This study applied plasma transferred arc (PTA) welding to fabricate hard cladding layers by using nickel-based superalloy (NCR7) and niobium carbide (NbC) powders as filler material. The resultant composite claddings were coated onto ductile iron and then analyzed to understand the effect of different quantities of NbC on the solidification structures of the cladding layers and on the characteristics of the interface between the cladding layers and the ductile iron. Cutting tests were also conducted to assess the morphology and mechanism of flank wear on PTA NbC/NCR7 composite cladding tools. The results revealed that the cladding specimens’ microstructures comprised a mixture of dendrites and interdendritic eutectics along with a considerable quantity of carbides (MC, M7C3, and M23C6) scattered within the γ-Ni matrix. Incorporating considerable NbC carbide enhanced the claddings’ surface hardness, but it had a limited effect on improving the flank wear on the turning tools. The flank wear on the composite cladding tools intensified as the NbC content was increased. The wear behavior, defined by brittle fractures and stripped NbC particles, led to a decline in turning tool performance. Accordingly, the Ni-based alloy composite cladding with larger NbC particles appears more suitable for sliding or erosion applications under normal stress conditions.

In this study, electrically conductive PANDB/γ-Al₂O₃ core–shell nanocomposites were synthesized by surface modification of γ-Al₂O₃ nanoparticles using polyaniline doped with dodecylbenzene sulfonic acid. The PANDB/γ-Al₂O₃ core–shell nanocomposites were synthesized by in situ polymerization. Pure PANDB and the PANDB/γ-Al₂O₃ core–shell nanocomposites were characterized using Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, and measurement of a four-point probe. The conductivity of the PANDB/γ-Al₂O₃ core–shell nanocomposite was about 0.72 S/cm when the weight ratio of aniline/γ-Al₂O₃ was 3/1. The results showed that the conductivity of the PANDB/γ-Al₂O₃ core–shell nanocomposite decreased with increasing amounts of γ-Al₂O₃ nanoparticles. The transmission electron microscopy results indicated that the γ-Al₂O₃ nanoparticles were thoroughly coated with PANDB to form a core–shell structure. Transmission electron microscopy and field emission scanning electron microscopy images of the conductive PANDB/γ-Al₂O₃ core–shell nanocomposites also showed that the thickness of the PANDB layer decreased as the amount of γ-Al₂O₃ was increased.