Growth Mechanisms of Faceted Al2Cu Intermetallic Compounds via High-speed Synchrotron X-ray Tomography |
| Author(s) |
Zihan Song, Oxana V. Magdysyuk, Tay Sparks, Yu-Lung Chiu, Biao Cai |
| On-Site Speaker (Planned) |
Zihan Song |
| Abstract Scope |
High-speed synchrotron X-ray tomography to image the growth of Al2Cu intermetallic compounds in 4D (3D plus time) during solidification of Al-45wt%Cu alloy. Two categories of growth patterns (basic units and dendrites) are identified. Basic units are elongated rods whose cross-section are L, U or hollow-rectangular shapes. The transition from L pattern to U and finally to hollow-rectangular shaped morphology was observed. Faceted dendritic patterns include equiaxed prism and columnar dendrites. Self-repeated layer-by-layer stacking of the basic units is proposed as a governing mechanism for the growth of Al2Cu faceted dendrites. Furthermore, when rotating Al-45wt%Cu during upwards directional solidification, under a transverse magnetic field of 0.5T, highly refined and well aligned Al2Cu intermetallic compounds are obtained. This is attributed to a rotational stirring flow that modulates and regulates the temperature and solute distribution. The developed experimental findings provide a physical understanding of the formation of faceted intermetallic compounds during solidification. |