Influence of Multi-Walled Carbon Nanotube Addition on the Hardness of NiAl-CNT and NiAl3-CNT Composites

Nickel aluminides have shown great potential as high temperature structural materials. In this study, two classes of nickel aluminide were reinforced with 0.5wt% MWCNTs. Starting powders of nickel, aluminium and MWCNTs were ball milled together using a two stage milling regime and consolidated by spark plasma sintering. The effect of MWCNT reinforcement on the hardness of two classes of nickel aluminide was investigated. Microhardness values revealed a lack of dependence on densification for the NiAl3 composites. The microhardness values of NiAl-CNT reduced with MWCNT addition whereas microhardness values of NiAl3-CNT increased with MWCNT addition.

Microstructure and Mechanical property of Porous Nickel aluminides Fabricated by Reactive Synthesis with Space Holder Powder

ABSTRACTEffect of Ni:Al blending ratio on porous structure of porous nickel aluminides fabricated through reactive synthesis with space holder particles were investigated. Fabricated porous nickel aluminides had large pores derived from NaCl space holder particles and small pores derived from reactions between Ni and Al. Porosity and size of the small pores increased with increasing Al content in the raw powder mixture. Compressive property of porous NiAl are also investigated. porous NiAl exhibited good energy-absorption properties with relatively high plateau stress, high plateau end strain, and relatively flat plateau stress. This study suggests the possibility of intermetallic-based porous materials as high-performance energy absorber.