Microstructure and Properties of TiC-CrNiMo SHS Spray Powder and Thermally Sprayed Coating

2000 ◽  
Author(s):  
M. Väisänen ◽  
P. Vuoristo ◽  
T. Mäntylä ◽  
V. Maunu ◽  
P. Lintunen ◽  
...  
Keyword(s):  
Particle Size ◽  
Corrosion Behaviour ◽  
Metallic Matrix ◽  
Electrochemical Corrosion ◽  
Wear Test ◽  
Spherical Shape ◽  
Open Circuit ◽  
Hvof Spraying ◽  
Particle Size Range ◽  
Abrasion Wear

Abstract Titanium carbide cermet spray powder was produced by the SHS process (Self-propagating High-temperature Synthesis) using elemental Ti, C, Mo and prealloyed CrNiMo powders as starting materials. The powder was characterised (particle size distribution, phase structure, morphology) and the internal structure of each cermet particle was found out to be dense consisting of fine distribution of carbides embedded in a metallic matrix. The particle size range suitable for thermal spraying was obtained by sieving and air classifying. The coatings were prepared by HVOF spraying (DJH2600 and DJH2700). The dry abrasion wear resistance was evaluated by the rubber wheel abrasion wear test and electrochemical corrosion behaviour by open circuit potential measurements. According to the XRD analysis the amount of retained carbides in the coatings is high and the carbide phase has a spherical shape also in the coatings. The microstructure of coatings obtained is dense and the coatings possess good properties in wear and corrosion tests. WC-Co-Cr and Cr3C2-NiCr powders were used for comparison.

Electrochemical Corrosion Behaviour of ZrN Film in Various Corrosive Fluid

2015 ◽  
Vol 3 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Vishnu R. ◽  
Jiten Das ◽  
S. B. Arya ◽  
Manish Roy
Keyword(s):  
Sea Water ◽  
Corrosion Behaviour ◽  
Water Solution ◽  
Electrochemical Corrosion ◽  
High Hardness ◽  
Corrosion Current ◽  
Plain Carbon Steel ◽  
Open Circuit ◽  
Protective Film ◽  
Hank’S Solution

Recently, ZrN has been attracting interest for its excellent corrosion resistance, biocompatibility, high hardness, good lubricity and ductility. Although tribological study of ZrN coating has been carried out extensively, investigation related to corrosion of ZrN film is limited. In view of this and in view of possible applications of ZrN film in several engineering components, the present investigation has been undertaken to evaluate the corrosion response of ZrN film in seawater solution, Hank's solution, 0.5M H2SO4solution and 0.5M HCl solutions. Towards that purpose, potentiostatic, open circuit potential and potentiodynamic study of ZrN film deposited on plain carbon steel has been carried out in all these solutions. Results indicate that stable protective film is formed on the surface of ZrN coating in all these solution except 0.5M H2SO4 solution. The formation of protective film on ZrN coating is fastest in sea water solution and it is slowest in the Cl¯ ions containing media, 0.5 M HCl. The corrosion current is highest for 0.5M H2SO4 acid solution and least for Hank's solution.

The Effect of the Molecular Structure of Cyanine Dye on the Corrosion of Low-Carbon Steel in Hydrochloric Acid Solution

1994 ◽  
Vol 59 (3) ◽  
pp. 539-548 ◽  
Author(s):  
Mohamed Th. Makhlouf
Keyword(s):  
Carbon Steel ◽  
Corrosion Behaviour ◽  
Low Carbon Steel ◽  
Electrochemical Corrosion ◽  
Cyanine Dyes ◽  
Open Circuit ◽  
Ethyl Iodide ◽  
Cyanine Dye ◽  
Low Carbon ◽  
Steel Electrode

