Rheological Behavior of 316L Stainless Steel Powder Plastisols

Abstract

The objective of this work is to elucidate the rheological behavior and then to optimize the properties of plastisols loaded with 316L water- and gas-atomized powders, as feedstock of Metal Injection Molding (MIM) process.
The results obtained were summarized as follows:
(1) Judging from powder/binder mixing torque, mixture viscosity is greatly influenced by powder characteristics (shape, size) and generally, related to its tap density.
(2) Practically, water-atomized powder (irregular) needs thermoplastic binder approximately 2.5wt% more than gas-atomized one (spherical) to prepare the optimal feedstock.
(3) Powder plastisols show Bingham-type flow behavior and consequently, give almost the same viscosity-shear rate relationship all over the powders for the optimal solids loading (Φ_o).