Splat formation in plasma-spray coating process

2002 ◽  
Vol 74 (3) ◽  
pp. 441-445 ◽  
Author(s):  
Javad Mostaghimi ◽  
Sanjeev Chandra

The paper describes recent developments in modeling formation of plasma-spray coatings. This is a stochastic process in which particle-impact conditions, thermophysical properties, substrate topology, and temperature all play important roles in determining the structure of coating. Specific attention is paid to the simulation of droplet impact and solidification under plasma-spraying conditions. Results of 3-dimensional models show that on a flat surface solidification may cause splashing and break-up of the impacting particle. Undercooling effects result in faster solidification and, thus, smaller extent of spreading. More recent works investigate the effect of surrounding gas on dynamics of impact. It is shown that this could result in entrapment of a bubble under the droplet.

2015 ◽  
Vol 813-814 ◽  
pp. 874-879
Author(s):  
P. Jayanth ◽  
E. Sangeeth Kumar

In this study, the surface of a Piston Ring in the engine is coated with multilayered coating powder using plasma-spray technique, and its surface behavior is subsequently analyzed. The purpose of this study is to analyze the mechanical and thermal effects of surface coating for a Piston Ring during friction. Here specimens with and without coatings were prepared and then microstructure, hardness and corrosion tests were carried out. From the experimental results and Ansys results, it has been found that the coated specimen has improved the properties in improving the diesel engine performance. The results show less deformation and fewer scratches due to wear on the multilayer coated Piston Ring as compared to the uncoated one. The surfaces topography and the structure of the plasma spray coatings is observed on the scanning Electron microscope. The evaluation of the adhesion of coatings is made using the hardness test and also compared using the thermal barrier properties. Taking into account the results of measurements, one can state that the lowest wear and thermal resistance on piston rings by plasma spray coating.


2007 ◽  
Vol 534-536 ◽  
pp. 89-92 ◽  
Author(s):  
Hyun Kwang Seok ◽  
Yu Chan Kim ◽  
Frédéric Prima ◽  
Eric Fleury

This works deals with the deposition of Ti-Zr-Ni icosahedral quasicrystalline powders by low vacuum plasma spray technique and the performances of the resulting coating layers. The microstructure of the coatings, as analyzed by X-ray diffraction and TEM techniques, consisted of nanometer-sized W-Ti50Zr35Ni15 1/1 cubic approximant and TiZrNi Laves phases as well as a low volume fraction of submicrometer-sized ZrO2 phase. The absence of the icosahedral phase in the coating layers was explained by the loss of Ti during plasma spraying. The shift in the composition and the presence of the ZrO2 phase within the coating layers are believed to be responsible for the reduced microhardness and corrosion performances evaluated by electrochemical tests in a Hanks’ Balance Salt Solution at 37oC.


2011 ◽  
Vol 20 (4) ◽  
pp. 967-973 ◽  
Author(s):  
Elliot M. Cotler ◽  
Dianying Chen ◽  
Ronald J. Molz

Author(s):  
A.Ph. Ilyuschenko ◽  
N.I. Shipica ◽  
P.A. Vityaz ◽  
A.A. Yerstak ◽  
A.Y. Beliaev

Abstract This paper presents the results of a study on the wear resistance of plasma spray coatings made from Cr2O3-TiO2-CaF2 powders. The composite powders used were produced by self-propagating high temperature synthesis. They were then applied under various conditions in order to optimize the material system, spray process, and application procedures. Based on the results of microstructural examination and wear testing, the thermally sprayed composite coatings have excellent wear resistance, good adhesion, and are self-lubricating at high temperatures.


2011 ◽  
Vol 328-330 ◽  
pp. 853-856 ◽  
Author(s):  
Sun Hui Yao ◽  
Yan Liang Su ◽  
Wen Xian Kao

This study aimed to understand the effect of TiO2 content on the thermal shock performance of Al2O3/TiO2 air plasma spray coatings. Three kinds of commercial feedstock powders were used, i.e. Al2O3, Al2O3-13wt%TiO2 and Al2O3-40wt%TiO2. The resulting coatings were studied in terms of micro Vickers hardness test, XRD, SEM and thermal shock test. The last was conducted using a water quenching method. The results showed that both the coating hardness and thermal shock performance decreased with the TiO2 content.


Sign in / Sign up

Export Citation Format

Share Document