Effect of Ce addition on hot tearing behavior of AZ91 alloy

Publication date: Available online 1 October 2019Source: Progress in Natural Science: Materials InternationalAuthor(s): Wenjun Liu, Bin Jiang, QingshanYang, JianquanTao, Bo Liu, Fusheng PanAbstractA small amount of cerium (below 1.0 wt%) addition to AZ91 alloy have been investigated on the hot tearing susceptibility (HTS) at a cooling rate of 1.5Ks−1. The HTS increased to a maximum value with a cerium addition of 0.6 wt% and then decreased to a stable status as cerium was gradually added. Due to high chemical activity, cerium into the melts can react with aluminum to form an Al11Ce3 intermetallic compound. X–ray diffraction results also confirmed the existence of Al11Ce3. The Al11Ce3 increased with the presence of the needle-like and block morphology. As cerium levels increased, the amount of Mg17Al12 decreased. The variations between Mg17Al12 and Al11Ce3 resulted in a similar normal distribution of the HTS in AZ91 alloy. The findings were further verified through the microstructure evolution and the surface morphology of fracture.Graphical abstract
Source: Progress in Natural Science: Materials International - Category: Materials Science Source Type: research