Porous material produced by ceramic injection molding

Purpose: The aim of this research is presented the process of alumina injection molding with a multicomponent binder system based on polymer (polypropylene – PP/polyethylene- HDPE), paraffin wax (PW) and stearic acid (SA). Debinding and sintering process was also studied. Design/methodology/approach: The volume fractions of powder in the feedstocks were 50%vol and the volume of polypropylene and polyethylene were changed from 0-22%vol. The concentrations of SA were kept at 6%vol. The feedstock was heated to melt the binder and injected into a mold. Debinding process was carried out after injection step. The organic part was removed through combination of solvent and thermal debinding. Samples were sintered at 1200-1600°C in one cycle with debinding process. Findings: Thermogravimetric analysis (TGA) was performed to determine decomposition temperatures of polypropylene, polyethylene, paraffin wax and stearic acid. Morphology of alumina powder by scanning electron microscopy (SEM) was disclosed. The microstructure and properties was tested to see how the selected sintering parameter ,as a temperature, affects the structure. Originality/value: The paper presents ceramic injection molding process of alumina parts and sintering to produce porous material which is possible to use as a preform for infiltration by aluminium alloys.