LUO Xubin ¹, LIU Jixuan ¹, JI Dongdong ¹, XIAO Yong ¹, HAN Zhilin ², LIANG Yongcheng ², ZHANG Guojun ¹

(1. State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Institute of Functional Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201600, China; 2. College of Science, Donghua University, Shanghai 201600, China)

Abstract: ZrN1−x (x = 0–0.3) ceramics with different nitrogen vacancy concentrations were prepared by using reactive spark plasma sintering, with ZrN and ZrH2 powders as raw materials. With increasing concentration of nitrogen vacancy from 0 to 0.3, relative density of the samples sintered at 1600 ℃ increased from 90.5% to 99.6%, while the second phase of ZrO2 gradually dissolved into the matrix, the oxygen content of the matrix phase increased from 0.03 at.% to 10.04 at.%, the average grain size increased from 3.12 μm to 33.13 μm and the lattice constant first increased and then decreased. The lattice constants of ZrN1.0, ZrN0.9, ZrN0.8 and ZrN0.7 are 4.5769 Å, 4.5806 Å, 4.5834 Å and 4.5799 Å, respectively. The Young’s modulus of ZrN1−x decreased gradually with increasing concentration of nitrogen vacancy, while the Young’s modulus of ZrN1.0-1700 and ZrN0.7-1600 with similar relative density were 365 GPa and 300 GPa, respectively. The experimental lattice constant and Young’s modulus are consistent with the first-principles calculations results.

Key words: ZrN ceramics; nitrogen-vacancy concentration; mechanical properties; first-principles calculations