STUDI EKSPERIMENTAL PENGENDALIAN LAJU KOROSI FATIK PADA ALUMINIUM 2024-T3 DI LINGKUNGAN AIR LAUT MELALUI PENAMBAHAN INHIBITOR KALIUM KROMAT (K2CrO4)

2017 ◽  
Author(s):  
Waris Wibowo
Keyword(s):  
Aluminum Alloy ◽  
Electron Microscope ◽  
Corrosion Rate ◽  
Scanning Electron Microscope ◽  
Sea Water ◽  
Good Mechanical Property ◽  
Aluminum Alloy 2024 ◽  
Fatigue Corrosion ◽  
Al 2024 ◽  
Scanning Electron

<p>Aluminum alloy 2024-T3 is widely used in manufacturing industries such as aircraft, automotive and ship industries due to its character as a good mechanical property. Aluminum alloy2024-T3, however, is easily suffered from corrosion attack when it is applied in corrosive environment such as sea water. One of the corrosion rate control methods is by applying inhibitor addition. This research aims to study the effect of K2CrO4 inhibitor in controlling the rate of corrosion of Al 2024-T3 in sea water. In this research, K2CrO4 was added to sea water environment with various concentrations of 0.1 %, 0.3% and 0.5%. Subsequently the corrosion rates were measured using a-three-electrode potential technique with saturated calomel (Hg2Cl2) as a referenced electrode whereas the auxiliary electrode was platinum (PT). Fatigue corrosion experiments was done using servo hydraulic testing engine, sinusoidal load was chosen with the stress ratio of R= Smin/Smaks = 0,1, and the frequence of 15 Hz, the voltage level used was 20%. Composition analyses, micro structure examination with Scanning Electron Microscope (SEM) were also done to get the supporting data. The results show that fatigue corrosion rate of aluminum alloy 2024-T3 with the additions of K2CrO4 inhibitor in the sea water tends to reduce at the optimum concentration of 0.5% of K2CrO4. It is indicated by the reduction of fatigue corrosion rate as amount of 32.13%. This inhibitor may hamper the rate of fatigue corrosion by oxidation so that it produces a compound (passive film) which covers the surface of Aluminum alloy 2024-T3 which is in turn it will reduce the attack of corrosion.</p><p><strong>Keywords : Aluminum Alloy 2024-T3, Fatigue Corrosion, K2CrO4 Inhibitor</strong></p><p><br /> ABSTRAK<br /> Aluminium paduan seri 2024-T3 telah banyak diaplikasikan pada industri pesawat terbang, otomotif, dan kapal laut karena memiliki sifat mekanik yang baik. Namun demikian aluminium paduan 2024- T3 rentan terhadap korosi bila diaplikasikan di lingkungan yang korosif seperti air laut. Salah satu upaya untuk mengendalikan laju korosi adalah dengan penambahan inhibitor. Penelitian ini bertujuan untuk mempelajari pengaruh inhibitor kalium kromat (K2CrO4) dalam mengendalikan laju korosi Al 2024-T3 di lingkungan air laut. Pada penelitian ini, jenis inhibitor yang dipakai adalah kalium kromat (K2CrO4) yang ditambahkan di media air laut dengan variasi konsentrasi 0,1%; 0,3%; dan 0,5%. Selanjutnya laju korosi diukur dengan menggunakan metode sel potensial tiga elektroda yang menggunakan kalomel jenuh (Hg2Cl2) sebagai elektroda baku sedangkan elektroda tambahan digunakan platina. Pengujian korosi fatik dengan mesin uji servohidraulik, beban sinusoidal dipilih rasio tegangan R= Smin/Smaks = 0,1 dan frekuensi 15 Hz, level tegangan yang digunakan adalah 20%. Sebagai data pendukung dilakukan uji komposisi dan uji struktur mikro dengan Scanning Electron Microscope (SEM). Hasil penelitian ini memperlihatkan bahwa laju korosi fatik Al 2024-T3 dengan penambahan inhibitor kalium kromat (K2CrO4) di media air laut cenderung menurun pada konsentrasi optimum 0,5% K2CrO4, ditandai dengan penurunan laju korosi fatik sebesar 32,13%. Inhibitor ini dapat menghambat laju korosi fatik dengan cara mengoksidasi sehingga menghasilkan produk senyawa (lapisan pasif) yang dapat menutup permukaan Al 2024-T3 yang dapat mengurangi serangan korosi.</p><p><strong>Kata kunci : Aluminium Paduan 2024-T3, Korosi Fatik , Inhibitor K2CrO4</strong></p><p> </p>

