Al-4.5Ti-B细化剂和Na盐变质剂对A357合金组织和性能的影响

Effects of Al-4.5Ti-B Refiner and Na Modifier on Microstructures and Mechanical Properties of A357 Alloy

研究了Al-4.5Ti-B细化剂和Na盐变质剂对A357合金金属型铸造时微观组织和力学性能的影响及Na盐变质砂型铸件的壁厚效应。实验结果表明,单独Ti细化和Na盐变质的最佳加入量分别为0.15%、1.5%。在两者共同作用时,合金的力学性能比Ti细化低,比Na盐变质高。随砂型铸件壁厚的增加,A357合金的组织变得粗大,硬度变小,并且固溶处理和时效处理所需的时间也更长。

Effects of Al-4. 5Ti-B refiner and Na modifier on the microstructures and mechanical properties of A357 alloy during permanent mould casting are experimentally studied, and the sensitivity to thickness effect during sand-casting is studied as well. The results show that the optimal addition of AI-4.5Ti-B refiner and Na modifier are 0.15wt% and 1.5tw% respectively. The effect of combined addition on the mechanical properties are higher than Na modifier alone, however, lower than A1-4.5Ti-B refiner alone. The eutectic silicon phases of A357 alloy become coarser, and hardness becomes lower with increase of thickness of sand casting. The time for solution treatment and aging treatment get longer.