Fabrication of micro gear by micro powder injection molding

Abstract

Micro components made from polymers can be easily processed but they may not be suitable for all applications. One example is where good mechanical properties are required. Thus, the fabrication of micro components from non-polymeric materials such as metals and ceramics is essential. In this paper, the fabrication of 316L stainless steel micro gear by micro powder injection molding is reported. The specifications of the green micro gear were: 10 teeth, module of 0.08, outer diameter of 1 mm and a length of 1 mm. Injection molding was conducted on a conventional injection molding machine with a small screw diameter of 14 mm. The green micro gear was well replicated. The debound micro gear retained its shape and the teeth were well defined. After sintering, the shape was also retained but with some surface irregularities. The process differences between lPIM and PIM, such as the use of smaller particle size and higher mold temperature are also highlighted.

Micro injection molding of micro gear using nano-sized zirconia powder

“…Adhesive force between the feedstock and micro-cavities can exceed the material strength resulting in incomplete demolding. The use of the variotherm mold is recommended to ensure complete filling of the micro features and high green strength for demolding (Loh et al 2008). Fleischer et al (2006) on the other hand suggested the development of a special ejection system with ejector pins of inner diameter 525 lm, surrounding the inner core of feature to ensure shape retention during demolding.…”

Factors affecting the replication quality of micro metal gears produced by μ-PIM

“…Researchers in Singapore started to investigate replication of simple micro structures with 316L stainless steel by l-PIM cooperating with Japanese scientists. Micro rod arrays with diameters of 80 and 100 lm, micro square arrays with dimensions of 100 lm, and recently micro gear with diameter of 1 and 1 mm in height have been obtained by l-PIM (Liu et al 2001a, b;Tay et al 2006;Loh et al 2007).…”

Comparative study of conventional and micro WEDM based on machining of meso/micro Sized Spur Gear

“…It can be fabricated directly or by replication using polymer, metals, ceramics, etc.. 16 Robotics, optical adjustment, drug delivery, surgical instrument, control of micro fludic nozzles, etc. are the few of many applications of micro gear systems.…”