The Effects of Al-5Ti-1B and Sr Interaction on Microstructure and Properties of ZL101

The effects of Al-5Ti-1B and Sr on the microstructure and properties of ZL101 alloy were studied, and the degree of eutectic Si modification was evaluated by solidification behavior. The results show that Al-5Ti-1B has a great effect on the refinement of primary α-Al dendrites, Sr has a great effect on the modification of eutectic Si, Al-5Ti-1B and Sr have a significant effect on the refinement of α-Al, and most of the eutectic Si is transformed from coarse lamellar to fine fibrous, but an incompletely modified region appears. Thermal analysis shows that the degree of undercooling in the primary α-Al and the nucleation rate is increased by the combined addition of Al-5Ti-1B and Sr, the effect of grain refinement is good, and the growth temperature of eutectic Si in the precipitation stage increases, and the metamorphic effect decreases slightly. More importantly, compared with the unmodified alloy, the alloy with Al-5Ti-1B and Sr addition combined increased the hardness by 9.8% and the electrical conductivity by 8.9%. The influence mechanism of the interaction between Al-5Ti-1B and Sr on the microstructure and properties of the alloy is discussed. Graphical Abstract