Estimation of fatigue evolution of aluminum alloy plated with electroless NI–CO–P by using electromagnetic impedance method

Purpose This paper aims to investigate the structural, corrosion and the study of tribocorrosion features of the AA7075 aluminum alloy with and without the application of electroless Ni-P/Ni-B duplex coating with a thickness of approximately 40 microns. Design/methodology/approach Surface characterization of the samples was made by structural surveys (light optic microscope, scanning electron microscopic examinations and X-ray diffraction analyses), hardness measurements, corrosion and tribocorrosion tests. Findings Results of the experiments showed that upper Ni-B coating deposited on the surface of first Ni-P layer by duplex treatment caused remarkable increment in the hardness, corrosion resistance and tribocorrosion performance as compared to the AA7075 aluminum alloy. Originality/value This study can be a practical reference and offers insight into the effects of duplex treating on the increase of hardness, corrosion and tribocorrosion performance.

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Electroless Ni-La-P Coatings on 2024 Aluminum Alloys for Aircraft Structure

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.224.348 ◽

2012 ◽

Vol 224 ◽

pp. 348-351

Author(s):

Chuan Yong Huang

Keyword(s):

Aluminum Alloy ◽

Aluminum Alloys ◽

Aluminium Alloys ◽

Ph Value ◽

Deposition Method ◽

Aircraft Structure ◽

Corrosion Resistant ◽

Effects Of Ph ◽

Alloy Plating ◽

Electroless Ni

2024 aluminium alloys are widely used in airframe construction.However,this series of alloys are susceptible to corrosion to limit their usefulness,In this study,electroless Ni-La-P alloy plating on aluminum alloy and the effects of pH value,temperature and concentration of LaNiO3 on deposition rate were investigated.Surface morphology and corosion-resistant of the electroless Ni-La-P deposits were evaluated.The results showed the corrosion-resistant in 5％ NaC1 solutions obviously enhance compared with original aluminum alloy using electroless Ni-La-P deposition method．

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The Evolution of Texture During Annealing of Nanocrystalline Electroless Nickel Alloy Deposits

Textures and Microstructures ◽

10.1155/tsm.34.181 ◽

2000 ◽

Vol 34 (2-3) ◽

pp. 181-195 ◽

Cited By ~ 7

Author(s):

Dong Nyung Lee ◽

Kang-Heon Hur

Keyword(s):

Aluminum Alloy ◽

Sodium Citrate ◽

Thermal Strain ◽

Electroless Nickel ◽

Alloy Sheet ◽

Aluminum Alloy Sheet ◽

Preferential Growth ◽

Alloy Films ◽

Texture Change ◽

Electroless Ni

The electroless Ni–Co–P alloy films containing up to 13.4% Co and 7.6% P were deposited on a 5086 aluminum alloy sheet using baths consisting of NiSO4, CoSO4, (NH4)2SO4, NaH2PO2, sodium citrate and thiourea. The deposits were solid solutions having a grain size of 6–7 nm and strong 〈111〉 texture. When the deposits were annealed for 2 h, Ni5P2 was precipitated at 325°C and transformed into the stable Ni3P phase at higher temperatures. During annealing the texture of deposit changed from 〈111〉 to 〈100〉. The texture change was attributed to preferential growth of 〈100〉 grains at the expense of 〈111〉 grains to decrease the thermal strain energy of the deposits. On the other hand, the electroless Ni–Cu–P alloy films containing Cu and P deposited on 5086 aluminum alloy sheet had the microstructures and textures which are similar to these of the Ni–Co–P alloy films. However, their initial 〈111〉 texture remained relatively stable even after annealing. The differences in annealing textures of Ni–Co–P and Ni–Cu–P alloy films have been discussed.

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Effect of Zincate Treatment on Adhesion of Electroless Ni–P Plated Film for 2017 Aluminum Alloy

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.46.2169 ◽

2005 ◽

Vol 46 (10) ◽

pp. 2169-2175 ◽

Cited By ~ 20

Author(s):

Makoto Hino ◽

Koji Murakami ◽

Minoru Hiramatsu ◽

Keiko Chen ◽

Atsushi Saijo ◽

...

Keyword(s):

Aluminum Alloy ◽

Electroless Ni

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Effect of Phenyl Thiourea as a Stabilizer on Electrochemical Properties of Electroless Ni-P Coatings on 6063 Aluminum Alloy

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1095.2013.20337 ◽

2013 ◽

Vol 30 (6) ◽

pp. 683

Author(s):

Huicheng YU ◽

Yichun WEI ◽

Yanyan HAN

Keyword(s):

Aluminum Alloy ◽

Electrochemical Properties ◽

6063 Aluminum Alloy ◽

Electroless Ni

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Preparation of Electroless Nickel-Phosphorous-TiO2 Composite Coating for Improvement of Wear and Stress Corrosion Cracking Resistance of AA7075 in 3.5% NaCl

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.656-657.74 ◽

2015 ◽

Vol 656-657 ◽

pp. 74-79 ◽

Cited By ~ 3

Author(s):

Cheng Kuo Lee ◽

Chung Sheng Chang ◽

An Hung Tan ◽

Ching Yi Yang ◽

Sheng Long Lee

Keyword(s):

Aluminum Alloy ◽

Stress Corrosion ◽

Composite Coating ◽

Stress Corrosion Cracking ◽

Pitting Corrosion ◽

Corrosion Cracking ◽

Boiling Water ◽

Cracking Resistance ◽

Electroless Ni ◽

Sealing Treatment

In this study nanoTiO2 particles were incorporated into the electroless plating solution to prepare Ni-P-TiO2 composite coating on anodized AA7075 aluminum alloy to improve the wear and stress corrosion cracking resistance of the coated alloy in 3.5%NaCl solution. The anodized AA7075 aluminum alloy was also performed by a boiling water sealing treatment for comparison. The wear and stress corrosion cracking (SCC) characteristics were investigated using a self-designed block-on-ring machine and slow strain rate test. The effect of corrosion was evaluated by electrochemical polarization measurements. The surface morphology, element composition and surface hardness of the coating were analyzed by scanning electron microscopy (SEM), X-ray energy dispersive spectrometry (EDS) and Vicker′s hardness tester. Experimental results indicated that after boiling water sealing treatment the resistance properties of the anodized AA7075 aluminum alloy were further improved. The anodizing treatment of AA7075 aluminum alloy gave a thick film with high porosity. The porous film efficiently improved the cohesion, adhesion and hardness of the electroless Ni-P composite coating. Therefore, the electroless Ni-P composite coating deposited on the anodized AA7075 aluminum alloy offered a superior wear, pitting corrosion and stress corrosion cracking resistance properties than both anodizing and sealing treatment. By comparison with Ni-P and Ni-P-TiO2 coatings the incorporation of TiO2 resulted in a more uniform and crack-free surface structure of the composite coating. This is responsible for the higher hardness, better wear, pitting corrosion and stress corrosion cracking resistance of the electroless Ni-P-TiO2 coating.

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