Development of Mg based biomaterial with improved mechanical and degradation properties using powder metallurgy

In the present work, biocompatible materials such as niobium (Nb), zinc (Zn) and calcium (Ca) have been blended with magnesium (Mg) to develop a novel biomaterial (BM) with improved mechanical and corrosion resistant properties. Powder metallurgy (PM) technique was used to fabricate Mg based BM. The powder of all aforementioned materials were mixed homogenously in specific quantities to create a uniform composite component. In order to analyse the influence of process parameters on the mechanical properties of the fabricated part, experiments were performed considering central composite design (CCD). The effect of powder metallurgical parameters namely percentage Nb, compaction pressure, heating rate, sintering temperature and soaking time on the ultimate compressive strength (UCS) and sintered density was studied in the present study. It was found that the UCS and sintered density increased with increase in compaction pressure, heating rate and sintering temperature. The results also revealed that the increase in soaking time and percentage Nb, increased sintered density and UCS to a certain limit. Subsequent increase in these two parameters, sintered density and UCS decreased. Scanning electron microscopy (SEM) images of the fabricated samples showed reduction in porosity with the increase in heating rate. Moreover, X-ray diffraction (XRD) results revealed that no other phase or impurities were found during sintering of Mg based BMs. The optimum process parameters were obtained to develop Mg based BM for maximum UCS and sintered density. Furthermore, the Mg based BM samples fabricated at optimum process parameters were used for corrosion testing in simulated body fluid (SBF) solution at a temperature of 37±0.5°C. The Mg based BM yielded improved mechanical properties with reduced corrosion rates as compared to pure Mg.