Study on Ultrasonic Electroforming Ni-P Coatings on NdFeB Permanent Magnet

2012 ◽  
Vol 535-537 ◽  
pp. 1275-1278
Author(s):  
Li Li ◽  
Xiang Cheng ◽  
Feng Shi Yin
Keyword(s):  
Corrosion Resistance ◽  
Nacl Solution ◽  
Adhesion Test ◽  
Ndfeb Magnet ◽  
Ultrasonic Agitation ◽  
New Process ◽  
Strong Adhesion ◽  
Alloy Deposit ◽  
Ndfeb Permanent Magnet ◽  
Poor Adhesion

In order to improve the corrosion resistance of sintered NdFeB magnet, experiments are done by the new process which involves ultrasonic electroforming Ni–P alloys. The influence of ultrasonic on electroforming Ni–P alloy on NdFeB was studied by using microscope, adhesion test and NaCl solution immersion test.The results showed that the Ni–P alloy deposit on NdFeB is rough and has poor adhesion without ultrasonic agitation; However, the Ni–P alloy deposit on NdFeB with ultrasonic agitation has the following advantages: uniform and smooth deposit grains, strong adhesion and good corrosion resistance.

Investigation of Ultrasonic Electroplating Ni-P Coatings on Nd-Fe-B Permanent Magnet

2011 ◽  
Vol 284-286 ◽  
pp. 980-983
Author(s):  
Fei Fei Wang ◽  
Li Li
Keyword(s):  
Corrosion Resistance ◽  
Permanent Magnet ◽  
Technological Process ◽  
Immersion Test ◽  
Nacl Solution ◽  
Adhesion Test ◽  
Ultrasonic Agitation ◽  
Uniform Microstructure ◽  
Alloy Deposit ◽  
Poor Adhesion

In order to improve the corrosion resistance of Nd-Fe-B, the new technological process is done which involves electroplating Ni–P alloys with ultrasonic. The influence of ultrasonic on electroplating Ni–P alloy on Nd-Fe-B was studied by using microscope, adhesion test and NaCl solution immersion test. The results showed that the Ni–P alloy deposit on Nd-Fe-B is rough and has poor adhesion without ultrasonic agitation; however, the Ni–P alloy deposit on Nd-Fe-B with ultrasonic agitation has more compact and uniform microstructure, smoother morphology. At the same time, the adhesion and corrosion resistance are greatly enhanced.

Research of the Surface Treatment Process of Bonded NdFeB Magnet with Composite Powder Electrostatic Spraying

2018 ◽  
Vol 278 ◽  
pp. 63-71 ◽  
Author(s):  
Kai Ye Xiao ◽  
Hai Xu ◽  
Zhi Wei Guo ◽  
Wen Zheng
Keyword(s):  
Corrosion Resistance ◽  
Surface Treatment ◽  
Surface Coating ◽  
Composite Powder ◽  
Treatment Process ◽  
Ndfeb Magnet ◽  
Treatment Technology ◽  
Electrostatic Spraying ◽  
Strong Adhesion ◽  
Epoxy Paint

Compared with the traditional air spraying technique and electroplate method, the coating defects of bonded NdFeB magnet, such as the workpiece hanging point, the pinhole, the bubble, have been solved by using the composite powder electrostatic spraying as surface treatment technology, along with the EE epoxy paint as primer coating and PU polyurethane paint as surface coating. The coating of this composite powder electrostatic spraying is uniform and compact, and the coating has strong adhesion and corrosion resistance. This paper gives a detailed introduction to the composite powder electrostatic spraying, including the choice of some important parameters and the unique hanging tools of composite powder electrostatic spraying.

Synthesis and Properties of Electroless Ni-P-W/Nano-Al2O3 Composite Coatings Deposited on Sintered NdFeB Permanent Magnet

2011 ◽  
Vol 306-307 ◽  
pp. 901-906 ◽  
Author(s):  
Huan Ming Chen ◽  
Ya Hong Gao ◽  
Qiong Lv ◽  
Dong Yang ◽  
Xin Xin Lin
Keyword(s):  
Corrosion Resistance ◽  
Permanent Magnet ◽  
Composite Coatings ◽  
Alloy Coating ◽  
X Ray Diffraction ◽  
Ndfeb Magnet ◽  
X Ray ◽  
Plating Method ◽  
Ndfeb Permanent Magnet ◽  
Electroless Ni

The Ni-P-W/nano-Al2O3composite coatings were deposited on the surface of sintered NdFeB permanent magnet by electroless plating method. The morphology and the phases of Ni-P-W/nano-Al2O3composite coatings were investigated using scanning electron microscopy and X-ray diffraction respectively. The hardness and the corrosion resistance of the composite coatings were also tested. The results indicated that the composite coatings morphology appears closely nodules morphology, and the microhardness increases with increasing incorporation of Al2O3ratio. Compared with NdFeB magnet and Ni-P-W alloy coatings, the corrosion resistance of the composite coatings was superior to that of the NdFeB magnet and the alloy coating obviously.

