Fabrication of Micro Porous Metal Components by Metal Injection Molding Based Powder Space Holder Method

Abstract

A novel production method for the metal components with micro-sized porous structures has been developed by applying the powder space holder (PSH) method to the metal powder injection molding (MIM) process. This production method is compatible with widespread applications with high functionality such as heat sinks, electrodes and medical implants and so on. These applications can benefit from the advantages provided by micro-porous metal components with complicated shapes using most kinds of metal powder. The aim of this study is to clarify the effects of material combinations and production conditiorfs on the pore formation and some physical properties of sintered porous metals. The green compacts were molded via uniaxial hot pressing for an experiment using various porous compounds which were prepared by changing the combinations in size of stainless steel 316L powder and polymethylmethacrylate (PMMA) space holding particle. Afterwards they were sintered at various temperatures after thermal debinding. It was confirmed that the size of metal powder and space holding particle together with the sintering temperature were main 'Correspondence to Prof. K. Nishiyabu factors affecting the pore size, porosity, surface area and shrinkage of sintered porous metals. It was concluded that the PSH-MIM method proposed was useful for producing metal components with micro-sized and high functionally porous structures.

Increased Shape Stability and Porosity of Highly Porous Injection‐Molded Titanium Parts

“…However, PMMA, NaCl, and KCl are stable at MIM temperatures. These materials in powder form are usually used as space holders for the manufacturing of porous titanium by MIM . If the salts are applied as a space holder, pores are usually created by dissolution of NaCl or KCl particles in warm water (Figure , route A).…”

“…Nishiyabu et al first demonstrated the potential of MIM for manufacturing net‐shaped parts with functional macropores using a fine‐grained 316L powder and PMMA space holder . Porosity up to 80% was achieved by using a special combination of metal and space holder particles sizes.…”

Processing of polymer-derived porous SiC body using allylhydridopolycarbosilane (AHPCS) and PMMA microbeads

“…The incorporating conditions of the microbeads for successful bulk formation and the formation process of porous microstructure were examined. This sacrificial filler template approach has been called "powder space holding (PSH) method", 33)35) a preexisting powder metallurgical technique's name, by the authors.…”

Corrosion Protection of Injection Molded Porous 440C Stainless Steel by Electroplated Zinc Coating

“…MIM has gained a solid commercial position as a manufacturing technique for stainless steel parts [24]. The fabrication of porous 316L stainless steel by combining the MIM and PSH methods has been demonstrated by using poly(methyl methacrylate) (PMMA) as a space holder [25][26][27].…”