Fabrication of 316-L stainless steel micro parts by softlithography and powder metallurgy

This paper presents an approach to fabricate 316-L stainless steel micro parts with complex shapes using soft lithographical and powder metallurgical techniques. The process includes production of high quality deep micro SU-8 master moulds and their negative replicas in polydimethylsiloxane (PDMS). Then the PDMS soft moulds are filled with slurry containing superfine (< 4 um) stainless steel particles and binder. When the slurry is dry, green patterns are removed from the PDMS moulds before the patterns are de-bound and sintered in the tube furnace at 1200 in forming gas atmosphere. The resultant micro parts show high shape retention. The linear shrinkage of the sintered part is measured and found to be 17%.