改进型蜡基粘结剂的喂料流变性能

Rheological properties of metal injection molding feedstock using the improved wax-based binder

研究了改进型蜡基粘结剂体系和Fe 2Ni粉混合制备的喂料的流变性能 .结果表明 ,喂料是一种假塑性流体 ,其非牛顿指数n较大 ,15 0℃时n为 0 .5 2 ,恒剪切速率粘流活化能ΔEη=5 3.8kJ·mol-1·K-1,相对较低 ,由此说明该喂料具有良好的注射填充性 .粘结剂体系中加入油和改性剂能明显改变喂料的流变性能 .油使喂料粘度下降 ,假塑性行为变弱 ,粘度对温度的敏感性降低 ;改性剂使喂料粘度增加 ,粘流活化能略有下降 .

Metal injection molding (MIM) feedstock is a fully filled multiphase flow system, which exhibits complicated flow behaviour, and its rheological properties have significant influence on the MIM process. The rheological properties of MIM feedstock using the improved wax-based binder were studied in this paper. The results show that the feedstock exhibits good rhelogical properties. The feedstock possesses pseudo plasticity, the power law exponent and the activating energy for viscous flow were suitable for MIM. The content of oil and modifer in the binder had obvious influence on the rheological properties of feedstock. After adding oil, the viscosity, the pseudo plasticity, and the flow activation energy viscosity of feedstock decrease. Modifer increases the viscosity of feedstock and decreases the sensitivity of viscosity to temperature change.