Effects of AlTi5B1 on Structure and Properties of Hypoeutectic Al-Si Alloy

The influence of AlTi5B1 content on microstructure and mechanical properties of hypoeutectic Al-Si alloy was studied.The results show that the AlTi5B1 content exerts a greater influence on the tensile strength of alloy and when Ti reaches 0.06wt.%,the tensile strength reaches its maximum.The influence of AlTi5B1 content on elongation is similar to tensile strength.AlTi5B1 content has a smaller effect on the hardness of alloy.After inoculation with AlTi5B1,the quantity of TiB2 and Ti(A11-x,Six)3 as effective nucleation cores increases,which play a major role in the refinement.The morphologies and distributions of second-phase(Fe phase,AlCu phase)change,which intensifies grain boundary and weakens Fe phase's negative action.