Outcome of mix Ce and Er addition on solidification microstructure of the LM25 ( Al-7Si-alloy)

Abstract

This paper highlights the effects of the additions of two rare earth elements (Ce and Er) on microstructure and to investigate the characteristic temperatures during solidification to five modified alloy. Al-7Si alloys with xEr + xCe additions (x = 0.15, 0.25, 0.4, 0.5 and 0.75) were produced by casting technique via the solidification parameters examined using computer-aided cooling curve thermal analysis (CACCTA). The thermal analysis tests were carried out for each one by using a thermal analysis system that includes (K-type Thermocouple, EPAD2-TH8-K, EPAD-Baes and Laptop with Dewesoft-7.5-Lt). To estimate the change in microstructure and solidification as a result of adding (Ce + Er) additions the obtained result showed that the growth TGAl-Phase and nucleation TNAl-Phase temperatures decreased to lower temperatures 614.7 °C and 615.5 °C respectively as the amount Ce, Er increased. A high amount of Ce, Er (1.5%) addition reduces the size of the platelet Si-intermetallic to very fine form.