Preparation and properties of the anodized film on Fe-Cr-Al alloy surface

2020 ◽  
Vol 67 (4) ◽  
pp. 379-386
Author(s):  
Jialin Yang ◽  
Yunting Guo ◽  
Wei Zai ◽  
Siyuan Ma ◽  
Liang Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ethylene Glycol ◽  
Anodic Oxidation ◽  
Current Density ◽  
Oxidation Process ◽  
Electrochemical Impedance ◽  
Oxidation Mechanism ◽  
Oxidation Time ◽  
Al Alloy ◽  
Content Type

Purpose This paper aims to find a way to improve the surface insulation, corrosion resistance and mechanical properties of Fe-Cr-Al electrothermal alloy, exploring the best oxidation condition and analyzing the oxidation mechanism. Design/methodology/approach Electrochemical workstation was used for anodic oxidation, and the effect of current density, ethylene glycol concentration and oxidation time on properties of the film were investigated by resistivity test, scanning electron microscope, electrochemical tests (potentiodynamic polarization and electrochemical impedance spectroscopy) and mechanical tests, and the oxidation process was analyzed by X-ray photoelectron spectroscopy (XPS). Findings According to the potential-time curves of anodic oxidation and the analysis of XPS, the whole oxidation process can be divided into four stages. When the current density is 0.8 A/dm2, the ethylene glycol concentration is 10%, and the oxidation time is 60 min, the film has the best corrosion protection, mechanical properties and surface morphology. The resistivity of the samples is about 13 orders magnitude than that of the matrix. Originality/value In this paper, a protective electrically insulating film was prepared by anodic oxidation in an alkaline electrolyte solution. The oxidation conditions were optimized and the oxidation mechanism was analyzed.

Influence of ageing treatment on microstructure, mechanical properties and adhesive wear behaviour of 6063 aluminium alloy

2014 ◽  
Vol 66 (4) ◽  
pp. 520-524 ◽  
Author(s):  
Serkan Büyükdoğan ◽  
Süleyman Gündüz ◽  
Mustafa Türkmen
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
High Speed ◽  
Al Alloys ◽  
Wear Behaviour ◽  
Al Alloy ◽  
Strain Ageing ◽  
Content Type ◽  
Static Strain ◽  
Structural Applications

Purpose – The paper aims to provide new observations about static strain ageing in aluminium (Al) alloys which are widely used in structural applications. Design/methodology/approach – The present work aims to provide theoretical and practical information to industries or researchers who may be interested in the effect of static strain ageing on mechanical properties of Al alloys. The data are sorted into the following sections: introduction, materials and experimental procedure, results and discussion and conclusions. Findings – Tensile strength, proof strength (0.2 per cent) and percentage elongation measurement were used to investigate the effect of strain ageing on the mechanical properties. Wear tests were performed by sliding the pin specimens, which were prepared from as-received, solution heat-treated, deformed and undeformed specimens after ageing, on high-speed tool steel (64 HRC). It is concluded that the variations in ageing time improved the strength and wear resistance of the 6063 Al alloy; however, a plastically deformed solution-treated alloy has higher strength and wear resistance than undeformed specimens for different ageing times at 180°C. Practical implications – A very useful source of information for industries using or planning to produce Al alloys. Originality/value – This paper fulfils an identified resource need and offers practical help to the industries.

Corrosion characterization of Sn-Zn solder: a review

2019 ◽  
Vol 31 (1) ◽  
pp. 52-67 ◽  
Author(s):  
Muhammad Firdaus Mohd Nazeri ◽  
Muhamad Zamri Yahaya ◽  
Ali Gursel ◽  
Fakhrozi Cheani ◽  
Mohamad Najmi Masri ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Alloy System ◽  
Future Research ◽  
Corrosion Properties ◽  
Content Type ◽  
Characterization Techniques ◽  
Recent Developments ◽  
Potentiostatic Polarization

