Effects of Mg Additions on Surface Morphology and Corrosion Resistance of Hot-Dipped Zn Coatings

2008 ◽  
Vol 273-276 ◽  
pp. 300-305 ◽  
Author(s):  
Lucia Suarez ◽  
Frans Leysen ◽  
C. Masquelier ◽  
D. Warichet ◽  
Yvan Houbaert
Keyword(s):  
Corrosion Resistance ◽  
Construction Material ◽  
Coating Properties ◽  
Surface Layers ◽  
Corrosion Tests ◽  
X Ray ◽  
Cyclic Corrosion ◽  
Wide Range ◽  
Excellent Method

Steel is still the main construction material for automobiles, general equipment and industrial machinery. Hot dipping has been proven to be an excellent method of corrosion protection of steels for a wide range of applications worldwide. Coatings of Zn-Al alloys on steel sheet have high corrosion resistance due to the corrosion prevention ability from Zn and the passivation of Al Bath composition, immersion velocity/time and substrate composition are the hot dipping parameters that more influence on the thickness and corrosion resistance of the deposited coating. In order to study their influence small amounts of magnesium were added. Experiments were performed in a hot dipping simulator using different substrates, bath compositions and hot dipping parameters. Surface layers were characterised by: Scanning Electron Microscopy (SEM) and Energy dispersive X-Ray spectroscopy (EDX or EDS). Cyclic corrosion tests were performed in order to observe the corrosion resistance for different Zn-Al-Mg coatings. Results show that the microstructure and composition of the substrate strongly affect the desired coating properties. Nevertheless, the influence of the magnesium on coating thickness is relevant, increasing when added in small quantities in a molten bath of Zn-5wt %Al. The quality and microstructure of the coating is affected by the amount of Mg in the bath. Cyclic corrosion tests results show that the quality of the coating is affected by the amount of Mg in the bath.

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.

scholarly journals A microstructural and corrosion resistance study of (Zr, Si, Ti)N-Ni coatings produced through co-sputtering

DYNA ◽  
2018 ◽  
Vol 85 (207) ◽  
pp. 192-197 ◽  
Author(s):  
Estrella Natali Borja-Goyeneche ◽  
Jhon Jairo Olaya-Florez
Keyword(s):  
Corrosion Resistance ◽  
Nickel Content ◽  
Corrosion Current ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Current Densities ◽  
Fcc Phase

This work researches the influence of the nickel content on the structural and anticorrosive properties of ZrSiTiN films deposited by means of reactive co-sputtering on alloys of Ti6Al4V. The morphology and structure were analyzed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the chemical composition was identified via X-ray scattering spectroscopy (EDS). The corrosion resistance was studied using potentiodynamic polarization (PP) tests employing a 3.5% by weight NaCl solution. In the films, an increase of Ni up to 6.97 at% was observed, while in XRD the FCC phase of (Zr, Ti) N was identified, with a mixed orientation in planes (111) and (200), which tended to diminish with the increase of Ni. Finally, with the addition of Ni, the corrosion current densities were reduced from 5.56 𝑥 10−8 to 2.64 𝑥 10−9 𝐴/𝑐m2. The improvement in the corrosion resistance is due to the effect of the Ni on the microstructure of the system (Zr, Ti) N, which can improve the quality of the passive film and prevent crystalline defects and corrosion zones.

Effect of Bismuth on the Microstructure and Corrosion Resistance of Galvanized Coating

2011 ◽  
Vol 391-392 ◽  
pp. 1183-1188 ◽  
Author(s):  
Jian Hua Wang ◽  
Xing Ming Wang ◽  
Chun Mei Liu ◽  
Xu Ping Su ◽  
Chang Jun Wu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Electrochemical Corrosion ◽  
Energy Dispersive ◽  
Phase Layer ◽  
Corrosion Tests ◽  
X Ray ◽  
Galvanized Coating ◽  
Scanning Electron

The microstructure of the galvanized coating was investigated using scanning electron microscope equipped with energy dispersive X-ray spectroscope. The immersing and electrochemical corrosion tests were carried out to study the corrosion resistance of the galvanized coating. The addition of Bi in Zn-bath affects remarkably the morphology of the galvanized coating. The thickness of δ + ζ phase layer in the coating reaches the maximum when the content of Bi in Zn-bath is 0.5 wt.%. The corrosion resistance of the galvanized coating declines with the increase of the content of Bi.

scholarly journals Portable X-ray fluorescence (pXRF) calibration for analysis of nutrient concentrations and trace element contaminants in fertilisers

