Effect of Mechanical Alloying and Sintering on Phase Transformation, Microstructural Evolution, Mechanical Properties and Density of Zr-Cr Alloy

The purpose of present research was production ofZr-based alloy as the nuclear fuel cladding by mechanical alloying (MA) and sintering process. Firstly, Zr and Cr powders were mechanically alloyed to produce the refractory and hard Zr-10 wt% Cr alloy, and then, the powder mixtures were consolidated by press and following sintering at temperature of 800˚C min. The phase evolution, microstructural changes, microhardness, and density of the Zr-10 wt% Cr alloy were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness measurement, and the Archimedes method. The results showed that the MA increased the solid solubility of the immiscible powders of Cr and Zr; therefore, the Cr atoms were completely dissolved in the Zr lattice after 24 h of the milling time and the nanostructured Zr(Cr) solid solution was obtained with the high microhardness value of about 491 Hv. Also, the results of the density measurement indicated that the resulted density was close to 98% of the theoretical density.