摘要
金属注射成形注射料在模腔中的流动是粉末与粘结剂的混合流动,其粘性行为与仅含粘结剂的单相流动有所不同。为研究注射料在微模腔中注射成形的粘性行为和微注射工艺的尺度适应性,在RH2000毛细管粘度仪依次安装直径0.3～2.0mm的7个毛细管,分别在160～220℃间的4个温度下对平均粒度为16μm的316L不锈钢注射料进行一系列粘度测试;测试显示注射料在同样的注射温度和切应变率下,应用不同管径的毛细管测试所得粘度存在差异的现象;解释壁面边界滑移速度是导致测试粘度差异的原因,分析影响粘度测试结果的因素;基于一系列的粘度测试结果,标定出壁面边界滑移速度的大小;提出注射料最小临界尺度的概念和标定方法,为微细金属注射成形工艺的尺度适应性研究提供有益的参考。
The mixture flow of feedstock in metal injection molding（MIM） includes flow of powder and binder,whose viscous behavior is different from the single-phase flow of polymer binder.The research on viscous behavior of MIM feedstock in the micro mold cavity and the minimum channel size proper for injection process are necessary.At four constant temperatures,the viscous behaviors of 16 μm 316L feedstock are tested by using seven capillary dies with diameter between 0.3 mm and 2.0 mm,which shows that the tested viscosities by different sizes of dies are not same even at the same temperature and the same shear rate;the difference of tested viscosity is explained and factors affecting the tested viscosity values are discussed;the boundary slip velocity on the capillary wall is calculated on the basis of a series of tested values;the concept of critical size is proposed and a method is suggested for the decision of minimum channel size injected by the 16 μm 316L feedstock.The method is also applicable for injection process with different size of feedstock.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2010年第12期43-47,共5页
Journal of Mechanical Engineering
基金
国家自然科学基金(10772154)
高等学校博士学科点专项科研基金新教师基金(20070613021)
中央高校基本科研业务费专项资金(SWJTU09CX067)资助项目
