Tailoring the Porous Microstructure of MIM Flow Restrictors

摘要

Despite being known by its ability in the production of nearly full dense sintered parts, Metal Injection Molding (MIM) allows also tailoring porous microstructures for special applications such as small-size flow restrictors. In other words, through simple modifications in the sintering parameters, an interconnected porous microstructure with the capability of control the gas flow rate from a high to low pressure region can be obtained. In this work, the effect of sintering temperature and time is addressed over two parameters: i- the microstructure evolution of the stainless steel parts and ii- the gas flow behavior in each component under different upstream pressures. Therefore, the parts were characterized in terms of porosity and shape factor by image analysis while a nitrogen flow test apparatus was used to elucidate the gas flow conditions. The results show that production of tailor-made flow restrictors is feasible by MIM.