PurposeThe purpose of this paper is to review and examine three of the most common corrosion characterization techniques specifically on Sn-Zn solders. The discussion will highlight the configurations and recent developments on each of the compiled characterization techniques of potentiodynamic polarization, potentiostatic polarization and electrochemical impedance spectroscopy (EIS).Design/methodology/approachThe approach will incorporate a literature review of previous works related to the experimental setups and common parameters.FindingsThe potentiostatic polarization, potentiodynamic polarization and EIS were found to provide crucial and vital information on the corrosion properties of Sn-Zn solders. Accordingly, this solder relies heavily on the amount of Zn available because of the inability to produce the intermetallic compound in between the elements. Further, the excellent mechanical properties and low melting temperature of the Sn-Zn solder is undeniable, however, the limitations regarding corrosion resistance present opportunities in furthering research in this field to identify improvements. This is to ensure that the corrosion performance can be aligned with the outstanding mechanical properties. The review also identified and summarized the advantages, recent trends and important findings in this field.Originality/valueThe unique challenges and future research directions regarding corrosion measurement in Sn-Zn solders were shown to highlight the rarely discussed risks and problems in the reliability of lead-free soldering. Many prior reviews have been undertaken of the Sn-Zn system, but limited studies have investigated the corrosive properties. Therefore, this review focuses on the corrosive characterizations of the Sn-Zn alloy system.

Corrosion behavior of in situ (TiC-TiB2)p/AZ91 magnesium matrix composites in Harrison solution

2014 ◽  
Vol 61 (5) ◽  
pp. 319-327 ◽  
Author(s):  
Mohamed Gobara ◽  
Mohamed Shamekh
Keyword(s):  
Mechanical Properties ◽  
Corrosion Behavior ◽  
Matrix Composite ◽  
Electrochemical Impedance ◽  
Magnesium Matrix Composite ◽  
Magnesium Matrix ◽  
Content Type ◽  
X Ray ◽  
Az91 Magnesium

Purpose – This paper aims to study both the mechanical properties and the corrosion behavior of the synthesized in situ (TiC-TiB2) particulates/AZ91 magnesium matrix composite and compare the results with that of the conventional AZ91D alloy. Design/methodology/approach – Scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were used to study the surface morphology and crystalline structure. Mechanical compression tests were used to investigate the mechanical performance according to ASTM E9-89a. The corrosion behavior of the synthesized magnesium alloy was examined using both electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques in dilute Harrison solutions. Findings – The microstructure of the Mg composite showed a uniform distribution of reinforcing phases. Also, the reinforcing phases were formed without residual intermediate phases. The addition of titanium and boron carbides not only enhanced the mechanical properties of the matrix but also improve its corrosion behavior. Originality/value – This is the first time that magnesium matrix composite has been to synthesized with TiC and TiB2 particulates starting from starting from Ti and B carbides powder without adding aluminium using practical and low-cost technique (in situ reactive infiltration technique). This paper studies the corrosion behavior of synthesized Mg matrix in dilute Harrison solution and compares the results with that of conventional AZ91D.

Effect of aluminium content and processing parameters on the microstructure and mechanical properties of laser powder-bed fused magnesium-aluminium (0, 3, 6, 9wt%) powder mixture

2019 ◽  
Vol 25 (4) ◽  
pp. 744-751 ◽  
Author(s):  
Xiaomiao Niu ◽  
Hongyao Shen ◽  
Guanhua Xu ◽  
Linchu Zhang ◽  
Jianzhong Fu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Powder Mixture ◽  
Processing Parameters ◽  
Al Alloy ◽  
Content Type ◽  
Powder Bed ◽  
Al Content ◽  
Microstructure And Mechanical Properties ◽  
Al Powder

