A novel manufacturing process for intermetallic thin-walled components: Forming and hot pressing of thin-walled laminates prepared by laying/winding metal foil strips

Abstract

To address the challenge of manufacturing NiAl intermetallic thin-walled components, an integrated manufacturing process using the preform prepared by laying/winding of metal foil strips was proposed. This method entails the initial fabrication of a stacked foil preform via the laying/winding of metal foil strips, followed by pre-sintering to prepare a laminated preform. Subsequently, precise shaping is achieved through hot bulging of the laminated preform, while the NiAl intermetallic phase is obtained through reaction synthesis of Ni and Al foils under hot pressing. The microstructure of Ni/Al/Ni laminated preforms under varied sintering parameters and different laminating methods were analyzed. Additionally, the deformation behaviors of these preforms at both room and high temperatures were investigated via tensile tests and bulge tests. Results show: (1) The micro-cracks and Ni-Ni interface delamination occurred in the brittle Ni2Al3 layer of the laminated preform. The deformation capability of laminated plates decreased as the thickness of the brittle Ni2Al3 layer increased with sintering time. (2) Tiny gaps between foils due to laying path and foil size deviations, causing reduced deformability and fractures when the tensile direction was perpendicular to these gaps. (3) These gaps and micro-cracks can be progressively eliminated through hot pressing sintering processes. The findings verify the preliminary feasibility of the proposed novel manufacturing process and provide a novel solution for manufacturing NiAl intermetallic thin-walled components.