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

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.

Investigation of Metal Droplet Flattening Behavior after Impacting onto Stainless Steel Substrate

2009 ◽  
Vol 628-629 ◽  
pp. 703-708 ◽  
Author(s):  
Hao Ping Zeng ◽  
Liang Rong Zhu ◽  
Y.Q. Gao ◽  
Wen Ji Xu ◽  
L. Yang ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Stainless Steel ◽  
Impact Velocity ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Metal Droplet ◽  
Spray Forming ◽  
Molten Droplet ◽  
Plasma Spray Forming ◽  
The Impact

During plasma spray forming, the forming quality is directly influenced by the flattening behavior of the droplet impacted onto the substrate, which is determined by the flattening configuration and solidification state of the droplet. In this study, according to the rule of Reynolds number and Peclet number, the flattening behavior of big-size molten droplet impacted onto the substrate with low-speed were experimentally simulated during flattening. The droplets of Sn30Pb70, Zn and ZA12 impacting onto the stainless steel substrate with different velocity were investigated. Splashing degree was introduced to evaluate the flattening profiles of the splats. The relationships between the splashing degree and the impact velocity, Reynolds number and Weber number of the droplet were established. Experimental results show that the flattening and diffusion are impeded by the dynamic viscosity and surface tension of the droplets, and the impeding effects are more remarkable when the impact velocity is lower. The research has a significant ap

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.

Effect of Substrate Temperature on Microstructural Characteristics of Thermal Sprayed Superalloys

2011 ◽  
Vol 495 ◽  
pp. 13-17
Author(s):  
Fardad Azarmi ◽  
Ghodrat Karami
Keyword(s):  
Substrate Temperature ◽  
Plasma Spraying ◽  
Steel Substrate ◽  
Substrate Surface ◽  
Thermal Spraying ◽  
Air Plasma ◽  
Microstructural Characteristics ◽  
Splat Formation ◽  
Vacuum Plasma Spraying ◽  
Porosity Level

Recently, there has been a huge interest in application of thermal spraying processes to apply a protective layer on the surface of engineering components. Thermal spraying as a near net shape forming technique has also found applications in manufacturing of advanced engineering components. Spraying methods such as High Velocity Oxygen Fuel (HVOF), Vacuum Plasma Spraying (VPS), and Air Plasma Spraying (APS) are among the most commonly used deposition techniques. Coatings are built up from impact of molten particles on the substrate surface and their flattening and solidification (splat formation). Deposition of millions of individual splats connected to each other at different layers will result in a lamellae type structure. This is a typical example of an anisotropic microstructure. The microstructural features such as porosity, oxide layers define the physical and mechanical properties of coating material. This study investigates the influence of substrate temperature on microstructural characteristics of APS deposited superalloy 625 on steel substrate. The coatings were deposited on substrates at different temperatures. The porosity level was measured using prosimetry. Both image analysis technique and Electron Probe Microanalysis (EPMA) was used to measure the amount of oxide phase. The results indicated that lower substrate temperature results in lower oxide in microstructure. There has been no significant change in porosity level due to substrate temperature.

Vibration based Energy Harvester Employing ZnO Film on the Stainless Steel Substrate

2013 ◽  
Vol 133 (4) ◽  
pp. 126-127 ◽  
Author(s):  
Shota Hosokawa ◽  
Motoaki Hara ◽  
Hiroyuki Oguchi ◽  
Hiroki Kuwano
Keyword(s):  
Stainless Steel ◽  
Energy Harvester ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Zno Film
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