Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 12 No. 1 February 2002|
（1.State Key Laboratory for Powder Metallurgy,
Central South University,Changsha 410083,China;
2.Hunan Yingjie Limited Corporation of High Technology,
Abstract:Viscosity of a polyethylene glycol-polymethyl methacrylate (PEG-PMMA) binder and PEG-PMMA/Fe-2Ni feedstock in powder injection molding was measured and calculated.A logarithmic additivity between viscosity of the binder and that of its constituents was found.Other factors, such as temperature, powder loads,content and type of surface-active agents and those of polymers,in relation to rheological properties of feedstock were discussed as well.The results showed that with increasing viscosity of surface-active agent,polymer melt index or temperature,the feedstock viscosity decreased while higher polymer content and powder loading would lead to additional feedstock viscosity.The relationship mentioned above is expressed and effectively explained why the change rate of feedstock viscosity will slow down with the increase of shear rate.
Key words: powder injection molding;rheology;feedstock property