Synthesis and Characterization of Nanocrystalline Ni-Cr-Al Alloy Powder

Abstract

The present study primarily focuses on the synthesis of nanocrystalline (NC) Ni-10Cr-10Al (wt%) alloy powder using a high energy ball mill. The composition of Ni-10Cr-10Al alloy was selected in such a way that the complete Al 2 O 3 layer would form on the outer surface of the NC Ni-Cr-Al alloy at high temperatures. For the synthesis of nanocrystalline alloy, powder metallurgy route was preferred in which the as-received powders of required composition were milled using planetary high energy ball milling for 20 h. The milled powders were collected from the mill at milling time of 0 h, 2 h, 5 h, 10 h, 15 h, and 20 h for studying the effect of milling on the powder. The milled powder was characterized using X-ray diffraction (XRD) and Differential Scanning Calorimetry (DSC). The crystallite size was calculated using the Williamson-Hall method and found to be near about 21 nm. Also, the effect of milling on the lattice parameter, micro-strain, dislocation density developed in the milled powder was analyzed using the XRD results. DSC was used to estimate the melting temperature of Ni-10Cr-10Al alloy. The characterization of milled powder suggests the successful formation of NC Ni-10Cr-10Al alloy powder using high-energy ball milling.