Investigation on Properties of Electroless Ni-P-W/Al2O3 Composite Coatings Deposited on Sintered NdFeB Permanent Magnet

2012 ◽  
Vol 476-478 ◽  
pp. 397-401 ◽  
Author(s):  
Dong Yang ◽  
Xin Xin Lin ◽  
Huan Ming Chen ◽  
Ya Hong Gao ◽  
Qiong Lv ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Amorphous Alloy ◽  
Permanent Magnet ◽  
Composite Coatings ◽  
Alloy Coating ◽  
Linear Increase ◽  
X Ray Diffraction ◽  
Ndfeb Magnet ◽  
Plating Method ◽  
Ndfeb Permanent Magnet

The Ni-P-W/Al2O3composite coatings were deposited on the surface of sintered NdFeB permanent magnet by electroless plating method. The morphology and the phases of Ni-P-W/Al2O3composite coatings were investigated using scanning electron microscopy and X-ray diffraction respectively. The hardness and the corrosion resistance of the composite coatings were also tested. The results indicated that the composite coatings morphology appears closely nodules morphology, and the microhardness increases linearly with increasing incorporation of Al2O3ratio. Compared with NdFeB magnet and Ni-P-W amorphous alloy coating, the corrosion resistance of the composite coatings was superior to that of the NdFeB magnet and the amorphous alloy coating obviously. However, for the corrosion resistance of Ni-P-W/Al2O3composite coatings with different Al2O3concentration, there is not a linear increase with the Al2O3concentration increasing. The self-corrosion potential of Ni-P-W/Al2O3composite coatings reaches the highest value while increasing incorporation of Al2O3ratio up to 10 g/L.

Ultrasonic Assisted Electro Deposition and Characterization of Ni–P Alloy onto Sintered NdFeB Magnet

2011 ◽  
Vol 239-242 ◽  
pp. 1649-1652
Author(s):  
Li Li ◽  
Fei Fei Wang ◽  
Zong Wei Niu ◽  
Dong Wang
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Potential Problem ◽  
Corrosion And Wear ◽  
Ndfeb Magnet ◽  
Electro Deposition ◽  
Deposition Surface ◽  
Ultrasonic Assisted ◽  
Ndfeb Permanent Magnet

Sintered NdFeB permanent magnet is widely used in many applications because of its excellent magnetic property. But its poor corrosion resistance has been cited as a potential problem with its use.Nickel phosphorus (Ni–P) alloys systems are very attractive due to their good corrosion and wear resistance behavior. In this paper the ultrasonic effect is used in electro deposition. Experimental results show that the ultrasonic improve the deposition surface quality.

scholarly journals Effects of Yttrium Addition on the Microstructure Evolution and Electrochemical Corrosion of SN-9zn Lead-Free Solders Al-Loy

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2549
Author(s):  
Wenchao Yang ◽  
Jun Mao ◽  
Yueyuan Ma ◽  
Shuyuan Yu ◽  
Hongping He ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Microstructure Evolution ◽  
Electrochemical Corrosion ◽  
Lead Free ◽  
Nacl Solution ◽  
Rich Phase ◽  
Yttrium Addition ◽  
Electrochemical Corrosion Behavior ◽  
Lead Free Solders ◽  
Addition Amount

Electrochemical corrosion behavior of ternary tin-zinc-yttrium (Sn-9Zn-xY) solder alloys were investigated in aerated 3.5 wt.% NaCl solution using potentiodynamic polarization techniques, and the microstructure evolution was obtained by scanning electron microscope (SEM). Eight different compositions of Sn-9Zn-xY (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.20, and 0.30 wt.%) were compared by melting. The experimental results show that when the content of Y reached 0.06 wt.%, the grain size of Zn-rich phase became the smallest and the effect of grain refinement was the best, but there was no significant effect on the melting point. With the increases of Y content, the spreading ratio first increased and then decreased. When the content of Y was 0.06 wt.%, the Sn-9Zn-0.06Y solder alloy had the best wettability on the Cu substrate, which was increased by approximately 20% compared with Sn-9Zn. Besides, the electrochemical corrosion experimental shows that the Y can improve the corrosion resistance of Sn-9Zn system in 3.5 wt.% NaCl solution, and the corrosion resistance of the alloy is better when the amount of Y added is larger within 0.02–0.30 wt.%. Overall considering all performances, the optimal performance can be obtained when the addition amount of Y is 0.06.

scholarly journals Microstructure and Corrosion Properties of La2Zr2O7/NiCoAlY Thermal Barrier Coatings Deposited on Inconel 718 Superalloy by Laser Cladding

