Abstract:Pore opening and binder flow during the initial stage of thermal debinding in metal injection molded parts was investigated. Scaning electron microscopy(SEM) pictures of 316L stainless steel parts using wax-based binder show that small particles will move to the surface with the process of debinding. SEM pictures of different mass loss rate specimens indicate that initial pores will emerge when as little as 4% binder removes. During the initial stage of thermal debinding, vapor tension varies in different place due to the difference of curvature. Thus more binders will be removed in places with smaller cavity between metal powders, and in these places small openings emerge.

Key words: metal injection molding; thermal debinding; pore opening; binder flow