Purpose Mg-Al powder mixture was used to manufacture Mg-Al alloy by laser powder bed fusion (LPBF) process. This study aims to investigate the influence of initial Al content and processing parameters on the formability, microstructure and consequent mechanical properties of the laser powder bed fused (LPBFed) component. Design/methodology/approach In this study, Al powder with different weight ratio ranged from 3 to 9 per cent was mixed with pure Mg powder, and the powder mixture was processed using different LPBF parameters. Microstructure and compressive properties of the LPBFed components were examined. Findings It was found that the presence of Al significantly modified the microstructure and improved the mechanical properties of the LPBFed components. Higher volume of ß-Al12Mg17 precipitates was produced at higher initial Al content and higher laser energy density. For this reason, the a-Mg was significantly refined and the compressive strength was improved. The highest yield compressive strength achieved was 279 MPa when using Mg-9 Wt. % Al mixture. Originality/value This work demonstrates that LPBF of Mg-Al powder mixture was a viable way to additively manufacture Mg-Al alloy. Both Al content and processing parameters can be modified to control the microstructure and mechanical properties of the LPBFed components.

Frost resistance of roller compacted concrete in airport runway subjected to ethylene glycol solution

2019 ◽  
Vol 66 (1) ◽  
pp. 40-44 ◽  
Author(s):  
Wuman Zhang ◽  
Jingsong Zhang ◽  
Shuhang Chen
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Ethylene Glycol ◽  
Immersion Test ◽  
Bending Test ◽  
Content Type ◽  
Freeze Thaw ◽  
Roller Compacted Concrete ◽  
Practical Engineering ◽  
Airport Runway

Purpose Ethylene glycol (EG) solution is a common deicing fluid of the aircrafts. Roller compacted concrete (RCC) used in the runway and the parking apron will be subjected to freeze-thaw cycles in EG solution. The purpose of this study is to find whether RCC can be damaged by the action of freeze-thaw cycles or long-term immersion in EG solution. Design/methodology/approach Freeze-thaw cycles test and immersion test in EG solution by weight were used to accelerate the degradation of RCC. A compression test and a three-point bending test were carried out in the laboratory to evaluate mechanical properties of RCC. The changes of microstructure were monitored by using scanning electron microscopy and energy-dispersive X-ray analysis. Findings The results show that RCC specimens have little weight change in both freeze-thaw cycles test and immersion test. The dynamic modulus of elasticity, the compressive strength and the flexural strength of RCC with 250 freeze-thaw cycles in EG solution are decreased by 4.2, 15 and 39 per cent, respectively. The compressive strength is decreased by 35 per cent after 12 months of immersion in EG solution. Micro-cracks occur and increase with the increase in freeze-thaw cycles and immersion test. Originality/value The mass ratio of the elements in the crystal is very close to the proportion of elements in CaC2O4 (C:O:Ca = 1:1.26:1.6). More attention should be paid to using EG in practical engineering because both the freeze-thaw cycles and the complete immersion in EG solution damage the mechanical properties of RCC.

The influence of binary pozzolanic replacements on the durability and corrosion performance of reinforced concrete

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Essam Mossalam ◽  
Nivin M. Ahmed ◽  
Eglal M.R. Souaya ◽  
Basil El-Sabbagh
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Reinforced Concrete ◽  
Silica Fume ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Industrial Wastes ◽  
Content Type ◽  
Concrete Properties ◽  
Durability Of Concrete

