Co添加对Fe-Cr-Si合金组织与摩擦磨损性能的影响OA

With the continuous advancement of modern technology,the application domains of mechanical equipment are expanding progressively,and their operational environments are becoming increasingly complex.This has led to the failure of metallic components due to high loads and severe wear,necessitating the development of new wear-resistant alloy materials with excellent comprehensive properties.Fe-Cr-Si-based alloys have emerged as promising candidates for various harsh working conditions due to their outstanding wear resistance,corrosion resistance,and high-temperature stability.However,the thermodynamic incompatibility between the D03 and A2 phases in the Fe-Cr-Si system results in relatively poor room-temperature wear resistance,limiting their practical applications.The addition of Co not only improves the microstructural stability and strength of the alloys but also increases the activity of carbon,thereby enhancing the nucleation driving force for carbides,accelerating their nucleation rate,and promoting carbide formation.This process refines the grain structure and enhances the hardness of the material.Against this backdrop,the work aims to investigate the effect of Co content on the microstructure,morphological characteristics,and tribological properties of Fe-Cr-Si alloys to improve their wear resistance under ambient conditions.Two series of FeCrSi-based alloys with varying Co contents,Fe18Cr10SixCo and Fe18Cr10Si4CxCo(x=0,1,2,3,4)were prepared with an arc melting technique.The microstructures,microhardness,and wear performances of these alloys were systematically characterized through optical microscopy,scanning electron microscopy(SEM),microhardness testing,and friction-wear experiments.The results showed that the Fe18Cr10SixCo alloys exhibited a single-phase(Fe,Cr)solid solution structure.As the Co content increased,the microhardness of the alloys gradually increased,reaching a maximum of 349HV0.5 in the Fe18Cr10Si4Co alloy.However,both the friction coefficient and wear rate showed an upward trend with higher Co additions.The Fe18Cr10Si1Co alloy demonstrated the best wear resistance in this series,with a wear rate of 1.55×10-4 g/m and a friction coefficient of 0.495 3.The dominant wear mechanisms transitioned from a combination of oxidative,adhesive,and abrasive wear to severe spalling wear and abrasive wear as the Co content increased,leading to a gradual decline in wear resistance.In contrast,the Fe18Cr10Si4CxCo alloys consisted of dendritic(Fe,Cr)solid solutions and interdendritic Cr-rich carbides(Cr7C3 and Cr3C2).With the increasing Co content,the formation of interdendritic carbides was promoted,resulting in a continuous increase in alloy hardness,peaking at 479HV0.5 for the Fe18Cr10Si4C4Co alloy.Concurrently,both the friction coefficient and wear rate decreased,with the Fe18Cr10Si4C4Co alloy exhibiting the best wear resistance(wear rate:1.34×10-4 g/m;friction coefficient:0.505 1).The wear mechanism in this series saw a deepening of oxidative wear,while adhesive and abrasive wear effects were relatively reduced.In conclusion,the addition of Co effectively promotes the formation of carbides in Fe18Cr10Si4CxCo alloys.Both the hardness and wear resistance of these alloys increase gradually with higher Co content,highlighting the crucial role of Co in optimizing the microstructure and tribological properties of Fe-Cr-Si-based materials for ambient applications.These findings provide valuable insights for the design and development of high-performance wear-resistant alloys in various industrial fields.