The Effect Of SiC Content And Particle Size On Microstructures And Wear Properties Of SiC/Fe-3Cu-C Material

Abstract:SiC/Fe-3Cu-C materials were prepared by powder metallurgy under sintering condition of1100℃,1.1MPa, the effect of SiC content on material density, structure, mechanical properties, friction and wear properties were studied. SiC/Fe-3Cu-C material SiC/Fe-3Cu-0.5Mo-C material were prepared, with SiC particle sizes of6.5μm,9.5μm,19.5μm and47.0μm respectively. The effect of SiC particle size on density, structure, mechanical properties, friction and wear properties of both materials were studied comparatively. Interfacial reaction between SiC particles and the iron matrix was investigated. Element analysis was conducted in the SiC particles, matrix-particle interface and the matrix. Wear mechanism and fracture mechanism were also studied. The results showed that:The structure of Fe-3Cu-C matrix is lamellar pearlite. Small amount of SiC addition can make pearlite lamellar spacing smaller. When0.75wt%SiC particles are added, the matrix consists of pearlite and mesh cementite. With increasing SiC content, the density of SiC/Fe-3Cu-C material decreases, porosity increases, hardness decreases at the beginning and then increases. Combined analysis of mechanical properties and wear test results, suggests that the wear resistance is improved significantly without reducing the mechanical properties badly when adding0.5wt%SiC particles. When the content of SiC particles reaches2wt%, the mechanical properties and wear resistance are significantly reduced.The matrix of Fe-3Cu-0.5Mo-C materials is pearlite and bainite. Mesh cementite also appeared after adding SiC particles. SiC/Fe-3Cu-C material exhibits best wear performance and good mechanical properties when the SiC particle is9.5μm. SiC/Fe-3Cu-0.5Mo-C materials exhibits best wear performance and good mechanical properties with SiC particle size of19.5μm,which shows that improved matrix contributes to increasing SiC particle size in the iron-based alloy, thus improving the wear resistance of material. SiC particles are homogenously distributed in SiC/Fe-3Cu-C material and SiC/Fe-3Cu-0.5Mo-C material. Unreacted SiC particles exist in the matrix and their surrounding microstructure is still pearlite. No obvious interface products appear and good interface bonding between material matrix and SiC particles is obtained.Elemental analysis shows that Si to C ratio is3:1and2:1respectively in SiC particle both in SiC/Fe-3Cu-C material and SiC/Fe-3Cu-0.5Mo-C material. Conclusion can be drawn that interfacial reaction between SiC and Fe can be reduced with adding alloying elements Mo.