scholarly journals A grinding-burnishing approach to enhancing surface integrity, tribological and corrosion behaviour of laser-cladded AISI 431 alloys

2021 ◽  
pp. 1-15
Author(s):  
Mohammad Uddin ◽  
Remi Santifoller ◽  
Colin Hall ◽  
Thomas Schlaefer
Keyword(s):  
Corrosion Resistance ◽  
Surface Integrity ◽  
Performance Enhancement ◽  
Corrosion Behaviour ◽  
Impact Resistance ◽  
Corrosion Current ◽  
Surface Alteration ◽  
Modification Technique ◽  
And Performance ◽  
The Impact

Abstract This paper presents the influence of the grinding-burnishing on surface integrity and corrosion performance of the laser-cladded AISI 431 alloys. As-cladded specimens were first ground followed by plasticity ball burnishing. To evaluate surface alteration and performance enhancement, six major properties were measured and analysed in terms of surface roughness, porosity, microhardness, wear, and impact and corrosion resistance. Results showed that grinding-burnishing significantly improved the surface finish by lowering Ra and Rz by up to 29% and 41%, respectively, compared to grinding, while surface porosity was found to decrease by 18%. Maximum surface microhardness increased by 32% when grinding-burnishing, with a modified depth of up to 250 μm, while wear resistance increased by up to 38%. Because of hardness improvement, the grinding-burnishing increased the impact resistance by lowering the maximum indent depth by 29%. The corrosion resistance improved by increasing positive corrosion potential from − 0.31 V (grinding) to − 0.21 V (grinding-burnishing) and lowering corrosion current density from 1.18 × 10−3 A.cm−2 (for grinding) to 2.1 × 10−5 A.cm−2 (grinding-burnishing). Burnishing further induced grain modification in terms of grain deformation and flattening within microstructure, but no significant grain refinement was observed. XRD results however showed lattice deformation indicating potential compressive residual stress generated by burnishing. Overall, it is imperative to say that the combined grinding-burnishing can be a viable surface modification technique to extend functional service life of the laser-cladded components.

Role of Aluminium on the Microstructure and Corrosion Behaviour of Magnesium Prepared by Powder Metallurgy Method

2020 ◽  
Vol 17 (3) ◽  
pp. 8206-8213
Author(s):  
J. Alias
Keyword(s):  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Corrosion Behaviour ◽  
Corrosion Current ◽  
Optical Microscope ◽  
High Reactivity ◽  
Aluminium Content ◽  
Powder Metallurgy Method ◽  
X Ray Diffraction ◽  
Promising Development

Much research on magnesium (Mg) emphasises creating good corrosion resistance of magnesium, due to its high reactivity in most environments. In this study, powder metallurgy (PM) technique is used to produce Mg samples with a variation of aluminium (Al) composition. The effect of aluminium composition on the microstructure development, including the phase analysis was characterised by optical microscope (OM), scanning electron microscopy (SEM) and x-ray diffraction (XRD). The mechanical property of Mg sample was performed through Vickers microhardness. The results showed that the addition of aluminium in the synthesised Mg sample formed distribution of Al-rich phases of Mg17Al12, with 50 wt.% of aluminium content in the Mg sample exhibited larger fraction and distribution of Al-rich phases as compared to the 20 wt.% and 10 wt.% of aluminium content. The microhardness values were also increased at 20 wt.% and 50 wt.% of aluminium content, comparable to the standard microhardness value of the annealed Mg. A similar trend in corrosion resistance of the Mg immersed in 3.5 wt.% NaCl solution was observed. The corrosion behaviour was evaluated based on potentiodynamic polarisation behaviour. The corrosion current density, icorr, is observed to decrease with the increase of Al composition in the Mg sample, corresponding to the increase in corrosion resistance due to the formation of aluminium oxide layer on the Al-rich surface that acted as the corrosion barrier. Overall, the inclusion of aluminium in this study demonstrates the promising development of high corrosion resistant Mg alloys.

scholarly journals Glass-Forming Ability and Corrosion Resistance of Al88Y8−xFe4+x (x = 0, 1, 2 at.%) Alloys

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1581
Author(s):  
Rafał Babilas ◽  
Monika Spilka ◽  
Katarzyna Młynarek ◽  
Wojciech Łoński ◽  
Dariusz Łukowiec ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Analytical Techniques ◽  
Corrosion Current ◽  
Glass Forming Ability ◽  
Electrochemical Tests ◽  
Glass Forming ◽  
Transmission Electron ◽  
Composition And Structure ◽  
Amorphous Structures ◽  
The Impact

