Structure and Anti-Corrosion of Tri-Layer Ni-P Amorphous Alloy Coating Prepared in the Same Bath

2007 ◽  
Vol 546-549 ◽  
pp. 1805-1808
Author(s):  
Li Qun Zhu ◽  
Yan Bin Du ◽  
Zhen Xue ◽  
Ying Xu Li
Keyword(s):  
Corrosion Resistance ◽  
Alloy Coating ◽  
Amorphous Coating ◽  
Nacl Solution ◽  
Excellent Performance ◽  
Electrochemical Protection ◽  
Heat Treated ◽  
Before And After ◽  
Layer Coating

A tri-layer amorphous Ni-P alloy coating was prepared in the same bath by changing the temperatures and currents, followed by heat treament. We studied the behavior of corrosion-resistance of the tri-layer coating before and after heat-treatment at 360°C for different time in the 5% NaCl solution. The result showed that: the tri-layer amorphous Ni-P coating has the excellent performance of anti-corrosion compare with single electroless or electrodeposited Ni-P amorphous coating. The performance of anti-corrosion of the coating was improved by controlling the coating’s structure and the role of electrochemical protection. After being heat-treated at 360°C for 1 hour ,the coating’s structure changed from amorphous to crystalloid and the corrosion resistance of the heat-treated coatings was higher than as-plated tri-layer Ni-P coating.

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.

Characterization of Ni-P and Ni-P-Al2O3 Heat Treated Layers

2017 ◽  
Vol 1143 ◽  
pp. 26-31
Author(s):  
Lucica Balint ◽  
Gina Genoveva Istrate
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
Composite Coatings ◽  
Treatment Temperature ◽  
Initial State ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Before And After

Research has shown the relationship among hardness, usage and corrosion resistance Ni-P-Al2O3 composite coatings on steel support heat treated. The electroless strips were heat treated at 200°C, 300°C, 400°C, 500°C and 600°C. Further studies on corrosion, hardness and usage revealed changes in properties, compared to the initial state, both on the strips coated with Ni-P and the ones coated with Ni-P-Al2O3 composite. The samples have been studied before and after the heat treatment via Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Analysis (EDX) and X-Ray Diffraction (XRD). The results show that untreated Ni-P layers exhibit strong corrosion resistance, while hardness and usage increase with heat treatment temperature, with a peak at 400 °C. Using suspended particles co-deposition, led to new types of layers, some with excellent hardness and usage properties. Corrosion resistance increase with heat treatment. Coating layers can be adjusted to the desired characteristics, by selecting proper parameters for the expected specific results.

Corrosion Studies of Sintered Cobalt-Based Alloys in Sodium Chloride

2021 ◽  
Vol 107 ◽  
pp. 144-148
Author(s):  
Feyisayo Victoria Adams ◽  
Reneilwe Agrieneth Moloto ◽  
Samuel Olukayode Akinwamide ◽  
Peter Apata Olubambi
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Techniques ◽  
Nacl Solution ◽  
Medical Field ◽  
Sem Images ◽  
Electrochemical Tests ◽  
Cr Content ◽  
Corrosion Studies ◽  
Before And After ◽  
Ti Addition

Cobalt-based alloys have recently gained so much attention in the medical field due to their improved mechanical properties such as wear resistance and high thermal stability. However, limitations in the area of corrosion has posed a great challenge, leading to further studies being carried out on the corrosion resistance of these alloys. In this study, an investigation on the corrosion resistance of Co-Cr-Mo based alloys in 0.9 % NaCl solution was carried at 37 oC and pH of 7.4 using potentiodynamic polarization and chronopotentiometry electrochemical techniques. The surface analysis of the alloys before and after corrosion test was done using scanning electron microscope (SEM). The results obtained from the electrochemical tests showed sample without titanium (Ti) addition to be more resistance to corrosion in the salt solution compared to those containing Ti. It was observed that a decrease in Cr content in the alloys resulted in an increase in corrosion rate from 0.7868 to 1.3805 mpy. The SEM images confirmed the presence of Cr, Co and Mo in the alloys.

scholarly journals Effects of Heat Treatment on the Corrosion Behavior of ASTM A-36 Steel

2020 ◽  
Vol 10 (1) ◽  
pp. 5320-5324
Author(s):  
I. Alenezi
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Weight Loss Measurement ◽  
Acidic Media ◽  
Loss Measurement ◽  
Corrosion Rates ◽  
Heat Treated ◽  
Before And After ◽  
Quenched Steel ◽  
Steel Hardening

