کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1448226 | 988668 | 2010 | 11 صفحه PDF | دانلود رایگان |
TiBCN nanocomposite coatings were deposited in a closed field unbalanced magnetron sputtering system using pulsed magnetron sputtering of a TiBC compound target with various Ar/N2 mixtures. TiBCN coatings were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, nanoindentation, Rockwell C indentation and ball-on-disk wear tests. The coatings with a nitrogen content of less than 8 at.% exhibited superhardness values in the range of 44–49 GPa, but also showed poor adhesion and low wear resistance. Improvements in the coating adhesion, H/E ratio and wear resistance were achieved together with a decrease in the coating hardness to 35–45 GPa as the N content in the coatings was increased from 8 to 15 at.%. The microstructure of the coatings changed from a nano-columnar to a nanocomposite structure in which 5–8 nm nanocrystalline Ti(B,C) and Ti(N,C) compounds were embedded in an amorphous matrix consisting of BN, free carbon and CN phases. With a further increase in the N content in the coatings to levels greater than 20 at.%, the inter-particle spacing of the nanocrystalline compounds increased significantly due to the formation of a large amount of the amorphous BN phase, which also led to low hardness and poor wear resistance of the TiBCN coatings.
Journal: Acta Materialia - Volume 58, Issue 5, March 2010, Pages 1554–1564