Study on the Morphological Feature and Formative Mechanism of Al-35La Alloy

摘要

we found that the microstructure of Al-35% La alloy is different from the common microstructure ofrnhypereutectic alloys during the conventional casting process, the first crystalline phase is Al_(11) La_3, which composition isrndiscontinuous along the growth direction, the main dendrite is composed of α-Al alternating with Al_(11) La_3, the results of SEMrnand XRD show that the chemical composition along the main dendrite exhibits periodic behavior, the organizationalrnmorphology is also discontinuous along the growth direction in the microstructure of Al-35% La alloy during the directionalrnsolidification process, therefore, this microstructure is named as periodic two-phase dendrite structure. Finally, werndiscussed the formative mechanism of this microstructure based on the above experiments.