成型模具对半固态铝合金组织的影响

Effect of Different Die Material on Microstructure of Semi-solid Aluminium Alloy

在半固态铝合金坯料制备试验中,选用导热系数不同的铜、钢、铁和粘土4种材料作成型模具。试验发现,在半固态制浆工艺参数相同的情况下,随成型模具材料的改变,半固态铝合金坯料的微观组织也不同。模具材料为铜时导热系数大,半固态坯料微观组织中的球晶组织圆整均匀细化,而模具材料为粘土时导热系数小,半固态坯料中微观组织粗大而且倾向于树枝晶。当模具厚度改变时也影响微观组织的形貌。

In the preparation of semi-solid aluminum alloy billet, the four different materials （copper, steel, iron and clay）with different thermal conductivity were used as die materials. The experimental results show that, under the same process parameters for semi-solid slurry preparation, the microstructure of semi-solid aluminum alloy is different with the change of die material; when the die material is copper with big thermal conductivity, the grain of semi-solid billet is spherical, uniform and small; when the die material is clay with small thermal conductivity,the grain of semi-solid billet is large and tends to dendrite; the changing of die thickness also affect the microstructure morphology of semi-solid billet.