Metallurgical Characterization and Determination of Residual Stresses of Coatings Formed by Thermal Spraying

Correlation Between Chemical Composition and Adherence of Cr and Co Coatings Deposited by Electric Arc

“…The adhesion strength of a coating depends on the bonding between the coating and substrate and both the bonding and the microstructure are strongly influenced by the residual stress distribution [4,8]. It is commonly known that the level of residual stress can significantly change at the coating substrate interface, creating delamination, which in the worst case causes spallation.…”

“…A good microstructural evaluation is important in the analysis of adhesion results. Laribi et al [8] in a metallographic study focused on the substratedeposit interface to examine the diffusion and adhesion phenomena at the interface. The main result shows that phase transformations in both coating and substrate lead to refined microstructures and a more homogenous distribution of inclusions, carbides, and oxides.…”

Study of microstructure, phases and microhardness of metallic coatings deposited by flame thermal spray

“…Therefore, the Vickers microhardness experiments always show a maximum in the middle of Mo bond coating, with a maximum value increasing with the Mo bond coating thickness. This property could be related to the presence of residual mechanical stresses which develop in the process of any metal coating on a given substrate (Laribi et al, 2001(Laribi et al, , 2003. It is suggested that strong residual stresses in tension are present in the layers of the coating due to the addition of the individual stresses generated around solidified particles.…”

“…These stresses probably result from anisotropic thermal contraction of the particles. These residual stresses are known to be more severe if pulverized particles are deposited in a molten state (Laribi et al, 2001).…”

Finite element analysis of residual stress in plasma-sprayed ceramic coatings

“…They also have a fundamental influence on coating structure and substratecoating adhesion, thus strongly affecting deposit performance in working conditions. Different experimental techniques are available nowadays for their direct measurement or indirect evaluation [4][5][6][7][8][9][10], such as X-ray or neutron diffraction methods, curvature measurements, high-speed hole drilling techniques and metallurgical and layer removal methods. However, numerical modelling tools [11,12] offering reliable predictions of the mechanical properties of a selected substrate -coating system on the basis of the operating conditions of the manufacturing process are of even greater importance, assisting processing parameter optimization procedures, saving time and reducing the economic impact of the trial and error approach.…”