The effect of iron and yttrium additions on glass forming ability and corrosion resistance of Al88Y8-xFe4+x (x = 0, 1, 2 at.%) alloys in the form of ingots and melt-spun ribbons was investigated. The crystalline multiphase structure of ingots and amorphous-crystalline structure of ribbons were examined by a number of analytical techniques including X-ray diffraction, Mössbauer spectroscopy, and transmission electron microscopy. It was confirmed that the higher Fe additions contributed to formation of amorphous structures. The impact of chemical composition and structure of alloys on their corrosion resistance was characterized by electrochemical tests in 3.5% NaCl solution at 25 °C. The identification of the mechanism of chemical reactions taking place during polarization test along with the morphology and internal structure of the surface oxide films generated was performed. It was revealed that the best corrosion resistance was achieved for the Al88Y7Fe5 alloy in the form of ribbon, which exhibited the lowest corrosion current density (jcorr = 0.09 μA/cm2) and the highest polarization resistance (Rp = 96.7 kΩ∙cm2).

Effect of homogenization temperature and soaking time on the microstructure and corrosion properties of a twin roll casted AA3003

CORROSION ◽  
10.5006/3813 ◽  
2021 ◽  
Author(s):  
Donovan Verkens ◽  
Reynier Revilla ◽  
Mert Günyüz ◽  
Cemil Işıksaçan ◽  
Herman Terryn ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Heat Exchangers ◽  
Corrosion Behaviour ◽  
Life Time ◽  
Homogenization Temperature ◽  
Corrosion Properties ◽  
Cross Sectional ◽  
The Impact ◽  
Twin Roll

The AA3003 alloy is widely used as fin material in heat exchangers. The life time of these heat exchangers is mostly determined by their corrosion properties. Twin roll casting (TRC) of AA3003 material is known to often result in the formation of a macrosegregation area of alloying elements towards the centre plane of the casted strip (centre line segregation = CLS). Considering the potential exposure of cross-sectional areas of TRC material in the heat exchanger fin application, and the relatively high corrosion susceptibility of the CLS, the study of this region is of key importance to understand the microstructural effects on the resulting corrosion mechanisms and kinetics for these materials. Typically the alloys are homogenized to bring the microstructures closer to an equilibrium state, but the impact of this heat treatment on the corrosion properties is insufficiently studied. Therefore, this study investigates the effect of different homogenization procedures on the corrosion properties of the CLS and the interaction of the intermetallic particles with the surrounding aluminium matrix. This work shows that the pitting corrosion resistance is greatly dependent on the homogenization temperature, with better corrosion resistance obtained with higher temperature, especially near the CLS. This difference in corrosion behaviour is completely attributed to a difference in microstructure and not to an oxide layer effect. Furthermore, it is observed that not only temperature will have a large influence on the corrosion resistance, but duration of the heat treatment as well.

scholarly journals Preparation and Characterization of Low Infrared Emissive Aluminum/Waterborne Acrylic Coatings

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 35 ◽  
Author(s):  
Xiaoxing Yan ◽  
Lin Wang ◽  
Xingyu Qian
Keyword(s):  
Corrosion Resistance ◽  
Impact Resistance ◽  
Infrared Emissivity ◽  
Drying Time ◽  
Powder Concentration ◽  
Orthogonal Experiments ◽  
Adhesion Level ◽  
Small Change ◽  
Silica Slurry ◽  
The Impact

An aluminum/waterborne acrylic coating was developed by orthogonal experiments, and the gloss, emissivity, chromatic distortion, hardness, adhesion, impact resistance, and corrosion resistance of the coatings were examined. The results showed that the effect of drying time on the infrared emissivity of coatings was more significant than that of the Al powder concentration and nano-silica slurry. When the drying time was prolonged from 0.5 to 6.0 min, the gloss of the coating decreased slowly and the gloss remained low. The infrared emissivity first decreased and then increased. The infrared emissivity of coatings dried for 2.0 min was better. The L’ value gradually decreased and showed a small change of range. With the increasing of the drying time, the hardness of the coating gradually decreased and was the highest at 0.5–2.0 min. The drying time had no effect on the adhesion level. The impact resistance of the coating was better during the drying period of 1.0–3.0 min. The corrosion resistance of the coating was better at 2.0 min. When the drying time was 2.0 min, the waterborne coating showed the better comprehensive performance. This study provides new prospects in using low infrared emissive coatings for infrared stealth and compatibility with visible light.