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262460
Author(s):  
Gifty E. Acquah ◽  
Javier Hernandez-Allica ◽  
Cathy L. Thomas ◽  
Sarah J. Dunham ◽  
Erick K. Towett ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Nutrient Concentrations ◽  
Good Prediction ◽  
X Ray ◽  
Accuracy And Precision ◽  
Wide Range ◽  
High Throughput Detection ◽  
Characterisation Methods

With the increasing popularity of local blending of fertilisers, the fertiliser industry faces issues regarding quality control and fertiliser adulteration. Another problem is the contamination of fertilisers with trace elements that have been shown to subsequently accumulate in the soil and be taken up by plants, posing a danger to the environment and human health. Conventional characterisation methods necessary to ensure the quality of fertilisers and to comply with local regulations are costly, time consuming and sometimes not even accessible. Alternatively, using a wide range of unamended and intentionally amended fertilisers this study developed empirical calibrations for a portable handheld X-ray fluorescence (pXRF) spectrometer, determined the reliability for estimating the macro and micro nutrients and evaluated the use of the pXRF for the high-throughput detection of trace element contaminants in fertilisers. The models developed using pXRF for Mg, P, S, K, Ca, Mn, Fe, Zn and Mo had R2 values greater or equal to 0.97. These models also performed well on validation, with R2 values greater or equal to 0.97 (except for Fe, R2val = 0.55) and slope values ranging from 0.81 to 1.44. A second set of models were developed with a focus on trace elements in amended fertilisers. The R2 values of calibration for Co, Ni, As, Se, Cd and Pb were greater than or equal to 0.80. At concentrations up to 1000 mg kg-1, good validation statistics were also obtained; R2 values ranged from 0.97–0.99, except in one instance. The regression coefficients of the validation also had good prediction in the range of 0–100 mg kg-1 (R2 values were from 0.78–0.99), but not as well at lower concentrations up to 20 mg kg-1 (R2 values ranged from 0.10–0.99), especially for Cd. This study has demonstrated that pXRF can measure several major (P, Ca) and micro (Mn, Fe, Cu) nutrients, as well as trace elements and potential contaminants (Cr, Ni, As) in fertilisers with high accuracy and precision. The results obtained in this study is good, especially considering that loose powders were scanned for a maximum of 90 seconds without the use of a vacuum pump.

IMPROVING THE CORROSION RESISTANCE OF RЕM–Fe–B MAGNETS

2021 ◽  
pp. 97-107
Author(s):  
D.S. Gorlov ◽  
◽  
I.V. Cherednichenko ◽  
R.A. Valeev ◽  
D.V. Chesnokov ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Plasma Coating ◽  
Comparative Assessment ◽  
Vacuum Arc ◽  
Corrosion Tests ◽  
Ion Plasma ◽  
Cyclic Corrosion

The article presents the results of work on improving the corrosion resistance of magnets of the REM–Fe–B system manufactured in China, by applying an ion-plasma coating of the SDP-1T + VSDP-13 system on an industrial vacuum-arc installation MAP-3. A comparative assessment of the tread protection of the vacuum-arc coating of the SP-1T + VSP-13 system was carried out with an already applied Ni–Cu–Ni coating under conditions of accelerated cyclic corrosion tests at a temperature of 300 °C. The coating of the SDP-1T + VSDP-13 system, applied in the FSUE «VIAM», creates a much more resistant protection of the magnets of the REM–Fe–B system from corrosion compared to the electroplating of the Ni–Cu–Ni system, manufactured in China.

Line Profile Analysis (LPA) Methods: Systematic Ranking of the Quality of their Basic Assumptions

2004 ◽  
Vol 443-444 ◽  
pp. 127-130
Author(s):  
Arnold C. Vermeulen ◽  
Rob Delhez
Keyword(s):  
Line Profile ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Line Profiles ◽  
Qualitative Comparison ◽  
New Developments ◽  
X Ray ◽  
Basic Assumptions ◽  
Wide Range

All methods of analyzing the broadening of XRD line profiles have to take into account two basic effects: broadening by the instrument - including the X-ray spectrum - and the characteristics of broadening by size effects and by lattice defects - including their interaction. These effects are handled in practice by a wide range of auxiliary assumptions. In this paper these assumptions and their quality with respect to "appropriateness of purpose" are listed and compared. By systematic ranking of these assumptions in accordance with their quality, a 2-dimensional map can be constructed that visualizes the differences in the quality of the assumptions. This 2-dimensional map brings a new viewpoint to the various methods for line profile analysis, because it enables a qualitative comparison of the assumptions of existing methods and new developments.