The effects of different tempering temperatures and heat treatment times on the corrosion resistance of rolled ASTM A-36 steel in various concentrations of hydrochloric acid (HCl) and sodium chloride (NaCl) were studied in this work, using the conventional weight loss measurement. Rolled and heat-treated specimens were placed in the acidic media for five days and for seven days in NaCl, respectively, and the corrosion rates were evaluated. The microstructure of steel before and after heat treatment was studied. Corrosion resistance revealed remarkable changes from the effect of tempering after water or oil quenching of steel. Generally, the corrosion rate increases from the effect of steel hardening. Tempering of water-quenched steel at 450Co for one hour highly improves the corrosion resistance of 0.27% carbon steel.

Effect of Sealing Treatment of Modified Aluminum Phosphate Sealing Agent on Corrosion Resistance of Fe-Based Amorphous Coating

2022 ◽  
Vol 905 ◽  
pp. 61-66
Author(s):  
Cheng Fei Li ◽  
Xiao Jun Yang ◽  
Ding Yong He
Keyword(s):  
Corrosion Resistance ◽  
Heat Resistance ◽  
Raw Materials ◽  
Aluminum Phosphate ◽  
Dihydrogen Phosphate ◽  
Amorphous Coating ◽  
Before And After ◽  
Sealing Treatment ◽  
Good Heat Resistance ◽  
Sealing Layer

A modified aluminum phosphate sealing agent was prepared by using aluminum dihydrogen phosphate and silica sol as raw materials, and was used for sealing treatment of iron-based amorphous coating. The phase of sealing agent was analyzed by XRD. SEM and TG-DSC were used to characterize the surface morphology of the coating before and after sealing and the heat resistance of the sealing agent. The corrosion resistance of the sealing coating was evaluated by electrochemical measurements. The results show that the modified aluminum phosphate sealing agent has good heat resistance, and fine and close sealing layer was obtained, thus the corrosion resistance is significantly improved.

Characterization of corrosion resistance of Zn-Ni-W and Zn-Ni-P-W heat-treated coatings

2021 ◽  
Vol 25 (3-4) ◽  
pp. 13-17
Author(s):  
Magdalena Popczyk ◽  
Jolanta Niedbała
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Surface Morphology ◽  
Electrochemical Corrosion ◽  
Nacl Solution ◽  
Heat Treated ◽  
Electrochemical Corrosion Resistance

The paper presents results of research concerning the evaluation of corrosion resistance of heat-treated alloy coatings (Zn-Ni-W/320°C and Zn-Ni-P-W/320°C). The surface morphology and phase composition of the obtained coatings were determined. Electrochemical corrosion resistance was studied in 5% NaCl solution. On the basis of these studies it was found that the corrosion resistance of Zn-Ni-P-W/320°C coating is higher than Zn-Ni-W/320°C coating.

AN APPROXIMATION TO DETERMINE CORROSION AND MECHANICAL BEHAVIOR OF TI-BASED ALLOYS

2020 ◽  
pp. 2150001
Author(s):  
YESIM YILMAZ ◽  
HULYA DEMIROREN
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
High Corrosion Resistance ◽  
Commercially Pure ◽  
Grade 5 ◽  
Heat Treated ◽  
Before And After ◽  
Mechanical Properties And Corrosion ◽  
Cp Ti

Titanium and its alloys used in biomaterial applications are preferrably the cause of high-corrosion resistance properties in addition to having good mechanical properties. Commercially pure Ti (CP-Ti) (Grade 2), Ti6Al4V (Grade 5) and Ti6Al4V-ELI (Grade 23) samples are used as biomaterials exposed to 750°C and 1060°C for 1[Formula: see text]h. The samples were cooled in air after heat treatment at 750°C, the other samples were cooled in water after heat treatment at 1060°C. The free-heat treatment samples are as producted. Microstructures of heat-treated samples and non-made samples by comparison were evaluated before and after corrosion process microstructures and tensile strengths. Test solution is 0.5[Formula: see text]mol H2SO[Formula: see text][Formula: see text]mol HCl mixture. The corrosion resistance of the titanium samples was evaluated. Microstructure images were monitorized on optical and SEM microscopes. In this paper, the effect of heat treatment was determined on the microstructure, mechanical properties and corrosion resistances of the material. As a result, heat treatment is useful on corrosion resistance of alloyed samples.

