负压实型铸造金属基复合材料的成型理论研究

Theoretical Analysis on Forming FRM by V-EPC Process

负压实型铸造金属基复合材料的合金液前沿受到气化模气化产生的气体阻力 Pe、凝固阻力 Pf、毛细作用力 Pc、自身重力 G、纤维间的摩擦阻力 f以及充型时端部紊流引起的非线性力等 ,其中气体的阻力、凝固阻力、毛细作用力是主要的作用力。文中通过分析影响这些作用力的因素 ,提出了改善合金液充填的有效途径 :严格控制气化模中纤维的分布形态 ,使得合金液的充填速度均匀 ;控制浇注过程中的工艺参数 ;对纤维进行适当的表面处理 。

To analyze the process of forming FRM by V-EPC method, a mathematical model for liquid metal infiltration of a unidirectional continuous fiber array is established. The forces exerted on the flowing melt in vacuum-evaporative casting process include the pressure of the gasified EPS (P h), the internal viscous friction of the melt (P f), the capillary pressure (P c), the pressure difference (P z) between the flowing front and the runner, the gravity (G), etc. However, the former three of these forces are the key forces. The factors affecting these forces are analyzed. On the basis of the effective ways to improve infiltration process are also developed: to strictly control the fiber distribution in the EPS, to optimize casting parameters, to treat the surface of reinforcing fibers and ameliorate infiltrating properties. Steel fiber reinforced aluminum composite materials are successfully prepared by above control factors.