Nickel-aluminide cladding on a steel substrate using dual wire arc additive manufacturing

In this study the nickel-aluminide intermetallic cladded on AISI 1010 steed using dual wire arc process. The nickel-aluminide is fabricated in situ through an arc provided by a gas tungsten arc welding process and changing aluminum wire feeding rate. The research findings reveal that at a constant Ni wire feeding rate of 450 mm/min, by decreasing the Al wire feeding rate lower than 800 mm/min, the instability of the melt pool prevents the formation of a uniform deposit on the substrate. Although deposition has been done at an Al wire feeding rate higher than 1600 mm/min, transverse cracks have formed in the clad layer. Increasing the aluminum wire feeding rate from 1000 to 1400 mm/min decreases the dendritic arm size from 9.2 ± 0.1 to 4.1 ± 0.3 μm. Although unreacted nickel is visible in the microstructure at the Al wire feeding rate of 1000 mm/min, at a high feeding rate (1400 mm/min), most of the microstructure contains AlNi and Ni 3 Al intermetallic compounds. With the rise in Al wire feeding rate from 1000 to 1400 mm/min, both yield strength and ultimate tensile strength increase from 521.45 ± 14.16 to 620.89 ± 16.08 MPa and from 762.11 ± 19.89 to 855.65 ± 21.54 MPa, respectively. Intriguingly, the clad layer's tensile toughness decreases from 26.51 ± 2.43 to 18.32 ± 2.56 MJ m −3. By increasing the wire feeding rate from 1000 to 1400 mm/min, the wear rate at room temperature, 500 °C, and 800 °C increases by 61.2, 45.7, and 44.3%, respectively.