Micro-Injection Molding and Debinding Behavior of Hydroxyapatite/Zirconia Bi-Materials Fabricated by Two-Component Micro-Powder Injection Molding Process

The micro-scale joining of two different materials using two-component micro-powder injection molding (2C-µPIM) is an intriguing technique. formation defects in bi-materials at processing stages makes this technique challenging. This study presents the fabrication defect-free bi-material micro-parts containing hydroxyapatite (HA) and 3 mol% yttria-stabilized zirconia (3YSZ) via 2C-µPIM. Critical powder volume concentrations (CPVCs) 61.7 vol% 47.1 were obtained for HA 3YSZ powders, respectively. Based on CPVCs, optimal loadings powders selected as 60 45 vol%, feedstocks prepared by separately mixing contents with low-density polyethylene (LDPE) palm stearin binders. displayed pseudoplastic behavior, lowest ranges viscosity a temperature 180 °C 157.1–1392.5 Pa·s 726.2–985.5 Pa·s, injected to produce green HA/3YSZ micro-sized components. It was found that solvent debinding 70 removed 60.6% binder from sample. In thermal stage, open channels formed sample’s debound contributed removal 93 95% system. When sintered 1300 °C, highest relative density 96.3% obtained. sintering operation revealed linear shrinkage between 13 17% micro-parts.