期刊
JOURNAL OF ALLOYS AND COMPOUNDS
卷 675, 期 -, 页码 22-30出版社
ELSEVIER SCIENCE SA
DOI: 10.1016/j.jallcom.2016.03.109
关键词
NbNx coating; Magnetron sputtering; Microstructure; Mechanical properties; Oxidation resistance
资金
- JK Program of Fujian Province [JK2014034]
- Program of Xiamen University of Technology [YKJ13006R]
Mechanical properties and oxidation resistance are of importance for the NbNx coatings as used in cutting and forming tools. In this study, the NbNx coatings were deposited by magnetron sputtering at nitrogen partial pressure ranging from 0 to 40%. The chemical and phase compositions, morphologies, mechanical properties and oxidation behaviors of the NbNx coatings were investigated by electron probe microanalysis, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, scanning and transmission electron microscopy, and nanoindentation measurements. The results reveal the composition evolution of the NbNx coatings as alpha-Nb (0%), beta-Nb2N (5%), a mixture of beta-Nb2N and delta-NbN (10%), and delta-NbN (20-40%). The single phase coatings exhibit columnar structure while the mixed phases coating shows nano-composite structure. Compared with the single phase delta-NbN coatings (21.6 +/- 0.8 -28.0 +/- 1.2 GPa), higher hardness of the single phase beta-Nb2N coating (30.9 +/- 1.0 GPa) is due to the higher covalent character and much finer grains. The maximum hardness reaches 33.3 +/- 1.5 GPa for the nano-composite coating with mixed phases of beta-Nb2N and delta-NbN. The oxidation results demonstrate that the activation energies are 219.3 and 192.3 kJ/mol for the Nb2N and NbN coatings respectively. Non-protective Nb2O5 scales with cracks and pores result in poorer oxidation resistance of the NbN coating in comparison to the Nb2N coating. (C) 2016 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据