Purpose The purpose of this research is to study the physical and mechanical properties beside the durability of concrete as well as corrosion resistance of reinforced concrete by replacing Ordinary Portland cement (OPC) with different ratios of silica fume and meta-kaolin and applying two paint formulations to enhance corrosion resistance and mechanical properties. In this work, modified concrete mixes containing pozzolanic materials of industrial wastes such as silica fume (SF) with ratios ranging between (0, 10 and 15%) and calcined raw material such as meta-kaolin (MK) with ratios (0, 3, 5 and 10%), were introduced using water binder ratio (w/b) 0.45 to study their effect on the physico-mechanical properties and durability of concrete as well as corrosion protection performance of reinforced concrete. Two paint formulations containing the same ingredients except that one of them is free from talc (G1) and the other contains talc (G2) were applied on the rebars embedded in these modified mixes. Talc is known to offer high pH to the surrounding media. Design/methodology/approach Modified concrete mixes containing the coated reinforced concrete steel with the different paint formulations in presence and absence of talc were tested, and the corrosion behavior was studied using electrochemical impedance spectroscopy (EIS) in 3.5% NaCl, and the concrete mixes were also tested through their compressive strength, chloride permeability, scanning electron microscope/energy dispersive X-ray analysis and bond strength. Findings The results revealed that the hardened reinforced concrete mix containing 10% SF with 5% MK with embedded rebars coated with G2 (paint containing talc) was the best concrete system which offers concrete sustainability besides high corrosion protection performance, i.e. presence of talc in the paints combined with the effect of cement blended with SF and MK showed positive effect on the reinforced concrete properties that leads to more durability and workability. Originality/value The integrity of using two efficient methods of corrosion protection beside the effect of the different replacements in concrete mixes containing coated reinforced concrete steel with paint formulations free from talc (G1) and others containing talc (G2), which lead to fatal changes in the pH of the surrounding media (i.e. concrete which has high alkaline pH) to achieve good concrete properties aside with convenient paint formulations together.

Synthesis and characterization of 7075 Al alloy–SiC composites

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rajesh Kumar Bhushan
Keyword(s):  
Mechanical Properties ◽  
Electron Probe ◽  
Microscopic Analysis ◽  
Casting Process ◽  
Stir Casting ◽  
Al Alloy ◽  
X Ray Diffraction ◽  
Content Type ◽  
X Ray ◽  
7075 Al Alloy

PurposeMechanical properties are highly sensitive to the microstructure, and these are indirectly related to solidification parameters and processing conditions. AA7075 possesses lightweight and excellent properties as structural material which can be optimized with SiCp addition and a good fabrication technique.Design/methodology/approach7000 series aluminium alloys exhibit the highest mechanical properties. They are used for high-strength structural applications such as aircraft parts and sporting goods. The desirable properties of these alloys are: low density, high stiffness, specific strength, good wear resistance and creep resistance. The focus of this work is to investigate the microstructure of composites formed by the dispersion of silicon carbide particles (SiC) into AA7075 by stir casting processes. 7075 Al alloy is reinforced with 10 and 15 wt.% SiCp of size 10–20 µm by stir casting process. The composites have been characterized by X-ray diffraction and scanning electron microscopy, differential thermal analysis and electron probe microscopic analysis.FindingsSiCp distribution and interaction with AA7075 matrix have been studied. AA7075/10 wt.%/SiCp (10–20 µm) and AA7075/15 wt.%/SiCp (10–20 µm) composites microstructure showed excellent SiCp distribution into AA7075 matrix. In addition, no evidence of secondary chemical reactions has been observed in X-ray diffraction and electron probe microscopic analysis.Originality/valueLittle experimental work has been reported so far about effect of addition of 10 and 15 wt.% SiCp of size (10–20 µm) on the microstructure of 7075 Al alloy fabricated by stir casting process. The present investigation has been carried out to study the microstructure and carry out XRD, DTA and EPMA analysis of 7075 Al alloy, 10 and 15 wt.% SiCp of size (10–20 µm) composite and detect the interfacial reactions with the objective to minimize the formation of Al4C3.

scholarly journals Effect of the Electrolyte Temperature and the Current Density on a Layer Microhardness Generated by the Anodic Aluminium Oxidation

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Emil Spišák ◽  
Miroslav Gombár ◽  
Ján Kmec ◽  
Alena Vagaská ◽  
Erika Fechová ◽  
...  
Keyword(s):  
Growth Rate ◽  
Chemical Composition ◽  
Anodic Oxidation ◽  
Current Density ◽  
Vickers Microhardness ◽  
Surface Current ◽  
Oxidation Time ◽  
Electrolyte Temperature ◽  
Current Densities ◽  
Oxalic Acids

