Solidification paths of Al-Cu-Sn alloys: comparison of thermodynamic analyses and solidification experiments using in situ X-radiography

Author : Hadjer Soltani, Wafa Boumechta, Sarah De Albuquerque, Guillaume Reinhart, Henri Nguyen-Thi , Danielle Cristina Camilo Magalhaes, Jose Eduardo Spinelli

Abstract :The Al-Cu-Sn alloys represent a new candidate material for the self-lubricating bearings manufacturing in the automotive industry. The addition of Sn to the Al-Cu binary alloy modified the solidification path of the ternary alloys and thus its microstructure. In this study, the solidification paths of Al-10 wt.% Cu-X wt.% Sn (with X = 0; 5; 10 and 20) alloys were investigated using three complementary approaches, namely: Thermo-Calc calculations, DSC (Differential Scanning Calorimetry) thermal analysis, and directional solidification experiments with in situ and real-time X radiography were conducted to gain insight into the liquid phase separation dynamic. The qualitative results for the three methods demonstrated a high degree of correlation. For a low Sn addition (X = 5 wt.%), solidification path starts with α-Al dendrite formation, followed by θ-Al2Cu precipitation, and ends with an eutectic reaction. The two alloys with higher Sn compositions (X = 10 wt.% and X = 20 wt.%) exhibit comparable dynamics at the outset of their solidification paths with low Sn composition alloy. However, the formation of the primary α-Al phase is followed by liquid phase separation (nucleation and growth of Sn droplets in the melt) and a monotectic reaction before the final eutectic reaction.

Keywords :Al-Cu-Sn alloys, Thermo-Calc, solidification microstructures, liquid phase separation, monotectic, DSC, in situ radiography.

Conference Name :International Conference on Advanced Materials Science and Nanotechnology - (ICAMSN-24)

Conference Place Rome, Italy

Conference Date 4th Nov 2024