Effect of rice husk on fired ceramic shell strength

摘要

In recent years, ceramic shell mould for investment casting process is often associated to defects due to its brittle properties. The defects would originate from cracking mechanism yielded from the ceramic brittleness. In this work, the improvement of ceramic shell mould by reinforcement technique was studied and analyzed. Rice husk consisting high percentage of silica content with the ability to withstand high temperature during casting process was studied as the reinforcing component as to impede cracking mechanism. Higher Modulus of Rupture (MOR) value of ceramic shell reinforced by rice husk fiber as compared to the non-reinforced ceramic shell MOR value was obtained. Nonetheless, presence of the fused silica phase from rice husk fiber was also found to lead the formation of a new phase of zircon (ZrSiO4). These two factors were found to influence the ceramic shell composition and indirectly enhanced the ceramic shell strength performance.