Effect of ZnO addition on the purity and densification of forsterite ceramic

Forsterite was found to the next potential candidate for bone implant application due to its superior mechanical properties as compared to the commonly used hydroxyapatite (HA). Various methods including two-step sintering and improvise synthesis method were introduced in hope to further improve the mechanical properties of forsterite. In this work, sintering additives, particularly zinc oxide (ZnO), was introduced into forsterite to provide enhancement on the densification of forsterite at lower sintering temperature. Forsterite powder was synthesized via solid-state reaction method with heat treatment at 1000 degrees C for 2 hours with 10 degrees C/min ramping rate. Addition of ZnO was conducted using milling process with composition of 0.5 wt% and 1.0 wt% ZnO. Green bulk samples were prepared prior to sintering process at 1200 degrees C to 1500 degrees C for 2 hours with 10 degrees C/min ramping rate. Characterization was conducted in terms of phase stability and densification of forsterite with morphology examination to observe the grain surface of all samples. It was revealed that the addition of ZnO showed a more superior densification as compared to the undoped samples at all sintering regime studied with a maximum relative density obtained at 97.7% by 0.5 wt% ZnO doped sample sintered at 1500 degrees C.