An Investigation on the Impurities of Aluminum Alloy in Melt Furnace

2010 ◽  
Vol 97-101 ◽  
pp. 1045-1048
Author(s):  
Zheng Bin Xu ◽  
Yong Zhi Zou ◽  
Wen Chao Wang ◽  
Xing Zhi Pang ◽  
Jian Min Zeng
Keyword(s):  
Aluminum Alloy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Elemental Carbon ◽  
Energy Dispersive Spectrometer ◽  
Furnace Wall ◽  
Sio2 Particle ◽  
A357 Alloy ◽  
Unknown Phase ◽  
Scanning Electron

The scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) were used to characterize samples prepared from the surface scum of melt, the middle flake residues on the furnace wall and the “bottom bulk” after the A357 alloy pouring. The morphology and impurities composition of these features were investigated. Some of particles and regions in samples during the analyses were also studied in detail. The results of analyses show that the surface scum of melt include Al2O3, MgO or MgAl2O4; the impurities of the middle flake residues is comprised of Al2O3, MgO or MgAl2O4, as well as SiO2 particle, Al9Fe2Si2 compound and dimple like C-rich areas; the bottom bulk contains C-rich impurities such as Al4C3 or some of unknown phase or elemental carbon.

The Surface Deformation of Aluminum Compressed With Viscous Lubricants

1974 ◽  
Vol 96 (4) ◽  
pp. 591-594 ◽  
Author(s):  
D. D. Ratnagar ◽  
H. S. Cheng ◽  
J. A. Schey
Keyword(s):  
Aluminum Alloy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Finish ◽  
Surface Deformation ◽  
Surface Roughening ◽  
6061 Aluminum Alloy ◽  
Clear Delineation ◽  
Lubricant Viscosity ◽  
Scanning Electron

The influences of lubricant viscosity and loading velocity on the surface finish of plastically compressed 6061 aluminum alloy cylinders were studied. Specimens with polished end faces were subjected to compression between two flat, chromium plated dies, with lubricants of a viscosity ranging from 42 cp to 1207 cp at 38 deg C. The deformed surfaces were studied under a scanning electron microscope and by stylus tracings and CLA readings. With the lighter lubricants surface roughening resulted from preferential yielding leading to a clear delineation of grain boundaries and slip lines. With the heavier lubricants, localized “hydrodynamic pockets” formed in addition to the above features. The depth of pockets increased with viscosity and/or velocity.

Effects of Microporosity on the Tensile Properties of Aluminum Alloy

2011 ◽  
Vol 422 ◽  
pp. 627-631 ◽  
Author(s):  
Xie Hua Li ◽  
Li Zi He ◽  
Yi Heng Cao ◽  
Pei Zhu ◽  
Ya Ping Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hydrogen Content ◽  
Optical Microscope ◽  
Slip Step ◽  
Inclusion Content ◽  
1050 Aluminum Alloy ◽  
Scanning Electron

The influences of cooling rate, hydrogen inflating time, degassing time, inclusion content on the distribution of pores within the ingot , hydrogen content and the mechanical properties of 1050 aluminum alloy were investigated by tensile test, optical microscope(OM), scanning electron microscope(SEM). With the increasing inflating hydrogen time, the hydrogen content increases, while, the strengths and elongation decrease. With the increasing degassing time, the hydrogen content decreases, while, the strengths and the elongation increase. With increasing cast temperature, the hydrogen content remains constant at first and increases obviously from 7200C to 7600C, while the strengths and the elongation decrease gradually. The crack is mainly originated at outcrop of slip step, inclusion and porosity.