Corrosion Resistance of Mo-Fe-Ti Alloy for Overpack in Simulating Underground Environment

2010 ◽  
Author(s):  
Toshiyasu Nishimura
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Selective Dissolution ◽  
Immersion Test ◽  
Ti Alloy ◽  
Nacl Solution ◽  
Β Phase ◽  
Heat Treated

In order to examine the application of Mo-Fe-Ti alloy for overpak, the corrosion resistance of heat-treated its alloys was investigated by Electrochemical impedance spectroscopy (EIS), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM) and Energy dispersive X-ray analysis (EDAX). Considering the welding, the sample subjected to solution heat treatment (ST) had a single β phase and samples subjected to aging heat treatment at 600–700°C had a-phase precipitation in b-phase. EIS results showed that the corrosion resistance of the aging heat-treated samples was lower than that of the ST sample, but much higher than that of pure Ti in long term immersion test in 10% NaCl solution of pH 0.5 at 97°C which simulating the crevice solution. Laser micrographs of the aging heat-treated samples indicated that a-phase at the grain boundary and in the grain was selectively corroded and caused selective dissolution in NaCl solution. The results of TEM combined with EDAX analyses showed that there were b-phase matrix composed of 2.7 wt% of Mo and 4.8wt% of Fe, and a-phase composed of 0.7 wt% of Mo and 0.1 wt% of Fe in sample aged at 600°C. Thus, Mo-poor a-phase was selectively dissolved in in 10% NaCl solution of pH 0.5 at 97°C. In a result, the ST sample of only b-phase showed the highest resistance, and aging heat-treated samples containing a-phase (0.7 wt% of Mo) showed higher values than pure Ti in the corrosion test. Addition of Fe did not decrease the resistance of alloy in the case of ST condition. Moreover, as Fe was involved in b-phase with Mo which increased remarkably the corrosion resistance, the addition of Fe did not decrease the corrosion resistance of aging heat-treated Mo-Fe-Ti alloy. Finally, it was concluded that Mo-Fe-Ti alloy had excellent resistance for overpack in simulating underground environment.

scholarly journals Effect of heat treatment on the tribological performance of electroless quaternary nickel alloy

2019 ◽  
Vol 13 (3) ◽  
pp. 5637-5652
Author(s):  
M. Zaimi ◽  
M. N. Azran ◽  
M. S. Kasim ◽  
M. R. M. Kamal ◽  
I. S. Othman ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Wear Behavior ◽  
Steel Substrate ◽  
Alloy Coating ◽  
Xrd Analysis ◽  
Alloy Matrix ◽  
X Ray ◽  
Hardness Tester ◽  
Heat Treated ◽  
Before And After

Heat treatment of nickel-based alloy can increase the alloy’s hardness as well as the wear resistance properties. Nevertheless, the effect of heat treatment on the quaternary Ni alloy coating properties produced from electroless deposition bath is less known due to its composition uniqueness. In this study, Cu and Co are added in the Ni-P alloy matrix using hypophosphite-based Electroless Ni deposition method on mild steel substrate in acidic and alkaline bath. The coatings are then heat treated at 623 K for 3600s. The coatings hardness is measured using microVickers hardness tester and the surface morphology of the coatings are studied using both Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) analysis. X-ray fluorescence (XRF) measurement is used to measure the coatings compositions. The wear behavior of the coatings is also investigated before and after heat treatment using ASTM G-99. The coatings from acidic-based bath produces Ni-Cu-Co-P alloy coating while the alkaline-based bath produces Ni-Co-Cu-P alloy based on XRF analysis. Results show that the hardness increases more than 20% for acidic-based bath and 40% for alkaline-based bath coating. The highest increment is the Ni-Co-Cu-P alloy, from 553.3 HV to 991.3 HV after heat treatment. The grain refinement of the coatings can be observed after heat treatment in SEM observation. This is proved by the XRD measurement results where polycrystalline Ni (111) formation is seen after heat treatment overshadowing the Cu (111) and Co (111) peaks. Ni phosphide species are also formed after the heat treatment. The polycrystalline Ni and the Ni phosphide formation, as well as the existence of Co and Cu in the alloy deposits reduces the wear rate significantly after the heat treatment.

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