N掺杂型Al-4Ti-1C对A356合金细化及力学性能的影响

Refining and Strengthening Performance of N-doped Al-4Ti-1C Refiner on A356 Alloy

目的提高A356合金的断裂伸长率。方法采用铸造法制备了一种N掺杂型Al-4Ti-1C细化剂(简称Al-4Ti-1C),研究了其对A356合金的晶粒细化行为及对力学性能的影响。结果与传统的Al-5Ti-1B细化剂相比,Al-4Ti-1C不仅能有效细化A356的α-Al晶粒,而且能够明显细化其枝晶臂间距,细化后α-Al的平均晶粒尺寸为231μm,枝晶臂间距为28μm;而Al-5Ti-1B细化后分别为253μm和50μm。该细化剂对A356合金力学性能的提升也优于Al-5Ti-1B,细化后A356的拉伸强度和伸长率为298 MPa,4.0%,与Al-5Ti-1B的细化结果(292 MPa,3.0%)相比,伸长率提高幅度达33%。结论 Al-4Ti-1C是一种有效的A356晶粒细化剂。

This work aims to improve the elongation at break of A356 alloy. A type of N-doped Al-4Ti-1C（named Al-4Ti-1C） refiner was prepared via casting method, and the refining and strengthening performances of the refiner on A356 alloy were investigated. Compared with the conventional Al-5Ti-1B refiner, Al-4Ti-1C performed well on refining α-Al grains and their dendritic arm spacing, with an average size of 231 μm and 28 μm respectively, while they were just 253 μm and 50 μm when refined by Al-5Ti-1B. The refiner＇s improvement on mechanical properties of A356 alloy was also superior to Al-5Ti-1B. When changing refiners from Al-5Ti-1B to Al-4Ti-1C, the ultimate tensile strength（UTS） of A356 increased from 292 MPa to 298 MPa and the elongation increased from 3.0% to 4.0%, with a percentage increase of 33%. Al-4Ti-1C presents to be an effective refiner for A356 alloy.