Resistance spot welding of Nimonic 263 nickel-based superalloy: microstructure and mechanical properties

Abstract

This paper addresses the metallurgical and mechanical response of Nimonic 263 nickel-based superalloy to resistance spot welding. Solidification structure of the fusion zone is described in terms of dendrite arm spacing, segregation behaviour and secondary carbide formation in the inter-dendritic area. The heat affected zone is featured by negligible grain growth and constitutional liquation of primary (Ti, Mo)C carbide present in the initial microstructure of the base metal. Mechanical behaviour of the welds was characterised by interfacial to pullout failure mode transition, peak load and energy absorption of the joints during the tensile-shear loading. The fusion zone size and the electrode indentation depth are the key factors controlling peak load and energy absorption of the Nimonic 263 resistance spot welds.

Critical review on fusion welding of magnesium alloys: metallurgical challenges and opportunities

“…The geometry of the dendrites, dendrite arm spacing (DAS) in terms of primary DAS and secondary DAS, is controlled by the solidification time, which is inversely proportional to the cooling rate [28,43]. The faster cooling rate leads to the formation of finer dendrite arm spacing [43,44]. This can be achieved by using lower heat input or employing a high power density heat source (e.g.…”

“…The microstructure development during solidification of Mg alloy fusion zone is controlled during two interlinked stages: Formation of Mg-rich primary phase dendrites: This first stage controls the grain structure, which will be discussed in detail in the next section, and the geometry of the dendrites. The geometry of the dendrites, dendrite arm spacing (DAS) in terms of primary DAS and secondary DAS, is controlled by the solidification time, which is inversely proportional to the cooling rate [28, 43]. The faster cooling rate leads to the formation of finer dendrite arm spacing [43, 44].…”