Publication: Effect of sintering temperature on the properties of magnesium substituted biphasic calcium phosphate
Date
2020-05-01
Authors
Marahat, Muhammad Hanif
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Abstract
Biphasic calcium phosphate (BCP) is a bioceramic material which are known to have two distinguish phases which is hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP). The aim of this research is to improve the limitation in mechanical properties of BCP by the addition of 0.025 wt% of Mg. The addition of Mg was able to increase the densification of BCP by stabilizing the β-TCP phase and delay the formation of α-TCP at high sintering temperature. Therefore, this study emphasizes on the effect of Mg substitution on BCP upon densification through sintering process. BCP and MgBCP powder was synthesized via wet precipitation method using the ratio of (Ca+Mg)/P 1.61. The obtained as-synthesized powder was pressed in pellet shape and sinter at temperature 900oC, 1000oC and 1100oC. The analysis is separated into two part which covers the unsintered as-synthesized powder and sintered pellet. The as-synthesized powder shows that Mg substitution improved the crystallinity peak from XRD analysis. For sintered pellet, the result for porosity of BCP have shown that the porosity of BCP have decreases from 40% at 900oC to 25% at 1100oC respectively. The trend also decreases as Mg was added, from 39% (900oC) to 22% (1100oC). Moreover, the result for mechanical testing shows that the MgBCP pellet is having higher mechanical strength compared to BCP pellet. The highest compressive strength for BCP pellet is at 5.02 MPa and MgBCP is at 9.41 MPa. The same trend with Vickers hardness testing which record BCP (0.82 GPa) and MgBCP (0.93 GPa). Overall trend shows that sintering at 1100oC gives better mechanical strength. Moreover, in term of biological analysis, MgBCP pellet gives more formation of apatite layer on its surface under FESEM observation due to more dissolution process for apatite to growth.