Fabrication of stainless steel micro components using softlithography

Mohamed Imbaby (a), Kyle Jiang (a), Isaac Chang (b)

(a) School of Mechanical engineering, University of Birmingham, Edgbaston, Birmingham, UK
(b) School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham, UK

Abstract

316-L stainless steel has good mechanical properties and has been widely employed for making different devices. This paper presents a study for making micro 316-L stainless steel components by soft lithography in combination with powder metallurgical processes. The process involves producing deep and solid micro moulds using SU-8 photo resist, making soft replica of the moulds using silicon rubber (PDMS), forming green patterns by filling stainless steel slurry into the PDMS moulds. The green parts are de-moulded, de-bound, and finally sintered in tube furnace including nitrogen atmosphere to obtain the final micro parts. The resultant micro components show good quality micro parts with complex geometry. The density of the sintered parts reaches 91.5% of the theoretical one and the linear shrinkage of the micro components after sintering is investigated and it is found to be dependent on the percentage of the solid loading in the green patterns. The fabrication process is described in detail and the results of characterization in shrinkage and density have been analysed.