scholarly journals Mechanically Alloyed CoCrFeNiMo0.85 High-Entropy Alloy for Corrosion Resistance Coatings

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3802
Author(s):  
Laura Elena Geambazu ◽  
Cosmin Mihai Cotruţ ◽  
Florin Miculescu ◽  
Ioana Csaki
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Stainless Steel Substrate ◽  
Bulk Material ◽  
Steel Substrate ◽  
Substrate Surface ◽  
Resistance Testing ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
High Entropy

High-entropy alloys could provide a solution for corrosion resistance due to their impressive properties. Solid-state processing of high purity Co, Cr, Fe, Ni and Mo metallic powders and consolidation resulted in a bulk material that was further machined into electro spark deposition electrodes. After the stainless steel substrate surface preparation, thin successive layers of the high-entropy alloy were deposited and Pull-Off testing was performed on the newly obtained coating, for a better understanding of the adhesion efficiency of this technique. Good adhesion of the coating to the substrate was proved by the test and no cracks or exfoliations were present. Corrosion resistance testing was performed in a liquid solution of 3.5 wt.% NaCl for 6 hours at room temperature and the results obtained validated our hypothesis that CoCrFeNiMo0.85 high-entropy alloys could provide corrosion resistance when coating a stainless steel substrate.

Plasma Printing of Micronozzles With Complex Shaped Outlets Into Stainless Steel Sheets

2019 ◽  
Vol 7 (3) ◽  
Author(s):  
Tatsuhiko Aizawa ◽  
Kenji Wasa
Keyword(s):  
Stainless Steel ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Substrate Surface ◽  
Maskless Lithography ◽  
Two Dimensional ◽  
Nitrogen Diffusion ◽  
High Nitrogen ◽  
Steel Sheets ◽  
Inner Diameter

Abstract The plasma printing was developed as a means to fabricate the micronozzle chip with the inner diameter less than 50 μm. The initial two-dimensional micropattern was printed onto the stainless steel substrate surface by the maskless lithography. These printed micropatterns were utilized as a mask to make selective nitriding into the unprinted surface. After removal of printed pattern, the un-nitrided surfaces were chemically etched to leave the nitrided microtexture as a micronozzle chip. High nitrogen supersaturation as well as selective nitrogen diffusion had influence on the spatial resolution in this plasma printing in addition to the digitizing error in the maskless lithography.

scholarly journals Effect of Substrate Surface Roughening on the Capacitance and Cycling Stability of Ni(OH)2 Nanoarray Films

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Adulphan Pimsawat ◽  
Apishok Tangtrakarn ◽  
Nutsupa Pimsawat ◽  
Sujittra Daengsakul
Keyword(s):  
Stainless Steel ◽  
Cyclic Voltammetry ◽  
Specific Capacitance ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Substrate Surface ◽  
Surface Roughening ◽  
Film Stability ◽  
Substrate Roughening ◽  
Charge Discharge

AbstractThe effect of substrate surface roughening on the capacitance of Ni(OH)2/NiOOH nanowall array samples produced via chemical bath deposition for 2, 4, 6, 24 and 48 h on an as-received stainless steel substrate and the same substrate after sandblasting has been investigated. Symmetric cells were subjected to 120,000 charge-discharge cycles to access changes in their capacitance. Specific capacitances were derived from cyclic voltammetry and charge-discharge cycling under a three electrode setup. Substrate roughening significantly increases the capacitance of symmetric cells and film stability since film exfoliation does not occur to the same degree as on the as-received substrate. Interestingly, films deposited on a roughened substrate for 6, 24 and 48 h also exhibit self-recovery of capacitance, which could be related to an electrodissolution-electrodeposition effect. With the use of a roughened substrate, the thinnest film gives the highest specific capacitance, 1456 F g−1, whilst the thickest one shows the highest areal capacitance, 235 mF cm−2, after 20,000 cycles. These results reveal the promise of surface roughening toward increasing the capacitance and stability of Ni(OH)2/NiOOH films.

The Effect of Substrate Preheating and Surface Organic Covering on Splat Formation

1998 ◽  
Author(s):  
C.J. Li ◽  
J.-L. Li ◽  
W.-B. Wang
Keyword(s):  
Stainless Steel ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Substrate Surface ◽  
Thermal Spraying ◽  
Splat Morphology ◽  
Organic Substances ◽  
Splat Formation ◽  
Molten Droplet ◽  
Preheating Temperature

Abstract The splashing usually occurs when a droplet impact on a substrate surface during thermal spraying, which results in the formation of splat with irregularly complicated morphology. In present study splats are formed on polished stainless steel substrate surface covered with different organic substances with different boiling points by plasma spraying under different preheating temperature of substrate in order to clarify the factors which control the splashing during droplet flattening in thermal spray process. The droplet materials used are aluminum, nickel, copper, Ah03 and molybdenum. Three kinds of organic substances used are xylene, glycol and glycerol which are brushed on the surface of substrate before spraying. It is found that when the preheating temperature exceeds 50°C over the boiling point of organic substance brushed on substrate surface the regular disk type splats are formed in the case that no substrate melting occurs by molten droplet. When the flattening of droplet causes the melting of substrate such as the combination of Mo droplet with stainless steel substrate, the preheating of substrate has no influence on splat morphology. The evaporated gas induced splashing and substrate surface melting induced splashing models are proposed to interpret the formation of the annulus-ringed splat

Biomimetic fabrication of robust self-assembly superhydrophobic surfaces with corrosion resistance properties on stainless steel substrate

