Injection molding process and microstructure of ceramic micro-structured part

ZrO ₂ micro-structured parts were fabricated with powder micro injection molding process. The forming process of ceramic micro-structured part, such as feedstock preparation, injection parameters and sinter process and the effect of these parameters on the microstructure was analyzed. Experimental results indicate that the relative density and microhardness of the micro-structured part sintered under 1500°C for 2 h are 98.5% and 13.75 GPa, respectively. Observation results of scanning electron microscope (SEM) reveal that higher mold temperature and injection pressure contribute to the improvement of filling performance and microstructure. Increasing sintering temperature can induce the densification of micro-structured part, while resulting in the overgrowth and non-homogeneity of grain. Good surface roughness of sintered ceramic micro-structured parts can be obtained by using sub-micron ZrO ₂ powder. Observation results of confocal laser scanning microscope reveal that the surface roughnesses of green and ceramic micro-structured parts are 0.33 μm and 0.28 μm, respectively. Moreover, the shrinkage of micro-structured parts decreases with the increase of powder content in feedstock, which is favorable to precise control of the micro-structured parts.