Superplastic extrusion of microgear shaft of 10 μm in module

Abstract The goal of this study is to establish microforming technologies for MEMS parts such as microgears of 10 micrometers in module. For this purpose, it is important to develop new methods to fabricate microdies and to select suitable materials for microforming. Photochemically machinable glass has been used to fabricate microdies by photolithography and anisotropic etching techniques. Al-78Zn superplastic material has been employed in microextrusion. This material has the great advantage of deformation under very low stresses in comparison with conventional plastic deformation. Furthermore, the material exhibits good microformability. A new superplastic forward extrusion machine has been developed for this study. Specimens were placed in a container and extruded by a linear actuator in a vacuum or an argon gas atmosphere. Microextrusion has succeeded in forming microgear shafts. The gear of Al-78Zn superplastic alloy is 10 micrometers in module and the diameter of the pitch circle is 100 micrometers.