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.

Sealing Treatment of Plasma Sprayed Cr3C2-NiCr/Al2O3-TiO2 Coating by Aluminum Phosphate Sealant Containing Al2O3 Nanoparticles

2021 ◽  
Author(s):  
Tuan Nguyen Van ◽  
Tuan Anh Nguyen ◽  
Ha Pham Thi ◽  
Ly Pham Thi ◽  
Phuong Nguyen ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Aluminum Phosphate ◽  
Al2o3 Nanoparticles ◽  
Treatment Efficiency ◽  
Typical Structure ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Sealing Treatment ◽  
Sprayed Coatings

Abstract A typical structure of thermal spray coatings consisted of molten particles, semi-molten particles, oxides, pores and cracks. These factors caused the porosity of sprayed coatings, leading to a great influence on the coating properties, especially their wear-corrosion resistance. In this study, a post-spray sealing treatment of Cr3C2-NiCr/Al2O3-TiO2 plasma sprayed coatings was carried out, then their corrosion properties were evaluated, before and after the treatment. For sealing process, aluminum phosphate (APP) containing aluminum oxide (Al2O3) nanoparticles (~10 nm) was used. The permeability of APP into the sprayed coating was analyzed by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The treatment efficiency for porosity and corrosion resistance of sprayed coatings were evaluated by electrochemical measurements, such as the potentiodynamic polarization and electrochemical impedance spectroscopy. In addition, the wear-corrosion resistance of the sealed coating was examined in 3.5 wt.% NaCl circulation solution containing 0.25 wt.% SiO2 particles. The obtained results showed that APP penetrated deeply through the sprayed coating. The incorporation of Al2O3 nanoparticles into APP sealant enhanced the treatment efficiency of porosity for sprayed coating. The effect of the post-treatment on corrosion protection of the sprayed coating has been discussed.

Effect of Aluminum Phosphate Sealing Treatment on Properties of Thick Thermal Barrier Coatings

2000 ◽  
Author(s):  
S. Ahmaniemi ◽  
E. Rajamäki ◽  
P. Vuoristo ◽  
T. Mäntylä
Keyword(s):  
Corrosion Resistance ◽  
Diesel Engine ◽  
Thermal Barrier Coatings ◽  
Hot Corrosion ◽  
Aluminum Phosphate ◽  
Thermal Barrier ◽  
Stabilized Zirconia ◽  
Barrier Coatings ◽  
X Ray ◽  
Sealing Treatment

Abstract Partially stabilized zirconia (8Y2O3-ZrO2) coatings were studied as thick thermal barrier coatings (TTBCs) for diesel engine applications. To improve the hot corrosion resistance of TTBCs the 1 mm thick yttria stabilized zirconia coating was densified with aluminum phosphate based sealant. Combined with better hot corrosion resistance other benefits obtained with sealing treatment are improved adhesion as well as increased mechanical properties of the ceramic layer. Three aluminum phosphate based sealants were investigated with varying viscosity level. Different sealant viscosities were used to optimize the level of sealant penetration into the coating. Sealant penetration and the violence of the reaction were determined by XRD, SEM/EDS and optical microscopy. The hardness profile from bond coat to the surface of the top layer was determined. Coating microstructure and phase structure were characterized by optical microscopy and by X-ray diffraction. Microhardness and porosity were determined. Residual stress states were measured by X-ray based stress analyzer. Bond strength of the coatings was determined with tensile test equipment. To simulate the diesel engine combustion conditions, hot corrosion tests were performed for the sealed TTBCs. Hot corrosion resistance of the coating was tested in isothermal exposure of 60Na2SO4 - 40V2O5 melt for 48 hours at 600 °C.

scholarly journals The Effect of Niobium Addition on Mechanical Properties and Corrosion Resistance of a Medical Grade SS316L

2021 ◽  
Vol 21 (2) ◽  
pp. 178
Author(s):  
I Nyoman Jujur ◽  
Sri Endah Susilowati ◽  
Seto Roseno ◽  
Agus Hadi Santosa Wargadipura
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
316L Stainless Steel ◽  
Raw Materials ◽  
Melting Furnace ◽  
Induction Melting ◽  
Before And After ◽  
Medical Grade

To improve mechanical properties, especially elongation, of as-cast medical grade 316L stainless steel, niobium (Nb) was introduced into the alloys, followed by solution heat treatment. Alloying was performed using a 250 kg air induction melting furnace with duplex raw materials and ferronickel. Heat treatment using a solution at 1040 oC, with a holding time of 45 minutes, and water quenching was used. The sample was tested using hardness and ultimate tensile machines. Corrosion tests with simulated body fluids were carried out using media with similar corrosion conditions to human blood. Microstructure observations were performed optically. The results show that the addition of Nb increases the hardness of medical grade 316L stainless steel by 6% compared to the unalloyed steel, both before and after heat treatment. The addition of Nb increases the tensile strength by 8% compared to non-heat treated steel and increases the elongation before and after heat treatment by 8% and 5%, respectively. However, the corrosion rate of the material with Nb is higher than without the addition of Nb. Nb as a carbide former improves the mechanical properties of medical grade 316L stainless steel but adversely affects its corrosion resistance

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.

DURANICKEL ALLOY 301

Alloy Digest ◽  
1963 ◽  
Vol 12 (6) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Heat Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
High Strength ◽  
Heat Treating ◽  
International Nickel Company ◽  
Temperature Performance

Abstract DURANICKEL Alloy 301 is a wrought, age-hardenable nickel alloy having high strength, high corrosion and heat resistance. It is recommended for springs, diaphrams, bearings, pump and valve parts. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-83. Producer or source: The International Nickel Company Inc..

MC ALLOY

Alloy Digest ◽  
2014 ◽  
Vol 63 (7) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Heat Resistance

Abstract MC Alloy is composed mostly of nickel with 45% chromium. The alloy has outstanding properties for both corrosion and heat resistance. This datasheet provides information on composition. It also includes information on corrosion resistance as well as forming. Filing Code: Ni-713. Producer or source: Hitachi Metals MMC Superalloy Ltd.

AISI TYPE 308

Alloy Digest ◽  
1963 ◽  
Vol 12 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Heat Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Nickel Steel ◽  
Steel Mills ◽  
Aisi Type ◽  
Type 304

Abstract AISI Type 308 is an austenitic chromium nickel steel with corrosion and heat resistance superior to Type 304. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-140. Producer or source: Alloy steel mills and foundries.

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