Effects of Niobium Carbide Additions on Ni-Based Superalloys: A Study on Microstructures and Cutting-Wear Characteristics through Plasma-Transferred-Arc-Assisted Deposition

Abstract

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.

Brazing Temperature Effects on the Microstructure and Mechanical Properties of Ti-45Al-8Nb Joints Using TiZrCuNi Amorphous Interlayer

“…Currently, heat-resistant steel, Ti-based alloys, Fe-based alloy, and Ni-based alloys are used in the aerospace field, as they possess multiple properties such as hot oxidation and corrosion resistance, and remarkable mechanical properties [1,2]. The properties of these alloys affect engine properties' parameters such as engine thermal efficiency and thrust-to-weight ratio.…”