粉末微注射成形Catamold~ 316L喂料流变性能研究

采用Rosand RH7双柱塞高压毛细管流变仪对BASF Catamold316L奥氏体不锈钢喂料进行流变性能研究.讨论了在口模直径为1mm,长径比为16,Bagley校正条件下不同剪切速率、温度对喂料粘度、非牛顿指数、粘流活化能的影响,同时从理论上分析了粉末装载量及粘结剂选取对喂料流变性能的影响,并且对喂料的流变性能进行综合评价.实验结果表明,Catamold316L喂料呈现假塑性流体特征,200℃时非牛顿指数和粘流活化能最小,可塑性指数最大,更加适合注射成形;随着温度的升高、剪切速率的增大,粘度均逐渐降低,粘度对剪切速率具有很高的敏感性;在相同的剪切速率下,随着温度的升高,喂料综合评价指标呈现先增大后减小的趋势.

Rheological Properties of Catamold 316L Feedstock of Micro Powder Injection Molding

The high-pressure Dual-plunger capillary rheometer Rosand RH7 was adopted to research the rheolog- ical properties of BASF Catamold ？ 316L austenitic stainless steel feedstock. We investigated the effects of different shear rates and temperatures on the viscosity of feedstock,non-Newtonian index and viscous flow activation energy when the die diameter of the capillary was 1 mm,the length-to-diameter ratio was 16,and the Bagley was used for correction,theoretically analyzed the influence of powder loading capacity and binder selection on the rheological properties,and comprehensively evaluated the rheologicaI properties of feedstock. The results showed that the Cata- mold？ 316L feedstock was characteristic of pseudoplastic fluid and powder injection molding was more suitable when at 200℃ the non-Newtonian index and viscous flow activation energy were minimum and the highest mold- ability index was maximum, and that the feedstock viscosity decreased and viscosity was highly sensitive to the shear rate with the increase of the temperature and shear rate, and with the increase of temperature, the comprehen- sive evaluation index of feedstock first increased and then decreased at the same shear rate.