scholarly journals MACHINERY QUALITY SUPPORT BASED ON IMPRUVEMENT OF METHODS AND MEANS FOR ESTIMATE OF TRIBO-TECHNICAL PARAMETERS OF MACHINERY FUNCTIONAL UNITS

2020 ◽  
Vol 2020 (2) ◽  
pp. 19-27
Author(s):  
Galina Pilyushina ◽  
Evgeniy Pamfilov ◽  
Pavel Pyrikov ◽  
Vladimir Kapustin
Keyword(s):  
Production Method ◽  
Parameter Estimate ◽  
Surface Layers ◽  
Essential Condition ◽  
Technical Parameters ◽  
Friction Units ◽  
Wide Range ◽  
Properties Of Materials ◽  
Quality Of Products

The choice of possible ways for machinery quality increase must be based on the investigation results of wear regularities and also on the experimental data obtained in the course of laboratory nature and production method use with the aid corresponding equipment use. The purpose of the work is updating methods and means for the estimate of tribo-technical unit operation parameters. Tribo-technical tests must reproduce a wide range of events taking place at different interactions of machinery surface layers with wear environment under different conditions of operation. The more trustworthy the estimated figures in the course of the experiments carried out, the larger potentialities for quality increase of products manufactured. To obtain reliable data the essential condition is the reproduction of conditions taking place in the course of the operation of the samples under investigation. The modeling of parts wear processes on the plants presented and reproducing wear mechanisms under conditions of operation allows revealing the peculiarities of a contact interaction, wear regularities and defining the efficient ways for parts life increase ensuring proper quality of products manufactured. The methods and equipment developed for tribo-technical parameter estimate allow characterizing more precisely the values of physical stress-strain properties of materials under investigation and sure forecasting the working capacity of friction units under specified conditions of operation.

Study on Impacts of the Power Spinning Process on the Properties of Hastelloy C-276

2013 ◽  
Vol 442 ◽  
pp. 3-8
Author(s):  
Zong Zhang
Keyword(s):  
Corrosion Resistance ◽  
Weld Zone ◽  
Cylindrical Part ◽  
Corrosion Tests ◽  
X Ray ◽  
Power Spinning ◽  
Post Annealing ◽  
Spinning Process

After a Hastelloy C-276 cylindrical part goes through the power spinning process, X-ray detection, and tensile and corrosion tests, the directivity of grains in the cylindrical part is enhanced, and the weld zone strength and post-annealing corrosion resistance greatly promoted.

Correlation of Surface Characteristics and Thermal Conductivity of High Silica Glass Fibre Materials

2008 ◽  
Vol 39-40 ◽  
pp. 193-196 ◽  
Author(s):  
Janina Setina ◽  
V. Akishins ◽  
L. Petersone
Keyword(s):  
Thermal Conductivity ◽  
Surface Roughness ◽  
Glass Fibre ◽  
Silica Glass ◽  
Surface Characteristics ◽  
Woven Fabrics ◽  
X Ray ◽  
Wide Range ◽  
High Silica

The new generation of high silica materials with high thermal resistance was created by leaching of chopped glass fibre. These materials with low thermal conductivity are inert to the majority of chemical reagents, resistant to organic and mineral acids, weak alkali, water and highpressure steam. High silica chopped strand mats are non-woven fabrics designed for using in a wide range of insulation and protection applications at temperature till 11000C. The technology and quality of leaching process of initial Si-Al-Na glass widely depends on quality of fibre surface characteristics, i.e., roughness of surface of glass filaments. The surface roughness of the fibre before leaching is a function of chemical durability, therefore it depend on content of Al2O3. The thermal conductivity (within 20…10000C) of chopped strand mats directly depends on the surface roughness. The morphology and compositional profiles of surface of glass fibre before and after leaching were investigated using AFM, SEM, X-ray microanalysis and X-ray powder diffractometer. The different defects for fibre with content of Al2O3 <2.5% and high roughness namely cracking and crystalline deposits of Na2SO4 on top and into pores of fiber after leaching have been identified. The presence of sodium ions on surface of fibre decreases the heat insulation properties of mats. The structure of glass filaments surface was investigated in order to clarify the influence of surface characteristics on thermal conductivity of high silica glass fibre non-woven fabrics.

Sign in / Sign up

Export Citation Format

Share Document