Effect of mechanical alloying on the structure and properties of NbCr2 Laves phase fabricated by hot pressing

NbCr2 Laves phase intermetallics has been successfully made with mechanically alloyed powders with nominal compositions Cr—33.3 at.% Nb by hot pressing (HP). The effect of mechanical alloying (MA) on the structure and the properties of hot-pressed alloy has been investigated by X-ray diffraction, scanning electron microscopy, and bending test, etc. The results show that the NbCr2 Laves phase prepared from milled powders exhibits high strength and low density in comparison with one prepared from elemental powders. The high density of defects brought during MA and deficiently eliminated by following HP led to the high hardness and low density. Fine grains and dispersion of fine precipitation caused by MA are related to the improvement of strength of alloy.

Graphical AbstractLaves phase NbCr2 was little formed but the peaks of Nb and Cr much appear after hot pressing for elemental powders. For the milled elemental powder, however, there were many peaks of Laves phase NbCr2 in the X-ray diffraction patterns after hot pressing. And the fine grain action by mechanically alloying can be observed from curve (a) in comparison with curve (b).Figure optionsDownload full-size imageDownload as PowerPoint slide