电磁搅拌制备的Al-5Ti-1B对6061铝合金显微组织和力学性能的影响

Effect of electromagnetic-stirred Al-5Ti-1B on microstructure and mechanical properties of 6061 aluminum alloy

采用电磁搅拌连续铸挤工艺制备Al-5Ti-1B晶粒细化剂,研究了Al-5Ti-1B添加量对6061铝合金显微组织与力学性能的影响。结果表明:添加质量分数为0.1%的Al-5Ti-1B,6061铝合金的显微组织从171μm的粗大枝晶细化成平均直径为70μm的等轴晶,合金的抗拉强度提高了26.47%,伸长率提高了50.91%。随着Al-5Ti-1B的质量分数从0.1%逐渐增加到0.5%,6061铝合金的晶粒进一步细化,抗拉强度和伸长率进一步提高,但晶粒细化效应逐渐减弱。当Al-5Ti-1B添加量为0.5%时,6061铝合金被细化为平均直径为37μm的等轴晶,合金的抗拉强度和伸长率分别为243 N/mm2和10.5%。与未添加Al-5Ti-1B的6061铝合金相比,抗拉强度和伸长率分别提高了42.95%和90.91%。

The Al-5Ti-1B grain refiner was prepared by the continuous casting and extrusion process with electromagnetic stirring. The effect of the Al-5Ti-1B content on mierostructure and mechanical properties of 6061 aluminum alloy were studied. The results show that when the mass fraction of the Al-5Ti-1B addition is 0.1% ,the microstructure of 6061 aluminum alloy is refined from the coarse dendrite grain with the diameter of 171 μm into the equiaxed grain with an average grain diameter of 70 μm. The tensile strength is increased by 26.47% and the elongation is increased by 50.91% compared with that of 6061 aluminum alloy without A1-5Ti-1B addition. With the mass fraction of Al-5Ti-1B increasing from 0.1% to 0.5% ,grains of 6061 aluminum alloy are further refined,the tensile strength and elongation are improved further, but the grain refinement effect is weakened gradually. When the Al-5Ti-1B addition is 0.5% ,the average grain diameter of 6061 aluminum alloy is 37 μm,the tensile strength is 243 N/mm^2 and the elongation is 10.5%. The tensile strength is improved by 42.95% and elongation is improved by 90.91% compared with that of 6061 aluminum al- loy without A1-5Ti-IB grain refiner.