The paper investigates the influence of the chemical composition and temperature of electrolyte, the oxidation time, voltage, and the current density on Vickers microhardness of aluminium oxide layers, at the same time. The layers were generated in the electrolytes with different concentrations of sulphuric and oxalic acids and surface current densities 1 A·dm−2, 3 A·dm−2, and 5 A·dm−2. The electrolyte temperature varied from −1.78°C to 45.78°C. The results have showed that while increasing the electrolyte temperature at the current density of 1 A·dm−2, the increase in the layer microhardness values is approximately by 66%. While simultaneously increasing the molar concentration of H2SO4in the electrolyte, the growth rate of the microhardness value decreases. At the current density of 3 A·dm−2, by increasing the electrolyte temperature, a reduction in the microhardness of the generated layer occurs with the anodic oxidation time less than 25 min. The electrolyte temperature is not significant with the changing values of the layer microhardness at voltages less than 10.5 V.

Anodic Oxidation Parameters on Al-Cu Alloy Anodizing Film's Electrochemical Ability by EIS

2006 ◽  
Vol 11-12 ◽  
pp. 665-668
Author(s):  
Chao Guo ◽  
Yu Zuo ◽  
Jing Mao Zhao ◽  
Xu Hui Zhao ◽  
Jin Ping Xiong
Keyword(s):  
Anodic Oxidation ◽  
Porous Layer ◽  
Current Density ◽  
Barrier Layer ◽  
Oxidation Time ◽  
Equivalent Circuits ◽  
Anodic Current Density ◽  
Anodic Current ◽  
Cu Alloy ◽  
Oxidation Parameters

EIS is used in this paper to study the effects of anodic oxidation parameters on the film’s ability, and multi-layer equivalent circuits are proposed. The oxidation time has great effect on porous layer, the porous layer’s impedance increases as the anodic oxidation time prolong; anodic current density has effect on both barrier layer and porous layer, higher current density gets higher impedance values in both barrier layer and porous layer; anodic oxidation temperature has great effect on barrier layer, when the temperature decreases, the barrier layer’s impedance increases.

High Temperature Oxidation Behavior of the B4C/BN Composites

2010 ◽  
Vol 105-106 ◽  
pp. 133-136
Author(s):  
Tao Jiang ◽  
Zhi Hao Jin ◽  
Jian Feng Yang ◽  
Guan Jun Qiao
Keyword(s):  
Mechanical Properties ◽  
Oxidation Resistance ◽  
Oxidation Process ◽  
Oxidation Time ◽  
Oxidation Temperature ◽  
Temperature Oxidation ◽  
Good Oxidation Resistance ◽  
Oxidation Processes ◽  
Ceramics Matrix ◽  
High Temperature Oxidation Behavior

The B4C/BN composites were fabricated by hot-pressing process. The microstructure, mechanical properties and oxidation resistances of the B4C/BN composites were investigated. It was shown that the h-BN particles were distributed in the B4C ceramics matrix. The mechanical properties of the B4C/BN microcomposites and the B4C/BN nanocomposites decreased gradually with the increasing content of h-BN. The mechanical properties of the B4C/BN nanocomposites were significantly improved in comparison with the B4C/BN microcomposites. The oxidation processes were performed at 1000oC, 1100oC, 1200oC, 1300oC for 20h. The oxidation curves of the B4C monolith, the B4C/BN microcomposites and the B4C/BN nanocomposites decreased gradually with the increase of oxidation temperature and oxidation time. The specimen’s weight and the oxidation resistance decreased gradually with the increase of oxidation temperature and oxidation time. The specimens remained good oxidation resistance at 1000oC; the oxidation resistance decreased remarkably at 1300oC. The decreasing specimen’s weight was attributed to the evaporation of B2O3 which produced by oxidation process of B4C and h-BN. The phase composition and microstructure of specimen’s surface after oxidation process were investigated by XRD and SEM.

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