Effect of Solution Treatment on Corrosion Resistance of the Biodegradable NZ20K Alloy

2016 ◽  
Vol 849 ◽  
pp. 196-202
Author(s):  
Yang Fei ◽  
Xiao Bo Zhang ◽  
Zhi Xin Ba ◽  
Zhang Zhong Wang
Keyword(s):  
Corrosion Resistance ◽  
Electron Microscope ◽  
Corrosion Rate ◽  
Scanning Electron Microscope ◽  
Biomedical Applications ◽  
Solution Treatment ◽  
Solution Temperature ◽  
Solution Treated ◽  
Different Temperatures ◽  
Scanning Electron

In order to study the effect of solution temperature on corrosion resistance of Mg alloy for biomedical applications, microstructure and corrosion behavior of Mg-2.25Nd-0.11Zn-0.43Zr (NZ20K) alloy solution treated at different temperatures were investigated by using a scanning electron microscope (SEM) equipped with an electron dispersive spectroscope (EDS), electrochemical and mass loss tests. The results show that the grains grow and precipitations decreases with increasing the solution temperature. The corrosion rate decreases firstly and then increases with increasing solution temperature, and the best corrosion resistance of the NZ20K alloy is obtained at the temperature of 540 °C.

Mechanical Properties and Microstructure Analysis of Aluminum and Steel Dissimilar Material Weld Joint

2014 ◽  
Vol 511-512 ◽  
pp. 17-21
Author(s):  
Jian Bing Chen ◽  
Chi Peng ◽  
Dong Hai Cheng ◽  
Dong Xu Cheng ◽  
Yi Ping Chen
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Aluminum Alloy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Intermetallic Compounds ◽  
Weld Joint ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Scanning Electron

LF16 aluminum alloy and Q235 steel were brazed by Zn-Al solder and the Al-Si-Cu solder. Metallographic microscope and scanning electron microscope were used to observe the microstructure of weld joint. The result shows that the strength of the joints, which were welded with Zn-Al solder reached 133.6Mpa. Zn-rich solid solution phase and Al-rich solid solution phase existed in Zn-based solder brazing seam. The Fe element trend was gradual changed, while Al element trended more gently, and generated Fe2Al5 intermetallic compounds in the joints in both the brazing joint of Zn-based and Al-based solder.

Effect of Cerium Concentration on the Corrosion Resistance of Electro-Less Ni-P-PTFE Composite Coatings

2014 ◽  
Vol 618 ◽  
pp. 247-251
Author(s):  
Chuan Qi Fu ◽  
Fan Yong ◽  
Qing Le Zhang
Keyword(s):  
Corrosion Resistance ◽  
Electron Microscope ◽  
Corrosion Rate ◽  
Scanning Electron Microscope ◽  
Composite Coatings ◽  
Immersion Test ◽  
Carbon Steels ◽  
Rare Element ◽  
Ptfe Composite ◽  
Scanning Electron

In order to improve the corrosion resistance of electro-less Ni-P-PTFE composite coating, electro-less Ni-P-PTFE composite coatings were prepared on 45# carbon steels specimen with addition of rare element cerium (Ce). Surface morphology of the coatings was observed by scanning electron microscope (SEM). Effect of cerium concentration on PTFE content of the coatings was investigated. The results indicated that properly added cerium into the bath increases the PTFE content of the coatings, decrease the corrosion rate, made the corrosion resistance improved of the coatings. And effect of cerium concentration on corrosion resistance of the composite coatings was evaluated by immersion test with 3.5% NaCl and 5% NaOH solutions respectively. With the rare element cerium concentration exceeding, the corrosion rate gradually increase. At the cerium concentration was 0.01 g.L-1, the corrosion rate of coating in the solutions were lowest, at 0.00186 mg·cm-2·h-1and 0.00109 mg·cm-2· h-1. But with the cerium concentration go on increasing, the corrosion resistance of the coatings then decreases.

