Effect of La on Structure and Properties of ZL101A Alloy
The micro/macro-structure and properties of the ZL101A alloy added different La amount after heat treatment were studied.The results show that a significant modifying effect on ZL101Acan be achieved in metal mould casting by adding 0.6% La the eutectic Si in the modified alloy becomes finer spot-shaped morphology.The grain is refined remarkably after adding La and the average grain size is decreased from 3 mm to 1 mm.The modification of eutectic silicon and the refinement of grain are mainly attribute to the enrichment of La at the front edge of eutectic,which counteracts the eutectic Si growing up.With the increase of La amount,the tensile strength and elongation increase markedly.But excessive La has bad effect on tensile strength and elongation.