机械振动对纯Al晶粒细化及凝固收缩的影响

研究了振动场对纯Al晶粒细化和凝固收缩的影响，并着重进行理论分析。实验结果表明：振动能明显细化晶粒，改善收缩。随着振动的加强，纯Al中心的等轴晶区逐渐增大，边缘部位的柱状晶区逐渐减小，当振击力达到81．87N时整个试样端面全部变为等轴晶。理论分析认为：振动引起的强烈冲击和搅拌作用使金属液产生晶粒游离、增殖、快速冷却是晶粒细化和收缩改善的根本原因。

Effect of Mechanical Vibration on Grain Refinement and Solidification Shrinkage of Aluminum

The effect of mechanical vibration on grain refinement and solidification shrinkage of aluminum was investigated in this paper.The results show that the grains of aluminum obviously are refined and the solidification shrinkage of aluminum is improved obviously under the different vibration strength.With vibration strengthening,the zone of equiaxed grain gradually increases and the zone of column grain gradually decreases.When the power of vibration reached 81.87N,the grains of aluminum became equiaxed grain in full section of casting.According to theoretical analysis,it was indicated that the basic reason for grain refinement and Solidification Shrinkage was sheared and multiplied grains in liquid and rapidly solidification caused by dramatic stirring of vibration on aluminum liquid.