Effect of Ce on morphology of α(Al)-Al2Cu eutectic in Al-Si-Cu alloy
(1. Department for Materials and Metallurgy, Faculty of Natural Science and Engineering,
University of Ljubljana, A?ker?eva 12, SI-1000 Ljubljana, Slovenia;
2. University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, SI-2000 Maribor, Slovenia)
University of Ljubljana, A?ker?eva 12, SI-1000 Ljubljana, Slovenia;
2. University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, SI-2000 Maribor, Slovenia)
Abstract: The effect of Ce addition on the morphology of the α(Al)-Al2Cu eutectic in Al-Si-Cu alloy was investigated using thermal analysis, light microscopy, scanning electron microscopy, focused ion beam and energy dispersive analysis. The results show that the eutectic α(Al)-Al2Cu forms within small space between dendrites, silicon and AlSiFeMn plates. Eutectic Al2Cu is not lamellar but degenerated. However, Al2Cu in Ce-modified alloys is more compact. Ce partially dissolves in Al2Cu, which is a viable reason for the formation of coarser Al2Cu. The addition of Ce also increases the microhardness of the α(Al)-Al2Cu eutectic by almost 10% compared with the basic Al-Si-Cu alloy.
Key words: Al-Si-Cu alloy; cerium; eutectic; microstructure; focused ion beam