Formation of Thermally Sprayed Coatings on Grid-Like Structure Substrate

2016 ◽  
Vol 258 ◽  
pp. 387-390 ◽  
Author(s):  
David Jech ◽  
Ladislav Čelko ◽  
Lenka Klakurková ◽  
Karel Slámečka ◽  
Miroslava Horynová ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Energy Dispersive Spectrometer ◽  
Atmospheric Plasma ◽  
Spray Coatings ◽  
Substrate Structure ◽  
Thermally Sprayed Coatings ◽  
Shadowing Effect ◽  
Ysz Coating ◽  
Thermally Sprayed ◽  
Sprayed Coatings

The main goal of this contribution is to investigate the influence of the substrate morphology on the resulting thermally sprayed coatings microstructure. Therefore, three different representative coating systems and/or thermal spray techniques were utilized to produce the coatings on grid-like structure substrates: (i) CoNiCrAlY bond coat (BC) sprayed by high velocity oxygen fuel (HVOF) technique and yttria stabilized zirconia (YSZ) top coat (TC) sprayed by means of atmospheric plasma spray (APS) technique, (ii) YSZ coating sprayed by means of APS and (iii) YSZ coating sprayed by means of nanoparticle colloid suspension plasma spraying (SPS). The shadowing effect of thermal spray coatings in relation with the grid-like substrate structure was investigated in detail. Resulting microstructure of sprayed samples was studied utilizing light microscopy, digital image analysis, scanning electron microscopy, energy-dispersive spectrometer and X-ray diffraction techniques.

In-Situ Observation and Ae Analysis of Microscopic Fracture Process of Thermal Spray Coatings

1998 ◽  
Author(s):  
K. Akita ◽  
G. Zhang ◽  
S. Takahashi ◽  
H. Misawa ◽  
S. Tobe
Keyword(s):  
Thermal Spray ◽  
Bonding Strength ◽  
Thermal Spray Coatings ◽  
Fracture Mechanisms ◽  
In Situ Observation ◽  
Spray Coatings ◽  
Thermally Sprayed Coatings ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Abstract Microscopic fracture mechanisms of thermal spray coatings under bending stress are investigated. Samples of thermally sprayed coatings were made using three distances. The sprayed powder was pure molybdenum. Vertical microcracks occur in lamellae and subsequently, these cracks join together and form vertical macrocracks in the samples sprayed with a short spraying distance. On the other hand, horizontal microcracks occur at the lamellae interfaces, and these cracks link together in the samples sprayed with a long spraying distance. These tendencies can be explained in terms of the hardness of the lamella and the bonding strength between each lamella. It is clarified that the bonding strength between each lamella corresponds to the applied strain at the point of rapid increase of the AE event count. The amplitude and rate of AE beyond the point of rapid increase are high in the coatings which formed macrocracks. It is concluded that the coating which has high resistance to crack formation has a high point of AE increase, low AE amplitude and low AE increasing rate.

Principles and Applications of Thermal Spray Coatings

2021 ◽  
pp. 31-70
Author(s):  
John Henao ◽  
Carlos A. Poblano-Salas ◽  
Fabio Vargas ◽  
Astrid L. Giraldo-Betancur ◽  
Jorge Corona-Castuera ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Thermal Spraying ◽  
Industrial Applications ◽  
Thermal Spray Coatings ◽  
Flame Spray ◽  
Spray Coatings ◽  
Thermal Barriers ◽  
Energy Conversion Devices ◽  
Thermally Sprayed ◽  
Sprayed Coatings

The goal of the chapter is to address the fundamental theory of thermal spraying and its modern industrial applications, in particular, those involving flame spray, HVOF, plasma spray, and cold spray processes. During the last 30 years, thousands of manuscripts and various book chapters have been published in the field of thermal spray, displaying the evolution of thermally sprayed coatings in many industrial applications. Thermal spray coatings are currently interesting for different modern applications including prosthesis, thermal barriers, electrochemical catalysis, electrochemical energy conversion devices, biofouling, and self-repairing surfaces. The chapter will explain the fundamental principles of the aforementioned thermal spraying processes and discuss the effect of different controlling parameters on the final properties of the produced coatings. This chapter will also explore current and future industrial applications of thermal spray coatings.

Optimization of the Characterization of Thermal Spray Coatings

2000 ◽  
Author(s):  
V. Begon ◽  
J. Baudoin ◽  
O. Dugne
Keyword(s):  
Point Of View ◽  
Constant Level ◽  
Spray Coatings ◽  
Thermal Barriers ◽  
Thermally Sprayed Coatings ◽  
The Subject ◽  
The Cost ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Abstract Thermal Barriers Coatings (TBC) are mass-produced in several industrial fields: aeronautic, automotive or energetic industries. All production requires the same constant level of fest and reproducible quality control at the lowest cost. The metallographic process is the primary way to evaluate thermally sprayed coatings but it must be both highly very repeatable and fast, especially when metallography is used to keep the production at a constant level. Therefore the management and the organization of a metallographic laboratory is of prime importance in order to reduce the cost and to provide a quality structure. The present approach to the whole chain of characterization is based on the user's point of view. Generally speaking, metallographic control of widely used parts often seems to be considered to be an uninteresting and obtuse subject, since it has been in practice for so long. Despite the lack of the prestige associated with the subject, optimization of an appraisal post can provide very concrete and more importantly profitable, results.

Thermal Spray Quasicrystalline Coatings Part II: Relationships Among Processing, Phase Assemblage, and Tribological Response

1998 ◽  
Author(s):  
S. De Palo ◽  
S. Usmani ◽  
K. Kishi ◽  
S. Sampath ◽  
D.J. Sordelet ◽  
...  
Keyword(s):  
Thermal Spray ◽  
High Hardness ◽  
Phase Assemblage ◽  
Low Friction ◽  
Thermal Spray Process ◽  
Ductile Materials ◽  
Spray Process ◽  
Thermally Sprayed Coatings ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Abstract AI-Cu-Fe quasicrystalline coatings, due to their high hardness and low friction coefficients, are potential candidates for improving the wear resistance of ductile materials. However, technological applications may be limited on account of their brittle nature. This study examines the effects of starting powder composition and thermal spray process parameters on the phase assemblage, microstuctures and tribological response of AI-Cu-Fe thermally sprayed coatings. It was found that the coatings fail by a delamination mechanism in unlubricated unidirectional sliding wear. Furthermore, the coatings produced by the high velocity oxy-fuel technique showed a very low coefficient of friction and wear rate.

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