Meso-Structure Design of B4C-Al/Al Composites by Hot Pressing

2016 ◽  
Vol 849 ◽  
pp. 801-806
Author(s):  
Hui Li ◽  
Yi Tan Zhang ◽  
Kei Ameyama ◽  
Hai Jun Yang ◽  
Zhi Guo Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Electron Microscope ◽  
Powder Metallurgy ◽  
Scanning Electron Microscope ◽  
Deformation Mechanism ◽  
Mass Fraction ◽  
Structure Design ◽  
Powder Metallurgy Method ◽  
Scanning Electron

According to the theory of meso-structure design, milling powders were blended with un-milled Al particulate to increase ductility. Two kinds of Al particulate-toughened composites were fabricated by using powder metallurgy method, where the mass fraction of B4C in the B4C-Al agglomerate particles was 40%, but 32% and 16% in the whole composite. The microstructure of composites was examined by scanning electron microscope (SEM), and its mechanical properties were studied. The results indicate that Al particulate-toughened sample has a slight plasticity with bulks of aluminum alloy in the composite. But meso-structure design has no effect on improvement on the plasticity and toughness of the sample B4C-Al/Al (16%)(3#), where the mass fraction of B4C in the whole composite is 16%. In the present study, the strengthening and deformation mechanism of the composites were also discussed.

Microstructural Investigations on ATIG and FBTIG Welding of AA 2219 T87 Aluminum Alloy

2014 ◽  
Vol 592-594 ◽  
pp. 489-493 ◽  
Author(s):  
A.V. Santhana Babu ◽  
P.K. Giridharan ◽  
P. Ramesh Narayanan ◽  
S.V.S. Narayana Murty
Keyword(s):  
Aluminum Alloy ◽  
Electron Microscope ◽  
Aluminum Alloys ◽  
Scanning Electron Microscope ◽  
Key Words ◽  
Energy Dispersive Spectroscopy ◽  
Welding Process ◽  
Microstructural Investigation ◽  
Cracking Tendency ◽  
Scanning Electron

Limitation in penetration depth is a concern in conventional TIG welding process. To improve penetration capability of TIG process, both Activated TIG (ATIG) and Flux Bounded TIG (FBTIG) are investigated in aluminum alloy AA 2219 T87. Undesirable arc wandering and cracking tendency are observed in ATIG welds. Microstructural investigation reveals ATIG welds are prone for liquation cracks. Morphology of the cracks along with the attributable factors are explained with optical and SEM (Scanning Electron Microscope) micrographs. Energy Dispersive Spectroscopy (EDS) results are also presented to explain the solute enrichment in the grain boundaries of the ATIG welds. FBTIG is found to produce good quality welds and is more suitable for welding aluminum alloys. Key words: Flux Assisted TIG; ATIG; FBTIG; Penetration Improvement; Microstructure; AA2219.

Microstructure and Porous Defects of a Spray-Formed and Hot Worked 7000 Aluminum Alloy

2016 ◽  
Vol 879 ◽  
pp. 1778-1782
Author(s):  
Shu Hui Huang ◽  
Zhi Hui Li ◽  
Bai Qing Xiong ◽  
Yon Gan Zhang ◽  
Xi Wu Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hot Isostatic Pressing ◽  
Aging Treatment ◽  
Hot Extrusion ◽  
Evolution Of Microstructure ◽  
Scanning Electron

The evolution of microstructure and porous defects of a spray-formed 7000 Aluminum alloy is researched in this paper. The spray-formed alloy is treated by hot isostatic pressing (HIP), homogenization, hot extrusion, solution and aging treatment. Metallographic microscope, scanning electron microscope (SEM) and tensile test are used to research the microstructure and mechanical properties. The results show that, there are two kinds of porous defects in spray-formed alloy, which has gas and no gas. The porous defects of spray-formed ingot can be mostly eliminated by HIP and hot extrusion. After solution and aging treatment, the tensile strength and elongation reach 757MPa and 10.2%, respectively.

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