The effect of two different cyanine dyes 2-(2-hydroxystyryl)quinolinium-1-ethyl iodide (I) and 4-(2-hydroxystyryl)quinolinium-1-ethyl iodide (II) on the electrochemical corrosion behaviour of low-carbon steel (0.05% C, 0.04% Si, 0.023% S, 0.004% Cu) in HCl solution has been studied. Weight loss measurements, galvanostatic polarization curves, open-circuit potential variation of steel electrode with time and the cathodic protective current values show that the investigated cyanine dyes have an anticorrosive character. The inhibition effect depends mainly on the structure of the studied dye molecules, and is more pronounced in case of pretreated carbon steel with the dye solution before immersion in the corrosion medium than that obtained by addition of the dye to the corrosive medium.

scholarly journals Electrochemical Investigations of Steels in Seawater Sea Sand Concrete Environments

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5713
Author(s):  
Xiang Yu ◽  
Saad Al-Saadi ◽  
Xiao-Ling Zhao ◽  
R. K. Singh Raman
Keyword(s):  
Corrosion Resistance ◽  
Stainless Steels ◽  
Detrimental Effect ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Electrochemical Corrosion ◽  
Chloride Content ◽  
Open Circuit ◽  
Portland Cement Concrete ◽  
Sea Sand

Seawater and sea sand concrete (SWSSC) is an environmentally friendly alternative to ordinary Portland cement concrete for civil construction. However, the detrimental effect of high chloride content of SWSSC on the corrosion resistance of steel reinforcement is a concern. This study undertook the electrochemical corrosion behaviour and surface characterizations of a mild steel and two stainless steels (AISI type 304 and 316) in various simulated concrete environments, including the alkaline + chloride environment (i.e., SWSSC). Open circuit potential (OCP), potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) were employed. Though chloride is detrimental to the corrosion resistance of mild steels, a simultaneous presence of high alkalinity in SWSSC negate the detrimental effect of chloride. In the case of stainless steels, a high level of alkalinity is found to be detrimental, whereas chloride seems to have less detrimental effect on their corrosion resistance.

Electrochemical Corrosion Behaviour of Mg-(Ca,Mn) Sacrificial Anodes

2013 ◽  
Vol 795 ◽  
pp. 530-534
Author(s):  
Shaiful Rizam Shamsudin ◽  
Azmi Rahmat ◽  
Mahdi Che Isa ◽  
Mohd Nazree Derman ◽  
Abdul Razak Daud
Keyword(s):  
Corrosion Rate ◽  
High Performance ◽  
Corrosion Behaviour ◽  
Electrochemical Corrosion ◽  
Inert Atmosphere ◽  
Passive Layer ◽  
Open Circuit ◽  
Standard Samples ◽  
Casting Technique ◽  
Small Content

The aim of the study is to identify the effect of Ca in Mg-Mn alloy on electrochemical corrosion behavior for the development of high performance sacrificial anode. Mg alloys were fabricated by casting technique under an inert atmosphere. 0.35 ~ 1.11 wt.% of Ca were added as alloying element. The finding shows that the addition of small Ca in Mg-Mn anodes was found not significantly affecting the corrosion rate. However, small content of Ca was as much as necessary improving electronegativity of open circuit potential and modifying anodic polarization in promoting the instabilities of surface passive layer hence results in the further dissolution process between ion and alloy species underneath. No passivation occurs on the standard samples. Pitting profile only occur on Mg-Mn anode that has lower Ca content (0.35 wt. %). An XRD result shows no present of Mg2Ca phase on the as-cast anode containing 1.11 wt. % Ca. As a conclusion, the influence of small content of Ca was profoundly modifying electrochemically behaviour of Mg containing Mn anodes except corrosion rate.

