FABRICATION OF MICRO GEARS BY MICRO-POWDER INJECTION–COMPRESSION MOLDING

Micro-spur gears were fabricated by powder injection–compression molding and micro-two-step gears were produced through stacking and sintering of the green parts. Shrinkage of micro-gears by sintering was larger in teeth and with increase of compression pressure, shrinkage was decreased due to increase of density in green parts. Surface roughness of sintered body was reduced to a few hundreds of nanometers by ultrasonic micro-polishing. The joining of green bodies by stacking and sintering was achieved using the pressurized sintering and insert of feedstock powders between both green bodies.