Optimizing of Pretreatment Process of Electroless Ni-P Plating on AZ91D Substrate

2011 ◽  
Vol 239-242 ◽  
pp. 1915-1918
Author(s):  
Guan Jun Liu ◽  
Zhou Yu ◽  
Li Jie Ma ◽  
Jun Cao
Keyword(s):  
Electron Microscope ◽  
Magnesium Alloy ◽  
Orthogonal Test ◽  
Bending Test ◽  
Az91d Magnesium Alloy ◽  
Plating Solution ◽  
Electroless Ni ◽  
Good Coating ◽  
Alternating Bending ◽  
Scanning Electron

In order to improve and simplify the process of electroless Ni-P plating on AZ91D magnesium alloy substrate, pretreatment process and deposite time were optimized by orthogonal test, the plating morphology were analysed using Quanta 200 type scanning electron microscope. The bond between the plating and aluminum substrate were evaluated using method of water quenching and alternating bending test. The results show that good coating can be obtained on AZ91D substrate under the condition of the acid electroless Ni-P plating solution with pickling time of 40-50s, activated time of 10 min. And the good bond between the coating and AZ91D substrate was obtained.

Optimizing of Pretreatment Process of Electroless Ni-P Plating on Aluminum Substrate

2011 ◽  
Vol 239-242 ◽  
pp. 860-863
Author(s):  
Guan Jun Liu ◽  
Zhou Yu ◽  
Jun Cao
Keyword(s):  
Electron Microscope ◽  
Sulfuric Acid ◽  
Orthogonal Test ◽  
Aluminum Substrate ◽  
Bending Test ◽  
Plating Solution ◽  
Electroless Ni ◽  
Good Coating ◽  
Alternating Bending ◽  
Scanning Electron

In order to improve and simplify the process of electroless Ni-P plating on aluminum substrate, a activated solution and process were optimized by orthogonal test, the plating morphology were analysed using Quanta 200 type scanning electron microscope. The bond between the plating and aluminum substrate were evaluated using method of water quenching and alternating bending test. The results show that good coating can be obtained on aluminum substrate under the normal condition of the acid electroless Ni-P plating solution with sulfuric acid of 120g/L and nitric acid of 10-15g/L as activated solution and activated time of 20 min. And the good bond between the plating and aluminum substrate was obtained.

Influence of pH on Electroless Ni-P-γAl2O3 Composite Plating on AZ91D Magnesium Alloy by Ultrasonic Wave

2014 ◽  
Vol 665 ◽  
pp. 95-98 ◽  
Author(s):  
Yong Zhe Fan ◽  
Jin Qiu ◽  
Rui Na Ma
Keyword(s):  
Electron Microscopy ◽  
Magnesium Alloy ◽  
Ultrasonic Wave ◽  
Ph Value ◽  
Deposition Rates ◽  
Az91d Magnesium Alloy ◽  
Composite Plating ◽  
Electroless Ni ◽  
Influence Of Ph ◽  
Scanning Electron

A dense electroless plating was obtained through the process of chemical Ni-P-γAl2O3 composite plating by ultrasonic wave. The influence of pH on deposition rate, microstructure, coating thickness and microhardness of the composite plating was studied. The deposition rates of the coating is the fastest at pH value of 7,which is 17.9×10-5g/cm2/min.The microstructure of the Ni-P-γAl2O3 coatings were analyzed by scanning electron microscopy (SEM). The results indicate that the influence of pH value on magnesium alloy is very large.And the composite coating obtained at pH value of 7 possesses optimal integrated properties, which shows uniform and compact. The plating obtained at pH value of 7 is the thicknest.

SiC Particles Concentration Dependent the Properties of Electroless Ni-P-SiC Coatings

2012 ◽  
Vol 457-458 ◽  
pp. 146-149
Author(s):  
Yan Hai Cheng ◽  
Shi Ju Zhang ◽  
Yu Xing Peng ◽  
Fang Fang Xing ◽  
Jie Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Concentration ◽  
Composite Coatings ◽  
Sic Particles ◽  
Plating Solution ◽  
Electroless Ni ◽  
Sic Coatings ◽  
Scanning Electron ◽  
Sic Particle

In this study, Ni-P-SiC composite coatings were prepared by adding different amount of SiC particles into electroless Ni-P plating solution. The effects of SiC particles concentration in solution on depositing rate and composition of the coatings were investigated. The different SiC contents in coatings could be obtained by adjusting the amount of SiC particle concentration in electroless plating solution. Scanning electron microscopy (SEM) results indicate that SiC particles are dispersed in the composite coating and Ni-P alloy is mainly as a bond metal envelope with SiC particles. At the same time, the microhardness became increased and the wear resistance improved with the increasing of SiC content.

