scholarly journals A numerical and experimental investigation into residual stress in thermally sprayed coatings

2007 ◽  
Vol 44 (25-26) ◽  
pp. 8532-8555 ◽  
Author(s):  
A.M. Kamara ◽  
K. Davey
Keyword(s):  
Residual Stress ◽  
Experimental Investigation ◽  
Thermally Sprayed Coatings ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Simplified models for residual stress prediction in thermally sprayed coatings

2008 ◽  
Vol 222 (11) ◽  
pp. 2053-2068 ◽  
Author(s):  
A M Kamara ◽  
K Davey
Keyword(s):  
Residual Stress ◽  
Layer Thickness ◽  
Coating Thickness ◽  
Interfacial Stress ◽  
Analytical Models ◽  
Elastic Behaviour ◽  
Layer Deposition ◽  
Thermally Sprayed Coatings ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Residual stress in thermally sprayed coatings is known to cause a range of problems, notably debonding, cracking, and spallation. The focus in this paper is on the development of simple analytical models for the prediction of residual stress that arise from spraying a steel-alloy coating onto a copper-alloy substrate. This is a material combination that has been used recently to enhance the thermal and mechanical efficiency of the pressure die casting process although problems with debonding have been reported in the literature. Three analytical models are developed and investigated, where each represent combinations of assumptions for coating and substrate material behaviours during coating manufacture. The sensitivity of these combinations on residual stress, developed for a range of process parameters (deposited layer thickness, interval of layer deposition and the number of layers in a coating, i.e. block deposition versus multi-layer deposition for a desired coating thickness) is recorded. In agreement with experimental and finite-element modelling results from a previous study, the results from all the three models assessed in the current study indicate a progressive change in average interfacial residual stress from compressive towards tensile with an increase in the thickness of the deposited layer; and a tensile interfacial stress in a two-layer coating, which increases with an increase in the interval of deposition between the two layers. The observations from the results suggest an increase in potential for coating debonding with an increase in both deposited layer thickness and layer deposition interval. The results further suggest higher potential for coating debonding with block deposition compared with multi-layer deposition for a desired coating thickness. In terms of stress magnitudes, the model that performs best is one where the assumption that a currently deposited coating layer yields during its quenching phase and adopts elastic behaviour afterwards; and the strain generated in the substrate during the quenching phase is from thermal effect only while in the other phases afterwards, is from both thermal and elastic effects.

Finite Element Simulation of Residual Stress Development in Thermally Sprayed Coatings

2017 ◽  
Vol 26 (4) ◽  
pp. 735-744 ◽  
Author(s):  
Mohamed Elhoriny ◽  
Martin Wenzelburger ◽  
Andreas Killinger ◽  
Rainer Gadow
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Stress Development ◽  
Element Simulation ◽  
Thermally Sprayed Coatings ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Effect of Heat Treatment on Residual Stress of Cold Sprayed Nickel-Base Superalloys

2021 ◽  
Author(s):  
Deepika Shrestha ◽  
Fardad Azarmi ◽  
X.W. Tangpong
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Inconel 718 ◽  
Cold Spraying ◽  
Solid Particles ◽  
Inconel 625 ◽  
Thermal Expansion Coefficients ◽  
Thermally Sprayed Coatings ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Abstract Residual stress can be developed in most thermally sprayed coatings due to the momentum of molten particles during impact; and heat transfer during solidification of the splats. Another reason for residual stress built-up in thermally sprayed coatings is due to splat curl-up during solidification and the differences in thermal expansion coefficients between the coating and the substrate. However; in the cold spraying process; it is believed that the main reason for residual stress formation is plastic deformation during impact and flattening of solid particles. Residual stresses can drastically influence coating quality and reduce its service time. In this study; residual stress is measured for two well-known nickel based super alloys (Inconel 625 and Inconel 718) deposited on 7074 aluminum alloy substrates by the cold spraying technique. Residual stress in Inconel 625 was found to be highly tensile on the surface and compressive on the subsurfaces. After heat treatment the residual stress was relieved and was compressive in nature. Whereas for Inconel 718; residual stress was compressive on the surface and tensile on the subsurfaces in the as-sprayed condition. After heat treatment; the residual stress was compressive with increased magnitude. The heat treatment at 800°C made the residual stress more compressive. The porosities of both Inconel 625 and Inconel 718 were reduced after heat treatment.

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