RSC Advances ◽  
2016 ◽  
Vol 6 (50) ◽  
pp. 43937-43949 ◽  
Author(s):  
Tianchi Chen ◽  
Hongtao Liu ◽  
Haifeng Yang ◽  
Wei Yan ◽  
Wei Zhu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Self Assembly ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Superhydrophobic Surfaces ◽  
Nanosecond Laser ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Biomimetic Fabrication

The anti-corrosion and robust superhydrophobic stainless surface is obtained by nanosecond laser direct writing.

scholarly journals Microstructure and Corrosion Behavior of (CoCrFeNi)95Nb5 High-Entropy Alloy Coating Fabricated by Plasma Spraying

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 694 ◽  
Author(s):  
Wenrui Wang ◽  
Wu Qi ◽  
Lu Xie ◽  
Xiao Yang ◽  
Jiangtao Li ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Plasma Spraying ◽  
Steel Substrate ◽  
Alloy Coating ◽  
High Entropy Alloy ◽  
Pitting Potential ◽  
Q235 Steel ◽  
High Entropy ◽  
Passivation Film ◽  
Elemental Segregation

In this paper, the (CoCrFeNi)95Nb5 high-entropy alloy (HEA) coating with a thickness of 500 μm on Q235 steel substrate was fabricated by plasma spraying. The microscopic results showed that a new Laves phase is formed in the (CoCrFeNi)95Nb5 HEA coating compared to the HEA powder, and elemental segregation occurs between the dendrites and the interdendrites of the coating, while the interdendritic phase enriches with the Cr and Nb. The phase composition change and elemental segregation behavior were mainly due to the faster cooling rate of the plasma spraying technique. At the junction of the coating and the substrate, the HEA coating bonded well to the substrate; in addition, the width of transition zone was merely 2 μm. The microhardness of the (CoCrFeNi)95Nb5 HEA coating was 321 HV0.5, which is significantly higher than that of the substrate. In terms of corrosion resistance, the (CoCrFeNi)95Nb5 HEA coating has good corrosion resistance in NaCl solution. Although the corrosion form was pitting corrosion, the pitting potential of the (CoCrFeNi)95Nb5 HEA coating was significantly higher than that of other coatings, which was mainly because of the dense passivation film formed by Cr and Nb on the surface of the coating. Once the passivation film was destroyed by Cl−, the selective corrosion occurred on the surface of the (CoCrFeNi)95Nb5 HEA coating. In summary, the (CoCrFeNi)95Nb5 HEA coating prepared by plasma spraying technology can significantly improve the corrosion resistance and mechanical properties of the Q235 steel substrate.

scholarly journals Corrosion Behavior of FeB-30 wt.% Al0.25FeNiCoCr Cermet Coating in Liquid Zinc

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 622
Author(s):  
Xiaolong Xie ◽  
Bingbing Yin ◽  
Fucheng Yin ◽  
Xuemei Ouyang
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
316L Stainless Steel ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Liquid Zinc ◽  
Cermet Coating ◽  
Abrasion Wear ◽  
Better Than

The corrosion of galvanizing equipment parts by liquid zinc is an urgent problem that needs solving. In this work, FeB-30 wt.% Al0.25FeNiCoCr cermet coating was deposited on the surface of 316L stainless steel by AC-HVAF to protect galvanizing equipment parts from corrosion by liquid zinc. The microstructures and phase compositions of powders and the coating were determined by SEM, EDS, and XRD in detail. Additionally, the microhardness, fracture toughness, abrasion wear resistance, and corrosion resistance of the coating to liquid zinc were also studied. The results indicate that the abrasion wear resistance and corrosion resistance of the coating are much better than that of the 316L stainless steel substrate. The failure of the coating in liquid zinc is mainly due to the penetration of liquid zinc into macro-cracks, which causes the coating to peel off.

scholarly journals The Effect of Powder Composition on the Microstructure and Corrosion Resistance of Laser Cladding 60NiTi Alloy Coatings on SS 316L

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1104
Author(s):  
Zexu Du ◽  
Zhengfei Hu ◽  
Yuqiang Feng ◽  
Fan Mo
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Laser Cladding ◽  
316L Stainless Steel ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Eutectic Structure ◽  
Nacl Solution ◽  
Powder Composition ◽  
Ni Powder

Two kinds of 60NiTi powders were prepared by pure Ni mixed with Ti powders, and 55NiTi alloy powder with pure Ni powder and both the powders were fully mixed by alcohol ball milling. Two kinds of coatings (denoted as 60Ni-40Ti and 55NiTi-5Ni) were prepared on a 316L stainless steel substrate by laser cladding. The microstructure, microhardness and electrochemical behavior of the prepared coatings were investigated extensively. The results show that 55NiTi-5Ni has a typical dendritic eutectic structure, but 60Ni-40Ti tends to form a eutectic network structure. The main phases in both coatings are (Ni, Fe)Ti and (Ni, Fe)3Ti; however, the (Ni, Fe)Ti phase is dominant in 55NiTi-5Ni, but the (Ni, Fe)3Ti phase is more prevalent in 60Ni-40Ti. The microhardness was significantly improved with the 316L stainless steel substrate, and the microhardness of 55NiTi-5Ni is slightly higher than 60Ni-40Ti. The corrosion resistance of the two coatings in 3.5 wt% NaCl solution also leads to significant improvements compared with the substrate, and the corrosion resistance of 55NiTi-5Ni was also increased. These different behaviors and characteristics might be related to the different microstructures. Uniform and fine eutectic structure in 55NiTi-5Ni coating lead to better performance, which is also conducive to the formation of the dense oxide film to improve corrosion resistance.

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