7050铝合金铸锭中Al3Zr的析出情况对锻板性能的影响

Effects of Al 3Zr Dispersoids on Mechanical Properties of 7050 Forging Plates

本工作采用不同均匀化工艺和控制Zr的添加量等手段获得了不同Al 3Zr析出情况的7050铝合金铸锭,系统研究了Al 3Zr的分布情况对相同厚度的7050-T74锻板的拉伸性能以及断裂韧性的影响规律。结果表明,Al 3Zr弥散相分布越均匀、数量密度越高,对抑制合金再结晶的作用越强,获得的亚晶晶粒越细小均匀。同时Al 3Zr相的分布会影响锻件的时效效果,当Al 3Zr相越细小、分布越密集,材料中MgZn 2过渡相对应的峰时效时间会提前,采用相同的T74时效制度,相应锻板的过时效时间延长,导致其力学强度降低较多。

In this paper,7050 aluminum alloy ingots with different Al 3Zr precipitation conditions were obtained by using different homogenization processes and controlling the addition of Zr elements.The tensile properties and fracture toughness of 7050-T74 forged plates affected by Al 3Zr dispersoids were systematically studied.It is shown that the more uniform distribution and higher numberr density of the Al 3Zr dispersoids,the stronger the recrystallization inhibition effect,and the finer and more uniform subgrains could be obtained.At the same time,the distribution of Al 3Zr dispersoids could affect material’s precipitation formation during the aging process.When Al 3Zr dispersoid size is finer and number density is higher,the peak aging time of theη′phase in 7050 alloy material will be advanced,using the same T74 aging procedure,7050 forging plate’s strength would be decreased significantly.