TY - JOUR
T1 - Microstructure, hardness and wear resistance of reactive sputtered Mo-O-N films on stainless steel substrate
AU - Sutou, Y.
AU - Komiyama, S.
AU - Sonobe, M.
AU - Ando, D.
AU - Koike, J.
AU - Wang, M.
N1 - Funding Information:
The authors wish to thank Mr. T. Toyoda for the help with the experimental work. This study was supported by the Industrial Technology Research Grant Program ( 11B14005d ) of the New Energy and Industrial Technology Development Organization (NEDO) of Japan in 2011 and partially supported by the Osawa Scientific Studies Grants Foundation in 2012.
Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/10/25
Y1 - 2015/10/25
N2 - The microstructure, hardness and wear property of Mo-O-N films deposited at different oxygen gas flow rates, fO2, on SUS304 stainless steel were investigated. The hardness, H, of the film increased with increasing fO2 in a low fO2 region (fO2≤0.05sccm) and reached a maximum value of about 32GPa because of grain refinement. With further increasing fO2, the H started to decrease due to the formation of the amorphous phase. Similarly, the effective Young's modulus, E*, of the film increased and then decreased with increasing fO2. It was found that the H/E* of the film could be enhanced by the addition of oxygen. The Mo-O-N film deposited at fO2=0.2sccm showed lower H and E*, but much higher H/E* than Mo-N film because of its considerably lower E*, which was due to the formation of a crystalline/amorphous mixed structure. The film deposited at fO2=0.2sccm with a crystalline/amorphous mixed structure showed the lowest μ in the present study and exhibited less frequent transverse cracking introduced by wear, as compared with that deposited at fO2=0.02sccm with a fine grain crystalline microstructure. These results indicate that the formation of the crystalline/amorphous mixed structure in the Mo-O-N film is effective to enhance the elasticity of the film without the associated large loss of the H, which leads to low μ and good wear resistance on the stainless steel substrate.
AB - The microstructure, hardness and wear property of Mo-O-N films deposited at different oxygen gas flow rates, fO2, on SUS304 stainless steel were investigated. The hardness, H, of the film increased with increasing fO2 in a low fO2 region (fO2≤0.05sccm) and reached a maximum value of about 32GPa because of grain refinement. With further increasing fO2, the H started to decrease due to the formation of the amorphous phase. Similarly, the effective Young's modulus, E*, of the film increased and then decreased with increasing fO2. It was found that the H/E* of the film could be enhanced by the addition of oxygen. The Mo-O-N film deposited at fO2=0.2sccm showed lower H and E*, but much higher H/E* than Mo-N film because of its considerably lower E*, which was due to the formation of a crystalline/amorphous mixed structure. The film deposited at fO2=0.2sccm with a crystalline/amorphous mixed structure showed the lowest μ in the present study and exhibited less frequent transverse cracking introduced by wear, as compared with that deposited at fO2=0.02sccm with a fine grain crystalline microstructure. These results indicate that the formation of the crystalline/amorphous mixed structure in the Mo-O-N film is effective to enhance the elasticity of the film without the associated large loss of the H, which leads to low μ and good wear resistance on the stainless steel substrate.
KW - Coatings
KW - Friction
KW - Hardness
KW - Microstructure
KW - Wear
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U2 - 10.1016/j.surfcoat.2015.08.047
DO - 10.1016/j.surfcoat.2015.08.047
M3 - Article
AN - SCOPUS:84944212335
SN - 0257-8972
VL - 280
SP - 1
EP - 7
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
ER -