Fabrication of magnesium-boron carbide metal matrix composite by powder metallurgy route: Comparison between microwave and spark plasma sintering

Microwave and spark plasma sintering processes were used to produce magnesium-B4C metal matrix composites by powder metallurgy route. Magnesium powder with 5 wt% B4C in ethanol media was blended in a high-energy ball mill for 10 min. The sintering process was performed at 500° and 670 °C using spark plasma sintering and microwave furnace, respectively. XRD investigations revealed the crystallization of MgB2 and Mg2C3 compounds during both sintering processes. The mechanical examinations showed higher bending strength (191 ± 15 MPa) and microhardness (92 ± 7 Vickers) of SPS samples rather than microwave samples. FESEM images demonstrated uniform distribution of B4C reinforcements at grain boundaries of metallic matrix. The MAP analysis of SPS samples approved the formation of new compounds as a result of the reaction between magnesium and B4C.