Cold-isopress-based process for fabrication of stainless steel micromachine components

This letter presents in detail a new process for the fabrication of 3D stainless steel microcomponents using cold-isopressing techniques. The process starts by producing deep SU-8 master moulds and their negative soft micromoulds in polydimethylsiloxane (PDMS), preparing stainless steel semi-solid paste with high solid loading, filling the soft micromoulds, covering the filled moulds and putting them under hydrostatic pressure. After the pressure is released the green microparts are obtained, de-bound and sintered in vacuum at 1350degC. The resultant microparts show the same quality as the SU-8 master moulds without deformation. The effect of applied hydrostatic pressure on the density of the green and sintered parts as well as the linear shrinkage is discussed in detail. The maximum density of the sintered parts and its corresponding linear shrinkage are found to be 98.6 and 13deg, respectively.