离心加速场中液态浸渗纤维预制体动力学分析

INFILTRATION KINETICS OF METAL MELT INTO A FIBROUS PREFORM IN CENTRIFUGAL ACCELERATING FIELD

在将纤维预制体视为“毛细管束”基础上 ,采用达西定律建立了离心加速场中金属液浸渗纤维预制体的浸渗动力学模型。采用该模型分析了离心加速场中金属液浸渗纤维预制体的临界转速 ,考察了金属液浇注量、设备转速、铸件高度、金属液原始外半径以及纤维预制体孔隙率对离心加速场中金属液浸渗纤维预制体的影响。结果表明 ,金属液浸渗纤维预制体的临界转速只与临界压力、金属液的浇注量、铸件高度以及纤维预制体性质有关 ;增加金属液浇注量、设备转速及金属液原始外半径 ,降低铸件高度、预制体纤维体积分数 ,有利于金属液的浸渗。

The infiltration kinetics of the metal melt into a fibrous preform in centrifugal accelerating field is analyzed on the basis of Darcy's law and the assumption that the porous preform is treated as 'bundles of capillaries'.The critical rotate speed was analyzed with the established model.The influences of the metal melt weight,the rotate speed of the equipment,the casting highness,the originality outer radius of the metal melt and the fibrous volume fraction in fibrous preform on infiltration were studied.The results show that the critical rotate speed is dependent of the critical pressure,the casting highness,the metal melt weight and the character of fibrous preform.With the increases in the metal melt weight,the rotate speed of the equipment,the originality outer radius of the metal melt and the decrease of the casting highness,the fibrous volume fraction in fibrous preform,the infiltration of the metal melt for fibrous preform become more easiness.