scholarly journals EFFECT OF AL2O3 NANOPARTICLES ON CORROSION BEHAVIOR OF ALUIMNUM ALLOY (AL-4.5 WT% CU-1.5 WT% MG) FABRICATED BY POWDER METALLURGY

2019 ◽  
Vol 11 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Muna Khethier Abbass ◽  
Bassma Finner Sultan
Keyword(s):  
Powder Metallurgy ◽  
Corrosion Behavior ◽  
Base Alloy ◽  
Compaction Pressure ◽  
Electrochemical Corrosion ◽  
Anodic Polarization Curve ◽  
Alumina Nanoparticles ◽  
Al2o3 Nanoparticles ◽  
Micro Hardness ◽  
Cyclic Polarization

In this research the effect of Al2O3 nanoparticles on corrosion behavior of aluminum base alloy (Al-4.5 wt% Cu-1.5 wt% Mg) has been investigated. Nanocomopsites reinforced with variable contents of 1, 3 and 5 wt% of Al2O3 nanoparticles were fabricated using powder metallurgy. All samples were prepared from the base alloy powders under the best powder metallurgy processing conditions of 6 hr of mixing time, 450 MPa of compaction pressure and 560 °C of sintering temperature. Density and micro hardness measurements, and electrochemical corrosion tests are performed for all prepared samples in 3.5 wt% NaCl solution at room temperature using potentiostate instrument. It has been found that density and micro hardness of the nanocomposite increase with increasing of wt% Al2O3 nanoparticles to Al matrix. It was found from Tafel extrapolation method that corrosion rates of the nanocomposites reinforced with alumina nanoparticles were lower than that of base alloy. From results of corrosion test by potentiodynamic cyclic polarization method, it was found the pitting corrosion resistance improves with adding of Al2O3 nanoparticles. It was noticed that the pits disappear and the hysteresis loop disappears also from anodic polarization curve.

Influence of electrosynthesis conditions and Al2O3 nanoparticles on corrosion protection effect of polypyrrole films

2014 ◽  
Vol 61 (3) ◽  
pp. 146-152 ◽  
Author(s):  
Ali Ehsani ◽  
Mohammad Ghasem Mahjani ◽  
Maryam Nasseri ◽  
Majid Jafarian
Keyword(s):  
Oxygen Reduction ◽  
Corrosion Protection ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Reduction Process ◽  
Artificial Seawater ◽  
Alumina Nanoparticles ◽  
Al2o3 Nanoparticles ◽  
Active Dissolution ◽  
Content Type

Purpose – The purpose of this paper was to investigate the anti-corrosion behavior of polypyrrole (PPy) films in different states and presence of alumina nanoparticles synthesized by galvanostatic electropolymerization on stainless steel (SS) electrodes in an artificial seawater solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Design/methodology/approach – The electrochemical measurements were used to examine the effects of PPy and its nanocomposite on the corrosion behavior of SS type 316L in artificial seawater. A standard electrochemical cell with three electrodes was used for the measurements. The electrochemical response of the coated electrodes in the doped and the undoped state was compared with that of a bare electrode. Corrosion rate information was obtained by the Tafel extrapolation method, where the intersection point of a cathodic and an anodic polarization curve provides both the corrosion potential and the corrosion current. EIS measurements confirmed the potentiodynamic and open circuit potential (OCP) results. The microstructure of the obtained films was investigated by scanning electron microscopy. Findings – The results showed that the coated polymer films shifted the electrode potential toward more positive potentials, but this shift did not lead to passivation. However, a notable synergy was observed between PPy undoped film, oxygen reduction and iron dissolution. The potential of the SS remained in the active dissolution region, and it was not possible to produce a passive oxide layer in this region. PPy separates the metal dissolution process from the oxygen reduction process. This would prevent the local pH increase at the metal surface and subsequent delamination. The polarization curves, EOCP and impedance measurements showed that PPy undoped/Al2O3 layers show promise as good candidates for the corrosion protection of reactive metals. Originality/value – This paper presents that electrodes coated with undoped PPy synthesized in the presence of dodecyl sulfate anions and Al2O3 nanoparticles offered a noticeable enhancement of protection against corrosion processes.

scholarly journals Preparation, microstructure and property of zinc-substituted hydroxyapatite/magnesium biocomposite

2017 ◽  
Vol 49 (4) ◽  
pp. 399-407 ◽  
Author(s):  
Zhengquan Jia ◽  
Zuoxing Guo ◽  
Qiulin Wei ◽  
Jingjuan Li ◽  
Liang Zhao ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Crystallite Size ◽  
Corrosion Behavior ◽  
Electrochemical Corrosion ◽  
Compression Tests ◽  
Corrosion Tests ◽  
Electrochemical Corrosion Behavior ◽  
Optimal Mechanical Property

