The Influence of Different Phases on the Microstructure and Wear of Inconel-718 Surface Alloyed with AlCuNiFeCr Hard Particles Using Plasma Transferred Arc

In this study, Al, Cu, Ni, Fe and Cr powders with equivalent molar ratio were taken and mechanically ball milled. Ball-milled AlCuNiFeCr was coated on the cleaned degreased Inconel-718 base material. Plasma Transferred Arc (PTA) method was adopted to get alloyed the coated particles on the base material. Phase formation, structural, elemental distribution in the alloyed region, enhancement of microhardness, wear behavior and wear mechanism of surface-modified Inconel-718 material were investigated. Result showed that the PTA treated sample possessed more BCC phases and large value of lattice distortion compared to the ball-milled powder. The top of the alloyed region mainly contained equiaxed crystals, inter-connected columnar dendrites, isolated inter-dendrites, secondary dendrite arm structure and Widmanstatten structure. The dendrites in the near interface region of the PTA alloyed region were gradually refined, became long and thin strips. The microhardness value of substrate, interface and alloyed surfaces were 348 ± 17.52 HV_0.2, 643 ± 32.92 HV_0.2 and 881 ± 44.64 HV_0.2, respectively. The specific wear rate of PTA alloyed coatings was 0.0531 × 10^–3 mm³/Nm which was less than that of Inconel-718 substrate (0.1711 ×10^–3 mm³/Nm). The contact of the pin to the disc surface increased with the increase of the applied load from 40 N to 60 N. The COF of treated samples and Inconel-718 substrate at 40 N applied load with 1 m/s velocity were 0.28 and 0.46, respectively. Similarly, The COF at 60 N applied load with 0.8 m/s velocity were 0.42 and 0.81, respectively. Lower surface roughness was noticed on the treated worn-out samples due to less wear rate compared to the substrate material.