Single and Multielement Coatings in a Fluidized Bed Reactor

2016 ◽  
Vol 258 ◽  
pp. 379-382
Author(s):  
Konstantinos Anthymidis ◽  
Afroditi Trakali ◽  
Dimitrios N. Tsipas
Keyword(s):  
Fluidized Bed ◽  
Surface Engineering ◽  
Fluidized Bed Reactors ◽  
X Rays ◽  
Corrosion Properties ◽  
Corrosion Resistant ◽  
Wear And Corrosion ◽  
Boride Coatings ◽  
High Fatigue ◽  
Boron Silicide

Heat treatments of alloys in fluidized bed reactors have been carried out for more than twenty-five years. Recently this technology has been used for surface engineering applications in the deposition of hard and/or corrosion resistant layers e.g. aluminizing, chromizing, nitriding, carburizing, boronizing. The fluidized bed method is simple, efficient, environmentally friendly and capable of immediate adjusting the furnace atmosphere for specific requirements e.g. production of multielement coatings. The boride coatings on steel have an excellent combination of properties e.g. high fatigue strength and wear resistance. On the other hand silicide coatings are well known for their excellent corrosion resistance. Boron-siliconizing in fluidized beds is a promising method to improve both the wear and corrosion properties of steels. In the present paper fluidized bed technology (FBT) was used to deposit boride and boron-silicide coatings on steels. The coatings were examined by means of electron and optical microscopy and X-Rays diffraction, in terms of the coatings composition, morphology, thickness and phase formation. The coatings tribological properties were evaluated under dry wear.

Production and Characterization of Boride Coatings on Steels

2019 ◽  
Vol 827 ◽  
pp. 61-66
Author(s):  
Konstantinos Anthymidis ◽  
Afroditi Trakali ◽  
Dimitrios N. Tsipas
Keyword(s):  
Fluidized Bed ◽  
Surface Engineering ◽  
X Rays ◽  
Wear And Corrosion ◽  
Boride Coatings ◽  
Wear And Corrosion Resistance ◽  
Pin On Disk ◽  
Steel Substrates

Boride coatings on steels have an excellent combination of properties. They can significantly improve the hardness, the wear and corrosion resistance of steels. Boronizing of steels has been achieved using different methods such as pack cementation and paste boriding. On the other hand, fluidized bed technology has been successfully used in many surface engineering applications in the deposition of hard and / or corrosion resistant layers e.g. carburizing, aluminizing and chromizing. This method is simple, efficient and environmental friendly and is characterized by excellent heat and mass transfer, which results to improve quality of the as-produced coatings. As a result, fluidized bed technology can be considered as a useful alternative method for the production of boride coatings on steel substrates. In the present paper we used this method to deposit boride coatings on steels. The as-produced coatings were examined by means of optical microscopy, X-Rays diffraction, Vickers microhardness and pin on disk in terms of coatings thickness and morphology, phase formation and mechanical properties. It was found that they are characterized by good adherence and uniformity all over the substrate and showed improved tribological properties under dry wear conditions.

Effect of TiN Coating on Functional Properties of Implant Titanium Alloy

2009 ◽  
Vol 147-149 ◽  
pp. 782-787 ◽  
Author(s):  
Małgorzata Grądzka-Dahlke ◽  
Anna Bukrym ◽  
Emilia Choińska
Keyword(s):  
Functional Properties ◽  
Surface Engineering ◽  
Tin Coating ◽  
Corrosion Properties ◽  
Joint Friction ◽  
Test Conditions ◽  
Wear And Corrosion ◽  
Adverse Influence ◽  
Implant Alloys ◽  
Wear And Corrosion Resistance

Surface engineering is considered a very prospective method of improving functional properties of implant alloys. Many publications reported the excellent influence of TiN coating on wear resistance as well as corrosion properties of titanium alloys. However, some authors pointed the danger of delamination of thin coating during exploitation. The aim of presented work was research of effect of TiN coating obtained by the RF-PCVD method on tribological and corrosion properties of Ti6Al4V alloy. Investigations performed by the simulator of hip joint friction as well as corrosion tests carried out at various temperatures showed adverse influence of TiN coating on wear and corrosion resistance. Analysis of presented date demonstrate that results strongly depend on test conditions.

Siliconizing in a Fluidized Bed Reactor

2013 ◽  
Vol 592-593 ◽  
pp. 409-412
Author(s):  
Konstantinos Anthymidis ◽  
Kostas David ◽  
Afroditi Trakali ◽  
D.N. Tsipas
Keyword(s):  
Corrosion Resistance ◽  
Fluidized Bed ◽  
Surface Engineering ◽  
Steel Substrate ◽  
Fluidized Bed Reactor ◽  
Promising Method ◽  
Engineering Applications ◽  
Corrosion Resistant ◽  
Excellent Corrosion Resistance

Fluidized bed technology has been used for surface engineering applications in the deposition of hard and/or corrosion resistant layers e.g. aluminizing, chromizing, nitriding, carburizing, boronizing. In the present paper we used fluidized bed technology (FBT) to deposit silicide coatings on steels. The silicide coatings are well known for their excellent corrosion resistance. Siliconizing in fluidized bed is a promising method to improve the corrosion resistance of steel without altering its other properties. The asproduced silicide coatings are uniform all over the steel substrate, with good thickness, adequate adherence and consisted only from the phase FeSiC.

CARPENTER CTS-204P ALLOY (MICRO MELT 20-4)

Alloy Digest ◽  
2010 ◽  
Vol 59 (1) ◽  
Keyword(s):  
Wear Resistance ◽  
Volume Fraction ◽  
Cold Work ◽  
Heat Treating ◽  
Corrosion And Wear ◽  
Corrosion Resistant ◽  
Die Steel ◽  
Powder Metallurgy Process ◽  
Wear And Corrosion ◽  
Metallurgy Process

Abstract Carpenter CTS-204P (Micro Melt 20-4) alloy is a highly wear- and corrosion-resistant, air-hardening martensitic cold-work stainless die steel produced using Carpenter’s Micro-Melt powder metallurgy process. The excellent wear resistance of the alloy is provided by a significant volume fraction of hard vanadium-rich carbides, while the outstanding corrosion resistance of the alloy is obtained as a result of the chromium-rich matrix. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on corrosion and wear resistance as well as forming, heat treating, and machining. Filing Code: SS-1051. Producer or source: Carpenter Specialty Alloys.

Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

1989 ◽  
Vol 21 (4-5) ◽  
pp. 157-165 ◽  
Author(s):  
F. Ehlinger ◽  
J. M. Audic ◽  
G. M. Faup
Keyword(s):  
Fluidized Bed ◽  
Future Development ◽  
Protein Concentration ◽  
Specific Activity ◽  
Fluidized Bed Reactor ◽  
Fluidized Bed Reactors ◽  
Support Material ◽  
Biofilm Development ◽  
Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

Anaerobic/aerobic biodegradation of pentachlorophenol using GAC fluidized bed reactors: optimization of the empty bed contact time

1997 ◽  
Vol 36 (6-7) ◽  
pp. 107-115 ◽  
Author(s):  
Gregory J. Wilson ◽  
Amid P. Khodadoust ◽  
Makram T. Suidan ◽  
Richard C. Brenner
Keyword(s):  
Fluidized Bed ◽  
Oxygen Demand ◽  
Aerobic Biodegradation ◽  
Fluidized Bed Reactors ◽  
Reactor Performance ◽  
Reactor Operation ◽  
Significant Cost ◽  
Second Stage ◽  
Primary Substrate ◽  
Chlorinated Phenolic Compounds

An integrated reactor system has been developed to remediate pentachlorophenol (PCP) containing wastes using sequential anaerobic and aerobic biodegradation. Anaerobically, PCP was degraded to predominately equimolar concentrations (>99%) of monochlorophenol (MCP) in two GAC fluidized bed reactors at Empty Bed Contact Times (EBCTs) ranging from 18.6 to 1.15 hours. However, at lower EBCTs, MCP concentrations decreased to less than 10% of the influent PCP concentration suggesting mineralization. The optimal EBCT was determined to be 2.3 hours based on PCP conversion to MCPs and stable reactor operation. Decreasing the EBCT fourfold did not inhibit degradation of PCP and its intermediates, thus allowing removal of PCP at much lower detention time and resulting in a significant cost advantage. Analytical grade PCP was fed via syringe pumps into two fluidized bed reactors at influent concentrations of 100 mg/l and 200 mg/l, respectively. Acting as the primary substrate, ethanol was also fed into the reactors at concentrations of 697 and 1388 mg/l. Effluent PCP and chlorinated phenolic compounds were analyzed weekly to evaluate reactor performance. Biodegradation pathways were also identified. 3-chlorophenol (CP) was the predominant MCP and varied simultaneously with 3,5-dichlorophenol (DCP) concentrations. Likewise, 4-CP concentrations varied simultaneously with 3,4-DCP concentrations. A second stage aerobic GAC fluidized bed reactor was added after the anaerobic reactor to completely mineralize the remaining MCP and phenols. Data show no presence of phenol and MCP in the effluent or on the GAC. Overall, the chemical oxygen demand (COD) fed to the system was reduced from 75 g/d in the influent to less than 1.5 g/d in the effluent.

Functional protective coatings of nickel-based alloys

2019 ◽  
pp. 110-114
Author(s):  
D. A. Gerashchenkov ◽  
T. I. Bobkova ◽  
A. F. Vasiliev ◽  
P. A. Kuznetsov ◽  
E. A. Samodelkin ◽  
...  
Keyword(s):  
Environmental Influence ◽  
Protective Coatings ◽  
Cold Gas Dynamic Spraying ◽  
Functional Elements ◽  
Corrosion Resistant ◽  
Gas Dynamic ◽  
Precision Alloy ◽  
Wear And Corrosion ◽  
High Level ◽  
Corrosion Resistant Coatings

A composition of a precision alloy based on the Ni–Cr–Mo system for wear and corrosion-resistant coatings by supersonic cold gas dynamic spraying has been developed. The optimum coatings composition provides high level of operational properties; its application is very promising for protection of structural and functional elements of marine equipment from aggressive environmental influence.

Aromatic Transformation in Fluidized Bed Reactors

2008 ◽  
Vol 73 (8-9) ◽  
pp. 1061-1088
Author(s):  
Sule Rabiu ◽  
Sulaiman Al-Khattaf
Keyword(s):  
Fluidized Bed ◽  
The Other ◽  
Fluidized Bed Reactors ◽  
Y Zeolite ◽  
Y Zeolites ◽  
Toluene Disproportionation ◽  
Xylene Isomerization ◽  
Toluene Methylation ◽  
Toluene Conversion ◽  
Medium Acidity

In this work three important aromatic transformations, namely: toluene disproportionation, toluene methylation and m-xylene isomerization, were investigated in a riser simulator which closely mimics the operation of commercial fluidized bed reactors. The transformations were studied over a ZSM-5 based catalyst with medium acidity of 0.23 mmol/g and a series of Y zeolites of acidities between 0.55 and 0.03 mmol/g. For pure toluene feed, it was observed that conversion over the ZSM-5 based catalyst and the weakly acidic Y zeolite (USY-1) was very low. However, with the highly acidic Y zeolite (H-Y), significant toluene conversion was observed with paring reaction more prominent than disproportionation. On the other hand, when toluene was alkylated with methanol, higher toluene conversions were achieved over both the ZSM-5 based and the weakly acidic USY-1 catalysts as compared to when pure toluene feed was used. In addition, p-xylene/o-xylene (P/O) ratios higher than the equilibrium values were obtained in the reaction product over both catalysts. Finally, for m-xylene isomerization it was found that m-xylene conversion increased initially as the acidity of the catalyst increased up to 0.1 mmol/g beyond which any further increase in acidity resulted in a slight decrease in the m-xylene conversion.

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