Low-temperature MOCVD of molybdenum sulfide on silicon and 100Cr6 steel substrates

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-637-Pr8-642
Author(s):  
F. Senocq ◽  
L. Bezombes ◽  
A. Gleizes ◽  
J. A. Garcia ◽  
R. J. Rodriguez
Keyword(s):  
Low Temperature ◽  
Molybdenum Sulfide ◽  
Steel Substrates

scholarly journals Reactive Pulsed Laser Deposition of Clustered-Type MoSx (x ~ 2, 3, and 4) Films and Their Solid Lubricant Properties at Low Temperature

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 653 ◽  
Author(s):  
V. Fominski ◽  
M. Demin ◽  
V. Nevolin ◽  
D. Fominski ◽  
R. Romanov ◽  
...  
Keyword(s):  
Low Temperature ◽  
Pulsed Laser Deposition ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Sliding Friction ◽  
Pulsed Laser ◽  
Molybdenum Sulfide ◽  
Laser Deposition ◽  
Thin Film Coatings ◽  
Mos2 Coating

We studied the tribological properties of amorphous molybdenum sulfide (MoSx) thin-film coatings during sliding friction in an oxidizing environment at a low temperature (−100 °C). To obtain films with different sulfur contents (x ~ 2, 3, and 4), we used reactive pulsed laser deposition, where laser ablation of the Mo target was performed in H2S at various pressures. The lowest coefficient of friction (0.08) was observed during tribo-testing of the MoS3 coating. This coating had good ductility and low wear; the wear of a steel counterbody was minimal. The MoS2 coating had the best wear resistance, due to the tribo-film adhering well to the coating in the wear track. Tribo-modification of the MoS2 coating, however, caused a higher coefficient of friction (0.16) and the most intensive wear of the counterbody. The MoS4 coating had inferior tribological properties. This study explored the mechanisms of possible tribo-chemical changes and structural rearrangements in MoSx coatings upon contact with a counterbody when exposed to oxygen and water. The properties of the tribo-film and the efficiency of its transfer onto the coating and/or the counterbody largely depended on local atomic packing of the nanoclusters that formed the structure of the amorphous MoSx films.

Aluminizing Coating Prepared on Oil Casing Steel N80 by Low-Temperature Pack Cementation

2011 ◽  
Vol 368-373 ◽  
pp. 2180-2184
Author(s):  
Yu Wang ◽  
Min Huang
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Aluminide Coating ◽  
Electrochemical Corrosion ◽  
Hardness Test ◽  
Element Distribution ◽  
Pack Cementation ◽  
Mechanical Attrition ◽  
Pre Treatment ◽  
Steel Substrates

Aluminizing has been verified to be an effective way to improve the corrosion resistance of steel due to the formation of continuous Al2O3layer, but traditional aluminizing processing carried out at high temperature can not be used to prepare aluminide layer on the surface of oil casing steel. In this paper, an aluminide coating was prepared on oil casing steel N80 by a low-temperature pack cementation only at 803 K for 2 hours by adding zinc in the pack powder and pre-treatment of N80 substrate by surface mechanical attrition. The phase compostion, microstructure, element distribution and properties of as-aluminized oil casing steel N80 were characterized by means of XRD, SEM, EDS, micro-hardness test and electrochemical corrosion measurements. The results indicate that aluminide coating mainly consists of FeAl3, Fe2Al5 and FeAl. The continuous aluminide coating with an average thickness around 50 μm could be successfully formed on the surface of oil casing steel N80 which shows a good coherence with as-packed substrate. After preparation of aluminide coating, oil casing steel N80 shows a higher microhardness in the range of aluminizing coating than that of the virgin material because of the formation of iron aluminide. The exception noted is that the proposed low-temperature aluminizing processing does not have any damaging impact on the mechanical properties of steel substrates. Moreover, it is concluded that oil casing steel N80 with aluminizing coating shows a better corrosion resistance than that of original N80 by analyzing of electrochemical test results.

scholarly journals Long-Term Testing of WC–Ni–Fe Coating as an Inert Anode in a Low-Temperature Electrolyte for Aluminum Production

2019 ◽  
Vol 26 (2) ◽  
pp. 179-184
Author(s):  
Chuhua LIU ◽  
Yudong WANG ◽  
Bin YANG ◽  
Yongnian DAI
Keyword(s):  
Low Temperature ◽  
Erosion Resistance ◽  
Inert Anode ◽  
Electrical Current ◽  
Substrate Material ◽  
Aluminum Production ◽  
Contamination Level ◽  
Deposited Metal ◽  
Steel Substrates

The behaviour of WC-Ni-Fe coating on 2Cr13 and X3CrNiMo18-12-3 stainless steel substrates was investigated in the context of their application as inert anode materials in a low-temperature (850 °C) electrolyte (50 wt.% AlF3-45 wt.% KF-5 wt.% Al2O3) by long-term testing around 50 h for aluminum production. The results show that the materials were corroded in a controlled manner and the extrapolated corrosion rates of WC–Ni–Fe/X3CrNiMo18-12-3 anode was 5.8 cm per year, which is acceptable from an industrial perspective. The total contamination level of anode constituents in the deposited metal was as low as 0.283 wt.%. These encouraging results seemed to be related in part to the X3CrNiMo18-12-3 substrate that allows only very slow penetration of oxygen atoms into the inner part. Post-electrolysis examination of the anodes indicates that the substrate material is one of the most important factors that determine the erosion resistance of coating inert anode. The results of electrolysis using 2Cr13 and X3CrNiMo18-12-3 substrates indicate that the electrical current is another important factor for the erosion resistance of inert anode coatings.

CORROSION RESISTANT CERAMIC COATING FOR X80 PIPELINE STEEL BY LOW-TEMPERATURE PACK ALUMINIZING AND OXIDATION TREATMENT

2013 ◽  
Vol 20 (06) ◽  
pp. 1350063
Author(s):  
HUANG MIN ◽  
FU QIAN-GANG ◽  
WANG YU ◽  
ZHONG WEN-WU
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Ceramic Coating ◽  
Pipeline Steel ◽  
Ceramic Coatings ◽  
X80 Pipeline Steel ◽  
Oxidation Treatment ◽  
Pack Aluminizing ◽  
Steel Substrates ◽  
Al Coating

In this paper, we discuss the formation of ceramic coatings by a combined processing of low-temperature pack aluminizing and oxidation treatment on the surface of X80 pipeline steel substrates in order to improve the corrosion resistance ability of X80 pipeline steel. First, Fe - Al coating consisting of FeAl 3 and Fe 2 Al 5 was prepared by a low-temperature pack aluminizing at 803 K which was fulfilled by adding zinc in the pack powder. Pre-treatment of X80 pipeline steel was carried out through surface mechanical attrition treatment (SMAT). Further oxidation treatment of as-aluminized sample was carried out in the CVD reactor at 833 K under oxygen containing atmosphere. After 1 h duration in these conditions, ceramic coating consisting of α- Al 2 O 3 was formed by in situ oxidation reaction of Fe - Al coating. Those coatings have been characterized by different techniques including X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscope (EDS), respectively. Ceramic coating shows a dense and uniform microstructure, and exhibits good coherences with X80 pipeline steel substrates. By electrochemical corrosion test, the self-corrosion current density of X80 pipeline steel with as-obtained ceramics coating in 3.5% NaCl solution shows an obvious decrease. The formation of α- Al 2 O 3 ceramic coating is considered as the main reason for the corrosion resistance improvement of X80 pipeline steel.

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

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