scholarly journals Athletic performance, training characteristics, and orthopedic indications in junior tennis Davis Cup players

2016 ◽  
Vol 12 (1) ◽  
pp. 119-129 ◽  
Author(s):  
Janina Fett ◽  
Alexander Ulbricht ◽  
Thimo Wiewelhove ◽  
Alexander Ferrauti
Keyword(s):  
Performance Enhancement ◽  
Musculoskeletal Symptoms ◽  
Training Volume ◽  
Performance Training ◽  
Orthopedic Injury ◽  
Two Samples ◽  
High Prevalence ◽  
Junior Tennis ◽  
And Performance ◽  
The Impact

Our study aimed to examine athletics, training characteristics, and prevalence of musculoskeletal symptoms of male junior tennis Davis Cup players (DC) in comparison with their regional counterparts, as well as to evaluate the impact of age and performance level on training characteristics. Twelve junior DC (male) and two samples of regional squad players (RS1 n = 60 males, n = 47 females; RS2 n = 59 males) participated in a physical testing, an interview for data evaluation on training characteristics, and a questionnaire survey of orthopedic injury frequency. Results indicate higher physical performance levels (effect size (ES) 0.75–1.26) and training volumes in DC (ES 1.23–1.66). In DC, significant relationships were found between total training volume and tennis ranking ( r = −0.78), age and physical training volume ( r = 0.82), and age and total training volume ( r = 0.62). Injury frequencies showed moderate to high prevalence with no differences ( p > 0.05) between DC and RS. Given the demands of elite tennis and the important role of service in the modern game, more efforts are necessary to develop training prescription for both performance enhancement and prevention strategies.

The Effect of Hydrogen on Pitting Corrosion of Superaustenitic and Austenitic-Ferritic Stainless Steels

2012 ◽  
Vol 326-328 ◽  
pp. 620-625 ◽  
Author(s):  
Joanna Michalska
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Stainless Steels ◽  
Corrosion Current Density ◽  
Corrosion Behaviour ◽  
Corrosion Current ◽  
Passive Films ◽  
Cyclic Polarization ◽  
Film Stability ◽  
Ferritic Stainless Steels

Hydrogen entering into steel affects its electrochemical properties and may enhance the susceptibility to environmental degradation. The present work has been aimed at further clarifying the effect of hydrogenation on the corrosion behaviour and passivity of highly-alloyed stainless steels. The results were discussed by taking into account hydrogen charged samples and without hydrogen. The corrosion resistance to pitting was qualified with the cyclic polarization curves. The conclusion is that hydrogen may deteriorated the passive film stability and corrosion resistance to pitting of highly-alloyed stainless steel. Furthermore, the presence of hydrogen in passive films increases corrosion current density, decreasing the potential of the film breakdown and repassivation potential. It was also found that the degree of susceptibility to hydrogen-enhanced pitting corrosion was dependent on the type of steel.

scholarly journals Effect of Black Paste on the Property of Fluorine Resin/Aluminum Infrared Coating

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 597 ◽  
Author(s):  
Yan
Keyword(s):  
Corrosion Resistance ◽  
Impact Resistance ◽  
Engineering Application ◽  
Color Difference ◽  
Infrared Emissivity ◽  
Coating Surface ◽  
Anticorrosive Coatings ◽  
Paste Content ◽  
The Impact

A fluorine resin/aluminum infrared coating was prepared with aluminum using black paste as filler and fluorine resin as binder. The effect of the black paste content on the performance of gloss, color difference, infrared emissivity, hardness, adhesion, impact resistance, roughness, optical testing, and corrosion resistance of the fluorine resin/aluminum infrared coating were examined. When the content of black paste was increased from 1.0% to 9.0%, the gloss of the coating surface decreased; the ΔE* value of the coating decreased; the infrared emissivity of the coating surface increased gradually; the hardness of the coating was 6H; the adhesion grade of the coating was 0; the infrared absorption peak increased gradually. When the content of black paste was 0%–3.0%, the impact resistance was more than 50 kg∙cm, and the impact resistance was higher. When the content of black paste was 0%–5.0%, the surface roughness of the coating was relatively low. When the content of black paste was 1.0%, the corrosion resistance of the coating was the best. The results showed that when the content of black paste was 1.0%, the performance of the whole fluorine resin coating was the best. Through the preparation and characterization of fluorine resin infrared low-emissivity coatings, the possibility of applying fluorine resin to infrared low-emissivity anticorrosive coatings was discussed, which laid a foundation for the subsequent engineering application of coatings.