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 101
Author(s):  
Kaijin Huang ◽  
Wei Li ◽  
Kai Pan ◽  
Xin Lin ◽  
Aihua Wang
Keyword(s):  
Corrosion Resistance ◽  
Thermal Barrier Coating ◽  
Laser Cladding ◽  
Inconel 718 ◽  
Electrochemical Techniques ◽  
Thermal Barrier ◽  
Nacl Solution ◽  
Corrosion Performance ◽  
Barrier Coating ◽  
Inconel 718 Superalloy

In order to improve the seawater corrosion resistance of Inconel 718 superalloy, a La2Zr2O7/NiCoCrAlY thermal barrier coating corrosion resistant to 3.5 wt.% NaCl aqueous solution was prepared by laser cladding on Inconel 718 superalloy. X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and electrochemical techniques were used to study the microstructure and the corrosion performance of the coating in 3.5 wt.% NaCl solution. The results show that the thermal barrier coating is mainly composed of primary La2Zr2O7 phase and γ + laves/δ phase eutectic structure. The corrosion potential and corrosion current of the coating in 3.5 wt.% NaCl solution are higher and lower than that of the Inconel 718 substrate, respectively, indicating that the corrosion performance of the coating is better than that of the Inconel 718 substrate. The presence of La2Zr2O7 phase in the thermal barrier coating is the main reason for its corrosion resistance to 3.5 wt.% NaCl solution.

scholarly journals Effect of Fluid Flow on the Corrosion Performance of as-Cast and Heat-Treated Nickel Aluminum Bronze Alloy (UNS C95800) in Saline Solution

2021 ◽  
Vol 2 (1) ◽  
pp. 61-77
Author(s):  
Hamid Reza Jafari ◽  
Ali Davoodi ◽  
Saman Hosseinpour
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Flow Rate ◽  
Solution Temperature ◽  
Aluminum Bronze ◽  
Nickel Aluminum ◽  
Nacl Solution ◽  
Flow Conditions ◽  
Heat Treated ◽  
Nickel Aluminum Bronze

In this work, the corrosion behavior and surface reactivity of as-cast and heat-treated nickel aluminum bronze casting alloy (UNS C95800) in 3.5 wt% NaCl solution is investigated under stagnant and flow conditions. Increasing flow rate conditions are simulated using a rotating disk electrode from 0 to 9000 revolutions per minute (rpm). Optical micrographs confirm the decrease in the phase fraction of corrosion-sensitive β phase in the microstructure of C95800 after annealing, which, in turn, enhances the corrosion resistance of the alloy. Electrochemical studies including open circuit potentiometry, potentiodynamic polarization, and electrochemical impedance spectroscopy are performed to assess the effect of flow rate and heat treatment on the corrosion of samples at 25 and 40 °C in 3.5 wt% NaCl solution. For both as-cast and heat-treated samples, increasing the flow rate (i.e., electrode rotating rate) linearly reduces the corrosion resistance, indicating that the metal dissolution rate is significantly affected by hydrodynamic flow. Increasing the solution temperature negatively impacts the corrosion behavior of the as-cast and heat-treated samples at all flow conditions.

scholarly journals Assessment of nickel titanium and beta titanium corrosion resistance behavior in fluoride and chloride environments

2013 ◽  
Vol 83 (5) ◽  
pp. 864-869 ◽  
Author(s):  
Elisa J. Kassab ◽  
José Ponciano Gomes
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Fluoride Concentration ◽  
Nickel Titanium ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Nacl Solution ◽  
Galvanic Coupling ◽  
Beta Titanium

ABSTRACT Objective: To assess the influence of fluoride concentration on the corrosion behavior of nickel titanium (NiTi) superelastic wire and to compare the corrosion resistance of NiTi with that of beta titanium alloy in physiological solution with and without addition of fluoride. Materials and Methods: NiTi corrosion resistance was investigated through electrochemical impedance spectroscopy and anodic polarization in sodium chloride (NaCl 0.15 M) with and without addition of 0.02 M sodium fluoride (NaF), and the results were compared with those associated with beta titanium. The influence of fluoride concentration on NiTi corrosion behavior was assessed in NaCl (0.15 M) with and without 0.02, 0.04, 0.05, 0.07, and 0.12 M NaF solution. Galvanic corrosion between NiTi and beta titanium were investigated. All samples were characterized by scanning electron microscopy. Results: Polarization resistance decreased when NaF concentration was increased, and, depending on NaF concentration, NiTi can suffer localized or generalized corrosion. In NaCl solution with 0.02 M NaF, NiTi suffer localized corrosion, while beta titanium alloys remained passive. Current values near zero were observed by galvanic coupling of NiTi and beta titanium. Conclusions: There is a decrease in NiTi corrosion resistance in the presence of fluoride. The corrosion behavior of NiTi alloy depends on fluoride concentration. When 0.02 and 0.04 M of NaF were added to the NaCl solution, NiTi presented localized corrosion. When NaF concentration increased to 0.05, 0.07, and 0.12 M, the alloy presented general corrosion. NiTi corrosion resistance behavior is lower than that of beta titanium. Galvanic coupling of these alloys does not increase corrosion rates.

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