以自蔓延法合成的AlN粉末为原料,加入5% Y2O3(质量分数,下同)为烧结助剂,选用石蜡(PW)、聚丙烯(PP)和硬脂酸(SA)粘结剂体系制成注射成形喂料,使用毛细管流变仪测定喂料的流变参数,通过线性回归分析,计算出非牛顿指数和粘流活化能.结果表明:喂料的粘度随着温度的升高以及剪切速率的增大而减小,具有较好的充模性,呈假塑性流体.在三种组分的喂料中,聚丙烯(35%)、石蜡(60%)和硬脂酸(5%)粘结剂体系与AlN粉末形成的喂料的综合流变性能最好,在160℃和526.02s^-1剪切速率条件下,其粘度η,非牛顿指数n和粘流活化能E分别为277.93 Pa·s,0.5074和24.94kJ·mol^-1.
The rheological characteristics of feedstock for AlN powder injection molding were investigated. The AlN powder as a raw material was synthesized by self-propagating high-temperature synthesis (SHS) and the polymer-wax binder consist of paraffin wax (PW), polypropylene (PP) and stearic acid (SA). By using capillary rheometer, rheological parameters of the feedstock were determined. The non-newton index and viscous flow activation energy were calculated by means of regression analysis on the computer. The results showed that all feedstock was pseudoplastic fluid for their viscosity decreased with increased temperature and shear speed. Of all feedstock, the comprehensive rheological characteristic of feedstock with PP (35%, mass fraction), PW (60% ,mass fraction) and SA (5% ,mass fraction) was best. Its viscosity, non-newton index and viscous flow activation energy were 277.93Pa·s, 0. 5074 and 24. 94kJ·mol^-1 under the condition of temperature 160℃ and shear speed 526.02s^-1.