Synergetic enhancement of strength and ductility for titanium-based composites reinforced with nickel metallized multi-walled carbon nanotubes

Poor ductility of titanium matrix composites with medium/high-strength reinforced with carbonaceous nanomaterials (eg., graphene, carbon nanotubes etc.), has seriously restricted their wide-range engineering and practical industry utility. Herein, we propose a new methodology to significantly and simultaneously enhance both ductility and tensile strength of the titanium matrix composites. We ball milled Ti-6Al-4V (TC4) powders with in-situ chemically synthetized Ni decorated multi-walled carbon nanotubes (i.e MWCNTs@Ni), and then sintered the composites powders using spark plasma sintering (SPS). We achieved both a significant balanced between superior strength and increased ductility of the composite using the MWCNTs@Ni nanopowders. The enhanced strength in composites is mainly attributed to the interfacial structures for effectively enhanced load transfer capability between MWCNTs@Ni and Ti matrix, e.g., the formation of coherent/semi-coherent interfaces among interfacial phases Ti2Ni, TiC and Ti matrix. Furthermore, we applied the dislocation theory to reveal the toughening mechanisms of MWCNTs@Ni in the MWCNTs@Ni/TC4 composites. This study provides a new method-ology of fabricating metal matrix composites (reinforced with carbon based nanomaterial) with both high strength and good ductility. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

A new methodology is proposed to enhance both ductility and tensile strength of titanium matrix composites by ball milling Ti-6Al-4V powders with Ni decorated multi-walled carbon nanotubes and then sintering the composites powders using spark plasma sintering. The enhanced strength in composites is mainly attributed to the interfacial structures for effectively enhanced load transfer capability between MWCNTs@Ni and Ti matrix. This study provides a new methodology of fabricating metal matrix composites with both high strength and good ductility.