Towards a high strength ductile Ni/Ni3Al/Ni multilayer composite using spark plasma sintering

This paper is an attempt to develop an innovative high strength and ductile Ni/Ni3Al/Ni multilayer composite, using spark plasma sintering (SPS). Ni3Al powders were first synthesized by mechanical alloying of elemental pure Ni and Al powders. The synthesized intermetallic powders were then mixed with Ni powders in a way that a Ni/Ni3Al/Ni multilayer composite can be achieved. Scanning electron microscope, optical microscope, energy dispersive X-ray spectroscopy (EDS), microhardness, and shear punch tests were used to characterize microstructure and mechanical properties of the synthesized composite. Results show that a rather sharp interface with a perfect metallurgical bonding has formed at the Ni/Ni3Al joint. The synthesized multilayer composite has a perfect combination of strength and ductility. The maximum shear strength of Ni/Ni3Al/Ni multi-layer composite is significantly higher than that of Ni3Al, while its ductility is comparable to that of pure Ni.