A modified Fe–Ni alloy coating in pure iron combined of surface mechanical attrition treatment and spark plasma sintering approach

Abstract

To overcome the shortage of long processing time, high energy consumption, and complex controlling in fabricating Fe–Ni alloy coating, this paper was modified Fe–Ni alloy coating based on the mechanical alloying, electrodeposition, laser cladding and DC arc plasma method. Here, Surface Mechanical Attrition Treatment (SMAT) had been chosen as a pre-treatment to fabricate uniform Fe–Ni alloy coating by Spark Plasma Sintering (SPS). After the well-designed coating approach of SMAT + SPS, a homogeneous and continuous Fe–Ni alloy coating was fabricated on a pure iron plate. During study of the effect of SMAT and the subsequent process of SPS on microstructure and mechanical properties of Fe–Ni alloy coating, a valid set of process parameters were investigated. The results show that the thickness of Fe–Ni interface layer was enhanced significantly by SMAT. In comparison, the depth on the SMAT-sample was approximately twice as thick as on the untreated coarse-grained (CG) sample. The relative densification, microhardness and friction and wear performance are significantly related to the sintering temperature, which also affects the microstructure of interface between iron matrix and alloy coating. It has been evidently proved that, the sintering temperature just within 800–900 °C, the optimum performance Fe–Ni alloy coating on the SMATed iron matrix could be obtained, which has higher density, better wear resistance and tighter bonding.