Effect of Particle Size in Feedstock Properties in Micro Powder Injection Molding

Abstract

Micro powder metal injection molding has received attention as a manufacturing technology for microparts. Small powder size is very useful in achieving detailed structures. STS nanopowders with an average diameter of 100 nm and STS micropowders with an average diameter of 5 micron were utilized to produce feedstock. The mixing behavior of the feedstock was indicated that the nanoparticle feedstock produce highest mixing torque at various powder_loading than the micropowder feedstock. Ares rheometer was utilized to examine visco-elatic flow behavior. The nanoparticles feedstocks showed that elastic properties are dominant in flow behavior and high viscosity. Whereas the micropowders feedstocks, viscous properties are dominant in flow behavior and less viscosity.

Micro metal injection molding (MicroMIM)

“…13.5). Similar goals are pursued by other study groups in Japan (Yasui et al, 2006) and Korea (Baek et al, 2006), among others.…”

“…Besides requiring low feedstock viscosities and high strengths of the green parts, MicroPIM, in the same way as classical PIM technology, depends on factors such as feedstock homogeneity, shelf life and recyclability, easy and environmentally friendly debindering, and controllable shrinkage behavior (Kipphut and German, 1991;Baek et al, 2006). The most popular binder systems for commercial and scientific uses are categorized as follows:…”

A review of micro-powder injection moulding as a microfabrication technique

“…Due to the significant effect of powder size on part quality, current research focuses on developing powders with relatively small particle size and narrow distribution using techniques such as gas atomisation [1,7,13]. Nanopowder is a current area of investigation for µPIM [3,40,62], where…”

“…Nevertheless, some nanopowders have already been developed and tested successfully on a lab scale. Spherical particles of nanopowder of 316L with average diameter of 100 nm are used in µPIM to produce micro-components [62,63]. Ceramic powders of 600 nm and smaller are used for µPIM [7,46,60].…”

Effect of carnauba wax as a part of feedstock on the mechanical behavior of a part made of 4605 low alloy steel powder using metal injection molding

“…For application of carnauba wax in stainless steel metal injection molding binder systems, one can refer to the Studies done in this field, where 15 vol.% of carnauba wax in binder system of 316 L-TiC was used and studied the rheological behavior [10]. In another study 20 wt.% carnauba wax for injection molding of 316 L stainless steel powder was utilized [11]. Also, injection stainless steel powder using binder system consisting of paraffin wax, polypropylene (PP), carnauba wax, and stearic acid in order to produce micro-porous austenitic stainless steel was conducted [12].…”