控制参数对Al—Al3Ni共晶合金间距的影响

在不同温度梯度及生长速度下测量了Ａｌ－Ａｌ３Ｎｉ共晶合金间距选择范围。实验结果表明，在一定生长速度下，共晶间距存在一容许范围。其宽度随生长速度的增加减小，在某一温梯度下，共晶间距与生长速度的关系满足λ＾ｎｕ＝常数ｎ＝１．７－２．０）的关系，温度梯度增加，其最大，最小及平均间距离略有减小。同时，Ａｌ－Ａｌ３Ｎｉ合金的间距选择范围与初始生长速度无关。

INFLUENCE OF CONTROLLING PARAMETERS ONAl-Al3Ni EUTECTIC SPACING SELECTION

In order to establish eutectic spacing selection criterion for directionally solidified eutecticalloys, Al-Al3Ni interrod spacings were studied at different thermal gradients and growth velocities. It is shown that a sharp distribution of spacing is observed for a given velocity. The width of the distributionis found to decrease as the velocity is increased. The relationship between the spacing and pulling velocityfor a given thermal gradient can be expressed as v = constant when n is from 1.7 to 2.0. The maximum,minimum and average spacings will be slightly decreased while thermal gradient increases. Meanwhile,a number of velocity change experiments was also carried out and it is shown that spacing selection inAl-Al3Ni alloy is independent of the initial growth velocity for a given final velocity.