7075铝合金扁锭铸造缺陷研究

Study on Casting Defects of 7075 Aluminum Alloy Flat Ingot

用OLYMPUS金相显微镜、EDAX能谱分析仪等对不同铸造工艺条件下的7075铝合金扁铸锭进行显微组织和化学成分分析。结果表明,当7075铝合金扁锭铸造温度为735℃、铸造速度为43mm/min时,扁锭铸态组织晶粒细小,弥散相分布均匀,疏松和气孔等缺陷最少;通过对优化铸造工艺条件下的扁锭均匀化退火处理,当退火温度为465℃、退火时间为24h时,扁锭铸态组织偏析消除,晶粒分布更均匀,轧制后的铝板强度与未处理的相比更高。

In this paper, microstructure and chemical composition of flat ingot are analyzed by Olympus metallographic microscope and EDAX energy dispersive spectroscope under the different casting technique conditions. The results show that the as-cast structure has finer grain size,the dispersion phase distributed uniform,and the defects are least such as porosity,pore etc. when the casting temperature is 735℃,the casting speed is 43 mm/min. After homogenized annealing treatment,the segregation of as-cast structure can be eliminated,the crystal grains can be more uniformly and more higher strength of rolled aluminum plates when the annealing temperature is 465℃,the annealing time is 24 hours.