Investigation on mechanical properties of cold sprayed Ni–Ni₃Al composites

Abstract

This study investigates the microstructural and mechanical characteristics of the Ni–Ni₃Al composites fabricated by cold spraying. Investigations were conducted on pure Ni samples as well as composites consisting of 80 vol.-%Ni and 20 vol.-%Ni₃Al. The results of a variety of hardness tests such as Vickers, Knoop, and nano-indentation are reported in this study. Furthermore, this study examines the application of analytical models to calculate the elastic modulus of coating materials from hardness test results. The validity of the obtained results was examined by performing impulse excitation (resonant frequency) test on all samples. A similar study was also performed on the same materials produced by the powder metallurgy (P/M) technique for the purpose of comparison. The reinforced samples exhibited better mechanical properties compared to the unreinforced ones regardless of the fabrication technique. The cold sprayed sample exhibited higher strength and density compared to the P/M processed ones.

Keywords:

• Cold spraying
• Intermetallics
• Metal matrix composites
• Mechanical properties
• Microstructural characterisation
• Powder metallurgy

Acknowledgements

The authors would like to thank NDSU Electron Microscopy Center, for the valuable help on microstructural characterisation using SEM. The authors also wish to thank IMCE, Belgium for Resonant Frequency tests.