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

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.

scholarly journals Finite Element Simulation of Interface Bonding in Kinetic Sprayed Coatings

2008 ◽  
Vol 26 (6) ◽  
pp. 74-80
Author(s):  
Gyu-Yeol Bae ◽  
Ki-Cheol Kang ◽  
Sang-Hoon Yoon ◽  
Chang-Hee Lee
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Interface Bonding ◽  
Element Simulation ◽  
Sprayed Coatings

Finite Element Simulation of Welding of Large Structures

1992 ◽  
Vol 114 (4) ◽  
pp. 441-451 ◽  
Author(s):  
S. Brown ◽  
H. Song
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Three Dimensional ◽  
Mechanical Analysis ◽  
Welding Distortion ◽  
Surrounding Structure ◽  
Element Simulation ◽  
Weld Distortion ◽  
Welding Processes

Current simulations of welding distortion and residual stress have considered only the local weld zone. A large elastic structure surrounding a weld, however, can couple with the welding operation to produce a final weld state much different from that resulting when a smaller structure is welded. The effect of this coupling between structure and weld has the potential of dominating the final weld distortion and residual stress state. This paper employs both two-and three-dimensional finite element models of a circular cylinder and stiffening ring structure to investigate the interaction of a large structure on weld parameters such as weld gap clearance (fitup) and fixturing. The finite element simulation considers the full thermo-mechanical problem, uncoupling the thermal from the mechanical analysis. The thermal analysis uses temperature-dependent material properties, including latent heat and nonlinear heat convection and radiation boundary conditions. The mechanical analysis uses a thermal-elastic-plastic constitutive model and an element “birth” procedure to simulate the deposition of weld material. The effect of variations of weld gap clearance, fixture positions, and fixture types on residual stress states and distortion are examined. The results of these analyses indicate that this coupling effect with the surrounding structure should be included in numerical simulations of welding processes, and that full three-dimensional models are essential in predicting welding distortion. Elastic coupling with the surrounding structure, weld fitup, and fixturing are found to control residual stresses, creating substantial variations in highest principal and hydrostatic stresses in the weld region. The position and type of fixture are shown to be primary determinants of weld distortion.

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