scholarly journals AN EXPLORATION OF THE IMPACT OF HOTEL FACILITIES ON EMPLOYEE MOTIVATION AND PERFORMANCE: AN INDONESIA CASE STUDY

2021 ◽  
Vol 1 (1) ◽  
pp. 25-47
Author(s):  
Nadhira Sukmana Putri
Keyword(s):  
Performance Enhancement ◽  
Well Being ◽  
Employee Motivation ◽  
Training And Development ◽  
Employee Productivity ◽  
Employee Morale ◽  
And Performance ◽  
Beach Resort ◽  
The Impact

The purpose of this study is to examine the impact of staff facilities on employee motivation and performance by using a case-study of Oberoi Beach Resort – a five-star hotel situated in Lombok, Indonesia. This study begins with a review of the research background, aim, and objectives. The author then addressed issues in the hospitality industry and the importance of maintaining employee morale and productivity. Next, the main topics of this study, i.e. employee productivity & well-being, staff facilities, motivation, and performance were analyzed. Such topics were narrowed and established as the basis for primary research. Mixed-method approach was adopted to verify theories with acquired data. Despite several limitations, this research found that wages, events for staff, and medical-room are effective in motivating them to perform better and to stay with the brand. Additionally, training and development is the best tool for performance enhancement.

scholarly journals On the Corrosion Behaviour of Low Modulus Titanium Alloys for Medical Implant Applications: A Review

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 878 ◽  
Author(s):  
Afzali ◽  
Ghomashchi ◽  
Oskouei
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Titanium Alloys ◽  
Corrosion Behaviour ◽  
Electrochemical Corrosion ◽  
Passive Layer ◽  
Medical Implant ◽  
Low Modulus ◽  
New Generation ◽  
The Impact

The corrosion behaviour of new generation titanium alloys (β-type with low modulus) for medical implant applications is of paramount importance due to their possible detrimental effects in the human body such as release of toxic metal ions and corrosion products. In spite of remarkable advances in improving the mechanical properties and reducing the elastic modulus, limited studies have been done on the electrochemical corrosion behaviour of various types of low modulus titanium alloys including the effect of different beta-stabilizer alloying elements. This development should aim for a good balance between mechanical properties, design features, metallurgical aspects and, importantly, corrosion resistance. In this article, we review several significant factors that can influence the corrosion resistance of new-generation titanium alloys such as fabrication process, body electrolyte properties, mechanical treatments, alloying composition, surface passive layer, and constituent phases. The essential factors and their critical features are discussed. The impact of various amounts of α and β phases in the microstructure, their interactions, and their dissolution rates on the surface passive layer and bulk corrosion behaviour are reviewed and discussed in detail. In addition, the importance of different corrosion types for various medical implant applications is addressed in order to specify the significance of every corrosion phenomenon in medical implants.

Corrosion Behaviour of AISI 304 Austenitic Stainless Steel Fabricated by Equal-Channel Angular Pressing

2011 ◽  
Vol 194-196 ◽  
pp. 411-415 ◽  
Author(s):  
Guo Xing Chen ◽  
Yan Gao ◽  
Shu Hui Wu ◽  
Jin Li Hu
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Grain Refinement ◽  
Corrosion Behaviour ◽  
Corrosion Current ◽  
Open Circuit ◽  
Aisi 304 ◽  
Angular Pressing ◽  
Average Size

In this essay, the effects of grain refinement on corrosion behavior and hardness of equal-channel-angular-pressed (ECAPed) AISI 304 austenitic SS were studied. Finer grains with average size of 5μm in the specimen were obtained after four ECAPed passes compared with as-received one with grain size in range of 55μm Strain-induced grain refinement process can increase grain boundary and dislocation. Thus, the corrosion resistance of ECAPed AISI 304 austenitic SS would be improved.The refined microstructure achieves more positive open circuit potential (OCP) and lower corrosion current density in polarization corrosion tests.Through this process, austenitic stainless steel with better performance in corrosion resistance can be gained.

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