锻造工艺对7A09铝合金锻件晶粒组织的影响

采用7A09铝合金过热处理工艺实验,研究其过热显微组织形态;采用4种锻造温度(440、460、480、500℃)对应3种变形程度ε(45%、68.3%、76.7%)进行了锻造实验,分析了锻造温度和变形程度对锻后晶粒组织的影响。过热处理工艺实验研究表明,随着加热温度的升高、保温时间的延长,晶粒变大;在加热温度440℃保温时间6 h后锻件的显微组织图上出现了织构组织,在加热温度500℃保温时间10 h后过烧现象明显;锻造工艺实验研究表明,获得锻后晶粒细小组织的最佳锻造工艺参数是锻造温度440℃和变形程度76.7%。

Effect of Forging Process on Microstructure of 7A09 Aluminum Alloy

The microstructure of 7A09 aluminum alloy during overheat experiments was studied. The experiments were carded out by forging at the four kinds of deformation temperature （440,460,480,500℃） for the three kinds of deformation degree （ε = 45% ,68.3% ,76.7% ） respectively to analyze the effect of forging temperature and deformation degree on the mierostructure. The result of overheat experiments shows that the grain size increases continuously with the increase of heating temperature and holding time. After 7A09 aluminum alloy was annealed at 440℃ for 6 h, recrystallization texture appeared; after annealed at 500 ℃ for 10 h, burning structure appeared. The deformation degree of 76.7% at 440 ℃ is the best processing parameter for gain refinement during forging.