Zinc-substituted hydroxyapatite (Zn-HA, Ca10-xZnx(PO4)6(OH)2) is used as the modified material of hydroxyapatite (HA, Ca10 (PO4)6(OH)2). In this work, Zn-HA with Zn contents of 10-30 mol% was used to produce Zn-HA/Mg composites by powder metallurgy. The calculated results showed that the crystallite size and lattice parameters of Zn-HA powders varied with the contents of 0-30 mol% Zn, confirming that the divalent Zn2+ ions can substitute Ca2+ ions in HA. Furthermore, the microstructure, mechanical property and electrochemical corrosion behavior of Zn-HA/Mg composites were investigated by SEM, compression tests, and electrochemical corrosion tests, respectively. The results indicate that the highest density and lowest porosity are obtained and the optimal mechanical property and corrosion resistance are achieved in the Zn-HA/Mg composites with 20 mol% Zn.

scholarly journals Electrochemical Corrosion Behavior of Pure Mg Processed by Powder Metallurgy

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 986
Author(s):  
Jozef Minda ◽  
Stanislava Fintová ◽  
Branislav Hadzima ◽  
Pavel Doležal ◽  
Michaela Hasoňová ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Corrosion Products ◽  
Uniform Corrosion ◽  
Electrochemical Corrosion Behavior ◽  
Powder Particles ◽  
Mechanical Bonding

Pure Mg samples were prepared by powder metallurgy using the cold and hot compacting methods. Cold compacted pure Mg (500 MPa/RT) was characterized by 5% porosity and the mechanical bonding of powder particles. Hot compacted samples (100 MPa/400 °C and 500 MPa/400 °C) exhibited porosity below 0.5%, and diffusion bonding combined with mechanical bonding played a role in material compaction. The prepared pure Mg samples and wrought pure Mg were subjected to corrosion tests using electrochemical impedance spectroscopy. Similar material corrosion behavior was observed for the samples compacted at 500 MPa/RT and 100 MPa/400 °C; however, hot compacted samples processed at 500 MPa/400 °C exhibited longer corrosion resistance in 0.9% NaCl solution. The difference in corrosion behavior was mainly related to the different binding mechanisms of the powder particles. Cold compacted samples were characterized by a more pronounced corrosion attack and the creation of a porous layer of corrosion products. Hot compacted samples prepared at 500 MPa/400 °C were characterized by uniform corrosion and the absence of a layer of corrosion products on the specimen surface. Powder-based cold compacted samples exhibited lower corrosion resistance compared to the wrought pure Mg, while the corrosion behavior of the hot compacted samples prepared at 500 MPa/400 °C was similar to that of wrought material.

Enhanced Hardness Property in the Development of Al-TiC Composites through P/M Techniques

2012 ◽  
Vol 548 ◽  
pp. 243-249
Author(s):  
Anand S. Solay ◽  
B. Mohan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Powder Metallurgy ◽  
Compaction Pressure ◽  
Weight Percent ◽  
Processing Parameters ◽  
Vital Role ◽  
Micro Hardness ◽  
Hardness Property ◽  
6061 Aluminium Alloy

Powder Metallurgy is a continually and rapidly evolving technology, embracing most metallic and alloy materials with a variety of shapes. Weight percent of reinforcements and processing parameters plays a vital role in determining strength of the powder metallurgical parts. In this work, the effect of varying weight percent of particulate TiC reinforcement with elemental 6061 Aluminium alloy on mechanical properties of specimens processed through powder metallurgy has been investigated. Weight percent of TiC ranges from 1% to 10% and the specimens are compacted at 125 MPa and 175 MPa. With increase in the weight percent of TiC up to 5%, micro hardness and tensile strength value increases and there is a decrease in tensile strength value for a weight percent of 10 % TiC. Increase in compaction pressure from 125 MPa to 175 MPa, the density, hardness and tensile strength value increases.

Fabrication and Characterisation of Powder Metallurgy Fe-Cr Matrix Composites Reinforced with Al2O3

2013 ◽  
Vol 686 ◽  
pp. 157-163
Author(s):  
Saidatulakmar Shamsuddin ◽  
Shamsul Baharin Jamaludin ◽  
Zuhailawati Hussain ◽  
Zainal Arifin Ahmad
Keyword(s):  
Wear Resistance ◽  
Compressive Strength ◽  
Powder Metallurgy ◽  
Sintering Temperature ◽  
Compaction Pressure ◽  
Powder Metallurgy Method ◽  
Matrix Composites ◽  
Micro Hardness ◽  
Sintered Powder ◽  
The Matrix

Abstract. Sintered powder metallurgy Fe based composites with advanced mechanical properties have been proposed as substitutes for more expensive cemented carbide and wrought alloys in many applications, especially as inexpensive wear resistance parts. The aim of this work was to fabricate and characterize a composite made of Fe-Cr as the matrix and Al2O3 particles as reinforcement. The composite was made by powder metallurgy method. The effect of different amount of binder, mixing duration, compaction pressure and sintering temperature has been investigated. Densification, micro hardness, wear resistance and compressive strength were used to characterize the composite. Powder metallurgy parameters that satisfy the composites quality have been optimized and result showed that higher sintering temperatures promote good sintering in the composites which produced better densification, higher reading of micro hardness, better wear resistance and compressive strength.

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