Effects of Molybdenum and Boron Additions of Fe-Based Metal Matrix Composites by Warm Compaction Method

<p>In this study, the mechanical behavior of an iron-based metal matrix composite (Fe–0.8C–2.0Cu–3.0Ni–XMo–YB [wt%], where X = 1.2 and 1.8; Y = 0.2 and 1.0) was investigated for potential use in gear manufacturing via powder metallurgy (PM). The composite materials were produced using the warm compaction method, followed by free sintering in a controlled argon gas atmosphere. The green compacts were obtained under a compaction pressure of 650 MPa at 160 °C, and subsequently sintered at 1050 °C, 1150 °C, and 1250 °C for 90 minutes.</p> <p>The influence of molybdenum (Mo) and boron (B) additions on the hardness, wear resistance, density, and microstructure of the composites was systematically examined. The worn surfaces of the sintered samples were characterized using scanning electron microscopy (SEM), and the elemental compositions were determined by energy dispersive spectroscopy (EDS). Furthermore, X-ray diffraction (XRD) analysis was performed to identify the phase constituents of the composites.</p> <p>Experimental results demonstrated that both hardness and wear resistance improved with increasing sintering temperature and higher Mo and B contents. Among all the samples studied, the composite produced at 1250 °C with 1.8 wt% Mo and 1.0 wt% B exhibited the highest hardness and superior wear resistance. This enhancement in mechanical performance is attributed to improved densification, formation of hard intermetallic phases, and more homogeneous microstructure development at elevated sintering temperatures.</p> <p>Overall, the findings of this study confirm that the warm compaction and sintering route is an effective manufacturing approach for producing Fe-based composites with optimized mechanical properties suitable for gear applications in the automotive and machinery industries.</p>