Al-5Ti-1B对Al-Zn-Mg-Cu合金铸态组织与力学性能的影响

Effect of Al-5Ti-1B on microstructure and mechanical properties of as-cast Al-Zn-Mg-Cu alloy

研究了电磁搅拌连续铸挤Al-5Ti-1B晶粒细化剂对Al-Zn-Mg-Cu合金铸态组织与力学性能的影响。结果表明:Al-5Ti-1B是Al-Zn-Mg-Cu合金的有效晶粒细化剂,添加质量分数为0.1%的Al-5Ti-1B,可使Al-Zn-Mg-Cu合金铸态组织从粗大的枝晶细化为平均直径为54μm的等轴晶,抗拉强度和伸长率提高5.5%和35.6%;随着Al-5Ti-1B的质量分数从0.1%增加至0.5%,Al-Zn-Mg-Cu合金的晶粒进一步细化,抗拉强度和伸长率继续提高;当Al-5Ti-1B的质量分数为0.5%时,Al-Zn-Mg-Cu合金被细化为平均直径为38μm的等轴晶,合金的抗拉强度和伸长率提高到313 MPa和4.2%,与未添加Al-5Ti-1B相比,分别提高了13.8%和48.2%。

The effects of Al-5Ti-1B grain refiner on microstructure and mechanical properties of as-cast Al-Zn-Mg-Cu alloy were studied. Results show that the Al-5Ti-1B is an efficient grain refiner of Al-Zn-Mg-Cu alloy. When the additive amount of Al-5Ti-1B grain refiner is 0.1%, the microstructure of Al-Zn-Mg-Cu alloy can be refined from coarse dendrite to equiaxed grains with average diameter 54 p.m and the tensile strength and elongation are increased by 5.5% and 35.6%, respectively. With the increase of additive amount of Al-5Ti-1B grain refiner from 0.1% to 0.5%, the grains of Al-Zn-Mg-Cu alloy are further refined and the tensile strength and elongation are further improved. When the additive amount of Al-5Ti-1B grain refiner is increased to 0.5%, the grains of Al-Zn-Mg-Cu alloy are refined to equiaxed grains with average diameter 38 μm and the tensile strength and elongation are improved to 313 MPa and 4.2%, respectively, which are increased by 13.8% and 48.2% compared with that of Al- Zn-Mg-Cu alloy without adding Al-5Ti-1B grain refiner.