Influence of Substrate Temperature on Microcracks Formation in Plasma-Sprayed Yttria-Stabilized Zirconia Splats

2008 ◽  
Vol 373-374 ◽  
pp. 69-72 ◽  
Author(s):  
Ya Zhe Xing ◽  
Yong Li ◽  
Chang Jiu Li ◽  
Cheng Xin Li ◽  
Guan Jun Yang
Keyword(s):  
Substrate Temperature ◽  
Thermal Stresses ◽  
Initial Temperature ◽  
Crack Density ◽  
Crack Spacing ◽  
Stabilized Zirconia ◽  
Substrate Adhesion ◽  
Molten Droplets ◽  
Influence Of Substrate ◽  
Plasma Sprayed

YSZ molten droplets created by plasma spraying were deposited on the YSZ substrate preheated to different temperature from 75oC to 1000oC. The results showed that there is little change in crack spacing when substrate temperature is less than about 740oC, and a significant increase in crack spacing from 3.54 μm at 740oC to 10.91 μm at 1000oC was observed. A simple qualitative model was proposed on the basis of the origin of thermal stresses to explain the influence of substrate initial temperature on crack density characterized by crack spacing. The analysis indicates that the results can be ascribed to the changes in tensile stress and splat/substrate adhesion resulting from changes of substrate initial temperature.

Analysis on Rapid Cooling and Epitaxial Solidification of a Plasma-Sprayed Yttria Stabilized Zirconia Splat on a High-Temperature Substrate

2007 ◽  
Author(s):  
Ya-Zhe Xing ◽  
Chang-Jiu Li ◽  
Jiang-Hao Qiao ◽  
Guo-Xiang Wang
Keyword(s):  
Substrate Temperature ◽  
Epitaxial Growth ◽  
Initial Temperature ◽  
Substrate Surface ◽  
Yttria Stabilized Zirconia ◽  
Transfer Model ◽  
Stabilized Zirconia ◽  
Model Calculations ◽  
Equilibrium Solidification ◽  
Plasma Sprayed

In many applications, it will be beneficial if the plasma-sprayed Yttria stabilized zirconia (YSZ) coatings exhibit epitaxial growth. Early experiments in plasma spray have shown that a high initial substrate temperature may help develop epitaxial growth from the previous deposited splats. This paper has performed an experiment to demonstrate the possibility of epitaxial growth in plasma-sprayed YSZ coatings at high substrate temperatures. A quantitative analysis of splat cooling and rapid solidification of the YSZ splat is then presented. The analysis is based on a one-dimension heat transfer model of a thin liquid YSZ layer in contact with an YSZ substrate at fairly high initial temperature. The model calculations indicate that equilibrium solidification may take place on the YSZ substrate but with a solidification temperature that is much higher than the YSZ substrate temperature. Such equilibrium solidification requires nucleation of new crystalline YSZ and therefore only leads to non-epitaxial growth. Epitaxial growth, on the other hand, requires a large melt undercooling so the YSZ crystalline can grow directly from the substrate surface, which is at a much lower temperature than the equilibrium melting point. The effect of the substrate initial temperature on the development of melt undercooling within the splat is investigated in detail. Some interesting observations have been made which may explain the physics of epitaxial growth in YSZ coatings.

Influence of Substrate Temperature and Hydrothermal Treatment on the Phase Composition of Plasma-Sprayed Phosphate Coatings

2021 ◽  
Vol 57 (6) ◽  
pp. 598-602
Author(s):  
V. I. Kalita ◽  
D. I. Komlev ◽  
A. A. Radyuk ◽  
V. S. Komlev ◽  
V. F. Shamrai ◽  
...  
Keyword(s):  
Phase Composition ◽  
Substrate Temperature ◽  
Hydrothermal Treatment ◽  
Phosphate Coatings ◽  
Influence Of Substrate ◽  
Plasma Sprayed

scholarly journals The Morphology Analysis of Plasma-Sprayed Cast Iron Splats at Different Substrate Temperatures via Fractal Dimension and Circularity Methods

2019 ◽  
Vol 38 (2019) ◽  
pp. 692-698
Author(s):  
Qiulan Wei ◽  
Li He ◽  
Zhang Liu ◽  
Xiao Feng ◽  
Ya-Zhe Xing
Keyword(s):  
Fractal Dimension ◽  
Cast Iron ◽  
Substrate Temperature ◽  
Solidification Rate ◽  
Molten Droplet ◽  
Characterization Methods ◽  
Different Temperatures ◽  
Molten Droplets ◽  
The Difference ◽  
Plasma Sprayed

AbstractPlasma-sprayed cast iron splats were deposited onto polished aluminum substrates preheated to different temperatures ranging from 25°C to 250°C. The morphology of single splat was observed by a field emission scanning electron microscope. Quantitative characterization methods, including fractal dimension (FD) and circularity analyses of the splat profile, were employed to identify the difference in morphology of the splats with the change of the substrate temperature. The results showed that the substrate temperature has a significant effect on the spreading of molten droplets and the morphology of resultant splats through changing the solidification rate of the droplets. With the increment of substrate temperature, the homogeneous and sufficient spreading of the droplets resulted from low solidification rate reduces the splashing of the droplets. In addition, the evaporation of adsorbed moisture on the substrate improves the wettability between the spreading droplet and the substrate, then benefits the homogeneous spreading of the molten droplet. As a result, a distinct decline in the FD value was observed. It was also suggested that the FD analysis could be used to characterize the morphology of the splat more effectively while the circularity method was heavily dependent on the area of the splat.

The influence of substrate temperature and spraying distance on the properties of plasma sprayed tungsten and steel coatings deposited in a shrouding chamber

2017 ◽  
Vol 318 ◽  
pp. 217-223 ◽  
Author(s):  
Jiří Matějíček ◽  
Monika Vilémová ◽  
Barbara Nevrlá ◽  
Lenka Kocmanová ◽  
Jakub Veverka ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Influence Of Substrate ◽  
Plasma Sprayed

Influence of Substrate Condictions on Thermal-Shocking Property of Sm2Zr2O7/NiCoCrAlY Graded Thermal Barrier Coatings

2012 ◽  
Vol 557-559 ◽  
pp. 1764-1767
Author(s):  
Jian Ping Ji ◽  
Ren Xi Hu ◽  
Shu Hua Li
Keyword(s):  
Finite Element Method ◽  
Thermal Barrier Coatings ◽  
Thermal Stresses ◽  
Thermal Barrier ◽  
Substrate Thickness ◽  
Barrier Coatings ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Influence Of Substrate ◽  
Plasma Sprayed

The effect of substrate conditions, including material type, thickness and radius on thermal shocking properties of plasma sprayed Sm2Zr2O7/NiCoCrAlY functional graded thermal barrier coatings were analyzed by ANSYS—a finite element method software. Results show that thermal stresse in coatings increase with increasing of thermal expansion coefficients of substrates. The effect of substrate thickness can be ignored when it is greater than 20mm. Thermal stresses increase with radius increasing, however, they are almost not effected when substrate radius is over 18mm.

Influence of substrate temperature on nitridation of (001) GaAs using RF-radical source

2009 ◽  
Vol 311 (10) ◽  
pp. 2992-2995 ◽  
Author(s):  
Shigeya Naritsuka ◽  
Midori Mori ◽  
Yoshitaka Takeuchi ◽  
Takahiro Maruyama
Keyword(s):  
Substrate Temperature ◽  
Influence Of Substrate
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