Study of the influence of microwave sintering parameters on the mechanical behaviour of magnesium-based metal matrix composite

Abstract

In the present work, initially, the microwave sintering was used to fabricate a magnesium-based metal matrix composite (MgMMCs) especially Mg3Zn1Ca15Nb, at the same process parameters which were used to develop aforesaid material using conventional sintering. But, no improvement in the results were found, which may be owing to non-optimized parameters of microwave sintering. To carry out the optimization of microwave sintering parameters, first, the range of process parameters was obtained in this study. Sintering temperature (ST), heating rate (HR), and holding time (HT) were selected as sintering parameters. Additionally, the effects of these parameters on the ultimate compressive strength (UCS) as well as the sintered density of Mg3Zn1Ca15Nb were studied. After performing the compression test on the sintered samples (Ø10 × 15 mm2), an increment in both density and UCS was noted with the increase in sintering temperature and heating rate. Whereas sintering the sample above a certain period of holding time, the downward inclination of both UCS and sintered density was observed. The obtained UCS, as well as the density of microwave sintered samples were in the range of orthopedic implantable materials. The images obtained from scanning electron microscopy (SEM) affirmed the reduced porosity in the sintered samples as the heating rate increased. Additionally, a combined reduction in agglomeration, as well as cracks in the fabricated sample was observed by increasing sintering temperature. Energy-dispersive X-ray (EDX) study of the microwave fabricated Mg3Zn1Ca15Nb exhibited the presence of only parent elements in the fabricated sample. Also, no phase constituent was recorded in the fabricated sample, as confirmed by X-ray diffraction (XRD) spectra.