The photoacoustic technique and the thermal relaxation method were used to determine the thermal conductivity of some representative samples obtained from an aluminumsilicon casting alloy A319. This material was solidified with an imposed unidirectional thermal gradient to obtain samples with different microstructures characterized by the secondary dendrite arm spacing, which increases as the solidification rate decreases. It was found that the thermal conductivity of the alloy decreases with an increase in the secondary dendrite arm spacing and a decrease in the integral dendrite perimeter.
我们利用光声学技术和热弛豫方法测定了从
铝硅铸造合
金 A319 中获得的一些代表性样品的热导率。在施加单向热梯度的情况下对该材料进行凝固,以获得具有不同微观结构的样品,这些微观结构的特征是次生枝晶臂间距随着凝固速率的降低而增大。研究发现,随着二次枝晶臂间距的增大和整体枝晶周长的减小,合
金的热导率也随之减小。