稀土磁性塑料充模流动过程模拟

介绍了用高压毛细管流变仪,测试研究钕铁硼磁性塑料的流变特性,并利用非线性回归分析技术得到的流变参数,建立流动本构方程和钕铁硼流变体在注射模浇注系统内的流动模型,运用该模型对磁性材料注射模流道和浇口设计、流道料的冷却凝固时间等进行优化。实验及其分析表明,钕铁硼熔料体系符合假塑性连续流体的流动特性,遵从幂律流体的流动模型,具有超高的熔体粘度,在流道内流动压降远远高于普通塑料流动压降,有其特殊的成型加工规律。

Mould-Filling Flow Process Simulation of Rare-earth Magnetic Plastics

The theological behavior of NdFeB magnetic plastic was tested and investigated by means of high pressure capillary rheometer. The heological parameter, attained by nonlinear regression analysis technology, was applied to establish the flow constitutive equation and the flow model of NdFeB rheid in the feeding system of injection mould. This model was used to optimize the injec- tion mould design, including the spree runner, the gate and the cooling and solidification time of plastics in running channel, etc. The experiment and analysis shows that NdFeB melting stock conforms to the flow characteristic of pseudo plasticity continuous fluid and follows the flow model of power law fluid. It has ultrahigh viscosity and its flowage pressure drop in spree runner compares far too higher to that of ordinary plastics, As a result NdFeB magnetic plastic has its special forming method.