Electroless Ni–P deposition plus zinc phosphate coating on AZ91D magnesium alloy

2006 ◽  
Vol 200 (20-21) ◽  
pp. 5956-5962 ◽  
Author(s):  
J.S. Lian ◽  
G.Y. Li ◽  
L.Y. Niu ◽  
C.D. Gu ◽  
Z.H. Jiang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Zinc Phosphate ◽  
Phosphate Coating ◽  
Az91d Magnesium Alloy ◽  
Electroless Ni

Synthesis and Evaluation of Benzohydrazide Derivative as a Corrosion Protector for Magnesium Alloy in 3%Nacl

2021 ◽  
Author(s):  
RAJA KALIYAPERUMAL ◽  
T.KASILINGAM
Keyword(s):  
Weight Loss ◽  
Electron Microscope ◽  
Magnesium Alloy ◽  
Scanning Electron Microscope ◽  
Alkaline Medium ◽  
Energy Dispersive ◽  
Cathodic Process ◽  
X Ray ◽  
Nyquist Plots ◽  
Scanning Electron

Abstract Inhibition action of 4-Chloro-N(3,4,5-trimethoxybenzilidene) benzohydrazide on the corrosion of magnesium alloy in alkaline medium was investigated by weight-loss technique, Nyquist spectra, Tafel plot, scanning electron microscope and energy dispersive x-ray analysis. Tafel curves of magnesium alloy showed both anodic and cathodic process suppressed. Nyquist plots, scanning electron microscope and energy dispersive x-ray analysis studies provide the confirmatory evidence for the protection of magnesium alloy by the studied inhibitor.

A Novel Electroless Ni-P Deposition on AZ91D Magnesium Alloy

2010 ◽  
Vol 154-155 ◽  
pp. 1330-1335
Author(s):  
Li Ping Wu ◽  
Zhong Dong Yang ◽  
Jing Jing Zhao ◽  
Yong Ping Xie
Keyword(s):  
Magnesium Alloy ◽  
Electrochemical Impedance ◽  
Electroless Nickel ◽  
Deposition Process ◽  
Chemical Compositions ◽  
Good Adhesion ◽  
Plating Bath ◽  
Az91d Magnesium Alloy ◽  
Structure Morphology ◽  
Electroless Ni

Currently, most of electroless nickel phosphorus plating on magnesium alloys has following disadvantages. First, it has been suffering from corrosion issues caused by acidic electroless bath. Second, in order to increase the strength of Ni-P coatings to the Mg substrate, the pretreatments for electroless Ni-P employ hydrofluoric acid (HF) and hexavalent chromium (Cr6+) which can cause pollution and health problems . In this paper, we developed HF-free and alkaline electroless Ni-P deposition process on AZ91D magnesium alloy which avoids the use of SO42- and Cl- ions in the electroless plating bath, thus leading to good adhesion and corrosion resistance of electroless Ni-P coating on magnesium alloy. XRD, SEM, EDS techniques were used to study the structure, morphology, and chemical compositions of the conversion coating and Ni-P coating, respectively. Polarization measurements indicated that the corrosion rate of Ni-P coated Mg was six times lower than that of bare Mg. Electrochemical impedance spectroscopy (EIS) also showed that the Ni-P coating could effectively protect Mg alloy from corrosion.

Bonding of AZ91D Mg Alloy and Al Metal with Mg-Al Eutectic Alloy and its Application in Al Coating on AZ91D Mg Alloy

2009 ◽  
Vol 610-613 ◽  
pp. 866-869
Author(s):  
X.R. Li ◽  
Wei Liang ◽  
Xing Guo Zhao ◽  
L.P. Bian
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Eutectic Alloy ◽  
Engineering Application ◽  
Mg Alloy ◽  
Bending Test ◽  
Reactive Diffusion ◽  
Alloy Plate ◽  
Az91d Magnesium Alloy ◽  
Diffusion Layers

AZ91D magnesium alloy and Al metal were bonded successfully at 450 oC with load of 25 or 31 MPa by using Mg-Al eutectic alloy as the solder in atmosphere. The microstructure of the AZ91D/Al joints was characterized by SEM equipped with EDS, and the bond strength was measured through three-point bending test. It was revealed that reactive diffusion occurred obviously at the jointing part. The diffusion layers are composed of α-Mg + β-Mg17Al12, β-Mg17Al12, γ-Mg2Al3 and α-Al. The average bend strength of AZ91D/Al joints is 24 MPa with maximum value 28 MPa. To demonstrate the potential engineering application of this technology, AZ91D magnesium alloy plate was coated with Al foil and its corrosion resistance was tested. Electrochemical test results showed that the corrosion resistance of Al coated AZ91D magnesium alloy plate was greatly improved compared with the uncoated one.

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