退火温度对8079铝合金微观结构和力学性能影响的研究

Effect of Annealing Temperature on Microstructure and Mechanical Properties of 8079 Aluminum Alloy

8079铝合金作为一种新型的Al-Fe合金,具有很多优异的性能。而未经热处理的8079铝合金含有粗大晶粒及针状的铝铁脆相,这些缺陷会降低合金的性能。退火可以使合金均匀化、减少位错等缺陷,进而提高性能。本论文对8079铝合金进行不同温度退火处理,采用X-射线衍射仪、金相显微镜、扫描电子显微镜观察合金微观结构,采用拉伸实验和硬度测试总结合金力学性能的变化。研究表明:随着退火温度的升高,8079铝合金抗拉强度降低,硬度下降,韧性提高。当退火温度在500℃时,晶粒大小均匀;退火温度继续提高时,晶粒急剧长大,降低合金的性能。

As a new Al-Fe alloy,8079 aluminum alloy has many excellent properties.However,the 8079 aluminum alloy without heat treatment contains coarse grain and needle-like Al-Fe brittle phase,which will reduce the performance of the alloy.Annealing can homogenize the alloy,reduce the dislocations and improve the properties.In this paper,8079 aluminum alloy was annealed at different temperatures,and the microstructure of the alloy was observed by X-ray diffraction,metallographic microscope and scanning electron microscope.The results show that the tensile strength and hardness of 8079 aluminum alloy decrease with the increase of annealing temperature,and the toughness was increased.When the annealing temperature is 500℃,the grain size was uniform.When the annealing temperature continues to increase,the grain size increases sharply and the properties of the alloy decrease.