Refining performance of Al–3Ti–0.2C–5Sr on A356 alloy and electron microanalysis of ternary Al–Ti–Sr phases

The effect of Al-3Ti-0.2C-5Sr（wt%） grain refiner on the refining performance and modification of A356 alloy was investigated using optical microscope（OM）.The morphology and crystal structure of ternary Al-Ti-Sr phases in Al-3Ti-0.2C-5Sr refiner were analyzed by scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.The results show that the ternary Al-TiSr phases in Al-3Ti-0.2C-5Sr refiner can promote the grain refining efficiency of A356 alloy.The ternary Al-Ti-Sr phases co-exist in two morphologies,i.e.,blocky-like phase and surround-like phase,besides,which both have the same chemical composition of Al34Ti3Sr.The crystal structure of Al34Ti3Sr is face-centered cubic,and the lattice parameter is determined to be about 1.52 nm.