Dependence of Surface Conductivity on Preferred Orientation of Tin Film for Ti Bipolar Plate

Austenitic 349 stainless steel was nitrided in an NH3 plasma. A low interfacial contact resistance was obtained with the nitrided steel. Glancing angle X-ray diffraction suggests that the nitrided layer is very thin and possibly amorphous. X-ray photoelectron spectroscopy (XPS) studies show that the nitrided layer is composed of mixed oxides and nitrides of Fe3+ and Cr3+. Contaminations of V and Sn were also observed, though their influence on the as-nitrided surface conductivity is not clear. The nitrided samples were investigated in a simulated polymer electrolyte membrane fuel cell (PEMFC) environment, and showed excellent corrosion resistance. The XPS depth profile indicated that the passive film, which formed on the plasma-nitrided steel in the PEMFC anode environment, is composed of mixed oxides and nitrides, in which chromium oxide/nitride dominates the surface chemistry. No V or Sn was detected on the surface after the polarization tests. For the PEMFC bipolar plate application, nitridation in NH3 plasma is a promising surface treatment approach, though more research is needed to investigate the influence of the plasma density and substrate bias on the surface conductivity and performance of the nitrided steel in PEMFC environments.

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Electrochemical behaviour and surface conductivity of niobium carbide-modified austenitic stainless steel bipolar plate

Journal of Power Sources ◽

10.1016/j.jpowsour.2013.08.025 ◽

2014 ◽

Vol 246 ◽

pp. 775-782 ◽

Cited By ~ 41

Author(s):

Lixia Wang ◽

Juncai Sun ◽

Bin Kang ◽

Song Li ◽

Shijun Ji ◽

...

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Electrochemical Behaviour ◽

Niobium Carbide ◽

Bipolar Plate ◽

Surface Conductivity

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Characterisation of Titanium Nitride Thin Films Deposited by Cathodic Arc Plasma Technique on AISI D6 Tool Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.498-499.717 ◽

2005 ◽

Vol 498-499 ◽

pp. 717-721 ◽

Cited By ~ 2

Author(s):

R.A. Vieira ◽

Maria do Carmo de Andrade Nono

Keyword(s):

Thin Film ◽

Substrate Temperature ◽

Tool Steel ◽

Preferred Orientation ◽

Interface Region ◽

Tin Films ◽

Tin Film ◽

Electron Image ◽

Steel Substrates ◽

Cathodic Arc

TiN thin film has been produced on the surface of AISI D6 tool steel by using a titanium interlayer. In this work, the morphology, the microstructure and interface depth profile of TiN films deposited at two substrate temperatures (220 oC and 450 oC) in the coating process are presented and discussed. The AISI D6 tool steel substrates were coated with titanium thin film as the underlayer and with TiN thin film as the top layer. They were deposited by conventional cathodic arc process. The surfaces of TiN films were observed by scanning electron microscopy (SEM). The microstructure of these samples was analysed by X-ray diffractometry (XRD). The influence of the substrate temperature on the TiN film-Ti film-AISI D6 interface region were investigated by energy dispersive spectrometry (EDS) and its cross section were observed using backscattered electron image (BEI). The results showed that TiN films deposited at 220 oC formed a film of strongly (111) preferred orientation, while in 450 oC formed a film of (111) and (220) preferred orientation. The thickness of the TiN films increased with increasing substrate temperature. The results show that the interface region of the TiN film-Ti film-AISI D6 substrate system was significantly improved when higher substrate temperature during deposition is used.

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Two critical thicknesses in the preferred orientation of TiN thin film

Journal of Materials Research ◽

10.1557/jmr.1998.0174 ◽

1998 ◽

Vol 13 (5) ◽

pp. 1225-1229 ◽

Cited By ~ 21

Author(s):

U. C. Oh ◽

Jung Ho Je ◽

Jeong Y. Lee

Keyword(s):

Strain Energy ◽

Strong Dependence ◽

Middle Layer ◽

Bottom Layer ◽

Columnar Structure ◽

Preferred Orientation ◽

Cross Sectional ◽

Tin Film ◽

Tin Thin Films ◽

The Cross

The preferred orientation of the TiN film grown by sputter-deposition was studied by the cross-sectional TEM. The preferred orientation was changed from the (200) through the (110), and then finally to the (111) with the film thickness. The cross-sectional microstructure also shows that the film consists of three layers which are all columnar structure. The (111) preferred orientation was observed in the top layer, and the (110) in the middle layer, and finally the (200) in the bottom layer. It is very surprising that the (110) preferred orientation could be observed in a medium thickness region and there are two kinds of critical thicknesses. These results surely show the strong dependence of the change in the preferred orientation on the strain energy in TiN thin films.

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Effect of microstructure of TiN film on properties as bipolar plate coatings in polymer electrolyte membrane fuel cell prepared by inductively coupled plasma assisted magnetron sputtering

Thin Solid Films ◽

10.1016/j.tsf.2013.03.115 ◽

2013 ◽

Vol 544 ◽

pp. 224-229 ◽

Cited By ~ 9

Author(s):

Kai Feng ◽

Zhuguo Li

Keyword(s):

Fuel Cell ◽

Magnetron Sputtering ◽

Polymer Electrolyte ◽

Inductively Coupled Plasma ◽

Polymer Electrolyte Membrane ◽

Bipolar Plate ◽

Inductively Coupled ◽

Electrolyte Membrane ◽

Tin Film ◽

Effect Of Microstructure

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Study of the effect on conductivity and its uniform distribution in injection molded composite polymer bipolar plate

e-Polymers ◽

10.1515/epoly.2007.7.1.1676 ◽

2007 ◽

Vol 7 (1) ◽

Author(s):

Chen Shia-Chung ◽

Shih Ming-Yi ◽

Lin Yi-Chang

Keyword(s):

Flow Direction ◽

Mold Temperature ◽

Bipolar Plate ◽

Surface Conductivity ◽

Temperature Control System ◽

Melt Flow ◽

Molded Part ◽

Molded Parts ◽

Fluid Channel ◽

Injection Molded

AbstractIn this study, PPS blended with as high as 50 wt% carbon fiber were injection molded. Effects of molding conditions as well as the melt flow condition parallel and perpendicular to fluid channel on the surface conductivity was investigated. It was found that mold temperature affects the surface conductivity of molded parts significantly. Using a variable mold temperature control system based on electromagnetic induction heating, the conductivity of the molded part increase by about 152% when the peak mold temperature increases from 120 °C to 210 °C. The channel layout also helps the fiber to orient more randomly leading to an increase in the conductivity. The channel design parallel to melt flow increases the conductivity by 152% and when it is perpendicular to melt flow, the conductivity increases by 95%. Channel layout perpendicular to melt flow direction provides more influence on the fiber reorientation than that of the parallel design.

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