Lead Hardening by Oxide Dispersion

2006 ◽  
Vol 514-516 ◽  
pp. 718-722
Author(s):  
F. Potecasu ◽  
O. Potecasu ◽  
Francisco Manuel Braz Fernandes ◽  
Viorica Muşat
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Powder Particle ◽  
Corrosion Behaviour ◽  
Metallic Matrix ◽  
Mechanical Resistance ◽  
Powder Particle Size ◽  
Oxide Dispersion ◽  
Air Jet ◽  
Lead Powder

Lead hardened through oxide scattering is investigated as raw materials for the fabrication of the support gratings of lead accumulators in order to increase their life service. For the preparation of lead powder hardened through oxide scattering we used air jet pulverisation, a technique specific to powder metallurgy. Two research approaches are presented in the paper: one in which the oxide was introduced through oxidised lead powder, and the other in which additional lead oxide was introduced. Oxide dispersion into metallic matrix was achieved by pronounced deformation through extrusion of the powder. During extrusion, the particles are compelled to pass through the mould calibration zone and consequently they are considerably deformed. As an effect of this deformation, the particles of fragile oxide which cover the lead powder particles are crashed and carried away to the material flowing through the matrix longitudinally on the extruded semiproduct. The content of oxide introduced in matrix by the oxidised lead powder depends on the powder particle size. This paper presents the effect of the powder particle size and oxide phase dispersion in the metallic matrix on the mechanical, chemical and electrical properties of the extruded semi-products. The semi-products made from lead powder belonging to the grain size class of < 40 µm and oxide particles allowance have the highest mechanical resistance and the best corrosion behaviour. Using controlled oxidised lead powder better extruded semi-products are obtained in terms of mechanical resistance, corrosion behaviour and electrical conductivity as compared with lead and Pb-Sb alloy. A higher electrical conductivity represents an important advantage especially for the starting accumulators where the voltage fall should be as low as possible.

381. Sampling Efficiencies of Three Personal Aerosol Samplers within and Beyond the Inhalable Particle Size Range

2001 ◽  
Author(s):  
V. Aizenberg ◽  
P. Baron ◽  
K. Choe ◽  
S. Grinshpun ◽  
K. Willeke
Keyword(s):  
Particle Size ◽  
Size Range ◽  
Particle Size Range

Application of Plakett-Burman Screening Design in Optimization of Process Parameters for Formulation of Canaglifozin Nanosuspension

2020 ◽  
Vol 13 (6) ◽  
pp. 5208-5216
Author(s):  
Nisha Patel ◽  
Hitesh A Patel
Keyword(s):  
Particle Size ◽  
Particle Diameter ◽  
Spherical Shape ◽  
Water Soluble ◽  
Pareto Chart ◽  
Independent Variables ◽  
Mean Particle Size ◽  
Screening Design ◽  
Stirring Time ◽  
Response Variables

In this study, we sought to improve the dissolution characteristics of a poorly water-soluble BCS class IV drug canaglifozin, by preparing nanosuspension using media milling method. A Plackett–Burman screening design was employed to screen the significant formulation and process variables. A total of 12 experiment were generated by design expert trial version 12 for screening 5 independent variables namely the amount of stabilizer in mg (X1), stirring time in hr (X2), amt of Zirconium oxide beads in gm (X3), amount of drug in mg (X4) and stirring speed in rpm (X5) while mean particle size in nm (Y1) and drug release in 10 min. were selected as the response variables. All the regression models yielded a good fit with high determination coefficient and F value. The Pareto chart depicted that all the independent variables except the amount of canaglifozin had a significant effect (p<0.001) on the response variables. The mathematical model for mean particle size generated from the regression analysis was given by mean particle size = +636.48889 -1.28267 amt of stabilizer(X1) -4.20417 stirring time (X2) -7.58333 amt of ZrO2 beads(X3) -0.105556 amt of drug(X4) -0.245167 stirring speed(X5) (R2=0.9484, F ratio=22.07, p<0.001). Prepared canaglifozin nanosuspension exemplified a significant improvement (p<0.05) in the release as compared to pure canaglifozin and marketed tablet with the optimum formulation releasing almost 80% drug within first 10min. Optimized nanosuspension showed spherical shape with surface oriented stabilizer molecules and a mean particle diameter of 120.5 nm. There was no change in crystalline nature after formulation and it was found to be chemically stable with high drug content.

Sign in / Sign up

Export Citation Format

Share Document