用非晶合金細化變質處理A356鋁合金的顯微組織和力學性能

用非晶合金細化變質處理A356鋁合金的顯微組織和力學性能Microstructures and Mechanical Properties of A356 Aluminum Alloys after Modificated by Adding Amorphous Alloy

通過添加不同量的Zr56Co22Al16Ag6非晶合金條帶對用Al-5Ti-1B預細化的A356鋁合金進行細化變質處理，然后再進行固溶時效熱處理，研究了合金的顯微組織和力學性能，并探討了非晶合金的細化強化機制。結果表明：隨著非晶合金添加量的增加，鋁合金的晶粒尺寸和二次枝晶間距均逐漸減小，力學性能得到了提高；鋁合金的共晶組織中出現(xiàn)了彌散分布的顆粒狀Al3Zr相，該相作為非均質形核的核心，起到細化晶粒的作用；加入質量分數(shù)為0.4%的非晶合金，并設定孕育期為10 min，鋁合金可獲得最佳的細化效果，其經固溶時效處理后的抗拉強度和伸長率比未加入非晶合金的分別提高了7%和64.4%。

A356 aluminum alloy with Al-5Ti-1B pre-refine treatment was modified by adding various amounts of Zr56Co22Al16Ag6 amorphous alloy ribbons, and then solid solution and aging heat treatment was executed on the aluminum alloy. The microstructure and mechanical properties of the aluminum alloy were studied, and the amorphous ribbon's refine mechanism was also discussed. The results show that with the increase of amorphous alloy ribbon's adding amounts, grain size and the secondary dendrite spacing of the aluminum alloy all decrease, and the mechanical properties of the aluminum alloy are improved. Dispersed granular Al3Zr phase is found in eutectic structure, the phase increases the number of nucleus, hence refines the grains. Adding 0.4wt% Zr56Co22Al16Ag6amorphous alloy ribbons and setting incubation period of 10 min could make the aluminum alloy obtain the best refining effect, and after solid solution and aging treatment, tensile strength and elongation of the aluminum alloy owned the higher mechanical properties, compared with the aluminum alloy without adding amorphous ribbons, its tensile strength and elongation increased by 7%and 64.4%, respectively